godina (volume) 14 broj (number) 2, april - juni (april

Microsoft Word - Prva stranahttp://www.mf.unze.ba/Masinstvo
Godina (Volume) 14 Broj (Number) 2, April - Juni (April - June) 2017.
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MAŠINSTVO ASOPIS ZA MAŠINSKO INENJERSTVO
JOURNAL OF MECHANICAL ENGINEERING Godina (Volume) 14, Broj (Number) 2, Zenica, April – Juni (April – June) 2017.
Uredništvo (Editorial): Fakultetska 1, 72000 Zenica Bosnia and Herzegovina Tel: +387 32 449 145 Fax: +387 32 246 612 e-mail: [email protected] [email protected] [email protected]
Osniva i izvršni izdava (Founders and Executive Publisher): University of Zenica Faculty of Mechanical Engineering Fakultetska 1, 72000 Zenica Bosnia and Herzegovina Recenzioni odbor (Review committe): Dr. Nermina Zaimovi-Uzunovi, Dr. Fuad Hadikaduni, Dr. Safet Brdarevi, Dr. Sabahudin Jašarevi, Dr. Nedeljko Vukojevi
Glavni i odgovorni urednik (Editor and Chief): Prof. Dr. Sc. Safet Brdarevi
asopis izlazi tromjeseno (The journal is published quarterly)
Uredniki odbor (Editorial Board): Dr. Safet Brdarevi (B&H), Dr. Joe Duhovnik (Slovenia), Dr. Vidosav Majstorovi (Serbia), Dr. Milan Jurkovi (Croatia), Dr. Sabahudin Ekinovi (B&H), Dr. Gheorge I. Gheorge (Romania), Dr. Alojz Ivankovi (Ireland), Dr. Joan Vivancos (Spain), Dr. Ivo ala (Croatia), Dr. Slavko Arsovski (Serbia), Dr. Albert Weckenman (Germany), Dr. Ibrahim Paši (France), Dr. Zdravko Krivokapi (Montenegro), Dr. Rainer Lotzien (Germany)
Tehniki urednik (Technical Editor): Prof. Dr. Sabahudin Jašarevi Štampa (Print): Štamparija Fojnica d.o.o., Fojnica Ureenje zakljueno (Preparation ended): 30.06.2017.
asopis je evidentiran u evidenciji javnih glasila pri Ministarstvu nauke, obrazovanja, kulture i sport Federacije Bosne i Hercegovine pod brojem 651. asopis u pretenom iznosu finansira osniva i izdava. asopis MAŠINSTVO u pravilu izlazi u etiri broja godišnje. Rukopisi se ne vraaju
The Journal is listed under No 651 in the list of public journals in the Ministry of science, education, culture and sport of the Federation of Bosnia and Herzegovina. The Journals is mostly financed by founder and publisher. Frequency of Journal MAŠINSTVO is 4 issues a year. Manuscripts are not returned
asopis objavljuje naune i strune radove i informacije od interesa za strunu i privrednu javnost iz oblasti mašinstva i srodnih grana vezanih za podruje primjene i izuavanja mašinstva. Posebno se obrauju slijedee tematike: - tehnologija prerade metala, plastike i gume, - projektovanje i konstruisanje mašina i postrojenja, - projektovanje proizvodnih sistema, - energija, - odravanje sredstava za rad, - kvalitet, efikasnost sistema i upravljanje proizvodnim i poslovnim sistemima, - informacije o novim knjigama, - informacije o naunim skupovima - informacije sa Univerziteta,
The journal publishes scientific and professional papers and information of interest to professional and economic releases in mechanical engineering and related fields. In particular, the following topics are treated: - Technology for processing metal, plastic and rubber, - Design and construction of machines and plants, - The design of production systems, - Energy, - Maintenance funds for the work, - Quality and efficiency of the system and the management of production and business systems, - Information about new books, - Information about scientific meetings - Information from the University,
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RIJE UREDNIKA Poštovane kolegice i kolege U 54 broju etrnaeste godine izlaenja asopisa „MAŠINSTVO“ predstavljamo Vam 4 rada, od kojih je jedan namjenski napisan za asopis i tri rada preuzeta sa dvije nauno-strune konferencije, gdje su bili uvodni referati. Radovi su iz razliitih oblasti mašinstva: Analiza ošteenje koinog diska koordinatnom mjernom mašinom i 3D modeliranjem (odravanje, tehnika dijagnostika, modeliranje), poboljšanje strategije kvaliteta – Opšti cilj, razliite metode (upravljanje kvalitetom), Evaluacija radne uspješnosti akademskog osoblja (upravljanje ljudskim resursima u specifinim poslovnim sistemima) te Odravanje i uinak strojeva na gradilištima (odravanje, upravljanje proizvodnim sistemima). Takoe Vas informišemo o novoj konstrukciji CNC mašine, autora Amera Sarajlia, mladog ininjera i uskoro poduzetnika kroz realizaciju projekta uz pomo Agencije za razvoj ZEDA iz Zenice. Tu su informacije i o Nauno-strunom skupu QUALITY 2017 i Okruglom stolu Upravljanje kvalitetom u visokoškolskim organizacijama u BiH. Na prvoj strani korica predstavljamo jednu Laboratoriju Tehnikog fakulteta iz Bihaa, a na zadnjoj strani korica predstavljamo jednu uspješnu BiH firmu iz oblasti metalskog kompleksa. Pozivamo Vas da date svoj doprinos asopisu Mašinstvo na Vašu korist, korist struke i nauke.
Vaš glavni i odgovorni urednik Prof. emeritus dr. Safet Brdarevi
EDITORIAL Dear Colleagues In the 54 issue of the fourteenth year of publishing the Journal "MAŠINSTVO" we present you 4 papers, one of which was dedicated to the journal and three papers were taken from two scientific and professional conferences, where they were introductory papers. The papers are from different fields of machinery: Analysis of disc brake fracture by a coordinate measuring machine and 3D modeling (maintenance, technical diagnosis, modeling), Improvement of the quality strategy - General objective, different methods (quality management), Academic staff performance evaluation (Human Resource Management in Specific Business Systems) and Maintenance and impact of machinery on construction sites (maintenance, production system management). We also inform you about the new construction of the CNC machine, the author of Amer Sarajli, a young engineer and soon an entrepreneur through the project implementation with the ZEDA Development Agency from Zenica. There is also information on the Scientific and Professional Conference QUALITY 2017 and the Round Table on Quality Management in Higher Education Organizations in BiH. On the first side of the hoop we present one Laboratory of the Technical Faculty from Biha, and on the back of the platform we present one successful BiH company in the field of metal complex. We invite you to give your contribution to the Journal Machine for your benefit, the benefit of the profession and the science.
Your editor in chief Prof. emeritus dr. Safet Brdarevi
SADRAJ
1. Analiza ošteenja koionog diska koordinatnom mjernom mašinom i 3D CAD modeliranjem Kari A., Lemeš S. 69
2. Strategije poboljšanja kvaliteta Zajedniki cilj i raznovrsnost naina Hamrol A. 75
3. Evaluacija radne uspješnosti akademskog osoblja – Objektivni model Dedi E. 81
4. Odravanje i uinak strojeva na gradilištima Vidakovi D., Lackovi Z., Ivanovi M. 91
Informacije 105
CONTENTS
1. Analysis of Disc Brake Fracture Using Coordinate Measuring Machine and 3D CAD Modeling
Kari A., Lemeš S. 69
2. Quality Improvement Strategies Common Goal And Variety Of Ways Hamrol A. 75
3. Academic Staff Evaluation – Objective Model Dedi E. 81
4. Maintenance And Effect Of Machines Worked On Construction Site Vidakovi D., Lackovi Z., Ivanovi M. 91
Information 105
Instruction for authors 116
Mašinstvo 2(14), 69 – 74, (2017) A. Kari and S. Lemeš: ANALYSIS OF DISC BRAKE…
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ANALIZA OŠTEENJA KOIONOG DISKA KOORDINATNOM MJERNOM MAŠINOM I 3D CAD MODELIRANJEM
ANALYSIS OF DISC BRAKE FRACTURE USING COORDINATE
MEASURING MACHINE AND 3D CAD MODELING
Amel Kari1, Samir Lemeš2 University of Zenica 1Faculty of Mechanical Engineering 2Polytechnic Faculty Kljune rijei: disk konice, ošteenje Keywords: disc brakes, fracture Paper received: 27.01.2017. Paper accepted: 19.04.207.
Struni rad REZIME Koioni disk je u toku svog radnog vijeka izloen razliitim optereenjima koja uzrokuju trošenje koione površine, deformaciju, promjenu strukture, pojavu zaostalih napona itd. Cilj ovog rada je mjerenjem ravnosti i potrošenosti koione površine utvrditi glavni uzrok pojave pukotina na koionoj povšini, te dati glavne smjernice u cilju produavanja ivotnog vijeka koionog diska i spreavanja katastrofalnog otkaza. Za mjerenje ravnosti i potrošenosti koione površine korištena je koordinatna mjerna mašina Zeiss Contura G2, a podaci su dodatno analizirani u 3D CAD softveru Solidworks.
Professional paper
SUMMARY A brake disc is exposed to various loads during its operational life, which cause braking surface wearing, disc deformation, structural changes, residual stresses etc. The goal of this paper is to find out the main cause of fractures on braking surface, by measuring flatness and wear of braking surface, and to give main guidelines to prolong the operational life and to prevent catastrophic failures. Measurement of flatness and wear was performed on coordinate measuring machine Zeiss Contura G2. Obtained results are then further analyzed using 3D CAD software Solidworks.
1. INTRODUCTION The main purpose of brake is to decelerate or to stop the moving vehicle. In that process, friction causes vehicle deceleration, but also heats the braking system. Braking systems act as heat accumulators, where kinetic energy is absorbed in braking systems as heat, or transfers to air by convection. Focus of this paper is to determine the main cause of brake disc fracture using coordinate measuring machine Zeiss Contura G2 and 3D CAD software Solidworks. The analysis was carried out on a brake disc of Mercedes Atego truck, on which two radial cracks were spotted (Figure 1). Amongst numerous papers that analyzed this topic, the work of scientists H. Abendroth, T. Steffen, W. Falter and R. Heidt should be emphasized. They described in detail the process of cracks creation in presence of braking load and brake disc overheating, and they performed the analysis by both numerical and experimental tests [1].
1. UVOD Osnovna funkcija konice je da uspori ili zaustavi kretanje vozila. Pri tome se javlja trenje, koje usporava automobil, ali i zagrijava koioni sistem. Koioni sistemi se ponašaju kao toplotni akumulatori, u kojima se kinetika energija apsorbuje u obliku toplote unutar koionih sistema ili se konvekcijom prenosi na zrak. Ovaj rad je usmjeren na otkrivanje glavnog uzroka otkaza koionih diskova korištenjem koordinatne mjerne mašine Zeiss Contura G2 i 3D CAD softvera Solidworks. Analiza je izvršena na koionom disku kamiona Mercedes Atego, na kojem su ustanovljene dvije radijalne pukotine (Slika 1.) Od mnogobrojnih istraivanja koji su analizirali ovaj problem, posebno treba istai rad naunika H. Abendroth, T. Steffen, W. Falter i R. Heidt, koji su detaljno opisali proces nastajanja pukotine u prisustvu optereenja i povišene temperature koionog diska, a istraivanje su proveli i numerikim i eksperimentalnim provjerama [1].
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a.) b.) Slika 1. Pukotine na koionoj površini diska (a – vanjska površina, b – unutrašnja površina)
Figure 1. Cracks on braking surface of the disc (a – inner surface, b – outer surface)
Convection and conduction heat process inside braking systems were described in details by A.R. Daudi and M. Narrain, who applied CAE and FEM technologies in their work [2]. 2. BASIC INFORMATION ABOUT DISC
BRAKES Main characteristics of disc brakes:
• Simple construction, • Rapid cooling, • Rapid drying, • Braking intensity control.
Brake disc fracture occurs commonly, and one could search for a cause in some of the following factors:
• Wear of brake disc, • Surface inhomogeneities (decorative
openings, vents, eccentricity), • Corrosion.
Brake disc wear is an inevitable phenomenon, as a result of constant friction of brake pads, as well as of multiple machining process to flatten braking surface. Corrosion is a phenomenon which every braking system is faced with. If a vehicle is in permanent use, the braking surface is protected from corrosion by continuous friction wear. In case of vehicles, that are not being used for a longer time, corrosion damages braking surface, and the first use that follows, the damages cause unevenness, rapid wear and additional heating. Vented brake discs are more exposed to corrosion, which penetrates into the structure and can cause fracture. The occurrence of cracks on brake disc indicates that disc should be replaced. Cracks on the disc cause impacts during braking, uneven heating and rapid wearing of braking surface, and all this finaly causes the cracks to rapidly expand in depth of material. If brake disc with crack is not replaced in a timely manner, the disc often
Proces konvekcije i kondukcije toplote unutar koionih sistema detaljno su opisali A.R. Daudi i M. Narrain, koji su u svom istraivanju primijenili CAE i MKE tehnologije [2]. 2. OSNOVNI PODACI O DISK
KONICAMA Osnovne karakteristike disk konica:
• Jednostavna konstrukcija, • Brzo hlaenje, • Brzo sušenje, • Kontrola intenziteta koenja.
Problem pucanja koionog diska je esta pojava u praksi, a uzrok se moe traiti u nekom od sljedeih faktora:
• Istrošenost koionog diska, • Nehomogenost površine (ukrasni i
ventilacioni otvori, ekscentrinost), • Korozija.
Istrošenost koionog diska je neminovna pojava, a rezultat je stalnog trenja disk ploica, ali i višestruke strojne obrade u cilju poravnavanja koione površine. Korozija je pojava sa kojom je suoen svaki koioni sistem. Ukoliko je vozilo u stalnoj upotrebi, koiona površina je zaštiena od korozije zbog stalnog trošenja trenjem. Kod vozila koja se due vremena ne koriste, korozija napada koionu površinu ošteujui je, a tokom prve naredne upotrebe tako nastala ošteenja uzrokuju neravnine, ubrzano trošenje i dodatno zagrijavanje. Koioni diskovi sa ventilirajuim otvorom su naroito izloeni koroziji, koja ulazi u strukturu i moe uzrokovati lom. Pojava pukotine na disku je pokazatelj da je disk potrebno zamijeniti. Pukotine na disku uzrokuju udare pri koenju, neravnomjerno zagrijavanje i ubrzano trošenje ploice, a sve to dovodi do ubrzanog širenja pukotine u dubinu materijala. Ukoliko se koioni disk sa pukotinom na vrijeme ne zamijeni, esto se desi da se disk u potpunosti
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completely falls apart, which can lead to catastrophic consequences. 3. EXPERIMENTAL DETERMINATION
OF DISC BRAKE FAILURE CAUSE The braking surface flatness was measured by scanning with circular path of measuring tool. The measurement was performed by 8 different radii arranged in the following way:
• The inner surface was measured by circular paths with radii: 250, 270, 310, 330, and 350 mm,
• The outer surface was measured by circular paths with radii: 310, 330, and 350 mm.
Software of the measuring machine allows three- dimensional preview of the results, but in order to obtain real picture of surface curvature, further data processing must be done. In order to obtain a clearer picture of brake disc surface curvature, and since the surface flatness deviation is not visible by naked eye, measured coordinates are processed with MS Excel, multiplying the difference between the mean of z-axis coordinates and the current values of z- axis coordinates with a certain scaling factor, according to the expression: ∑ (1) where: k – scaling factor, j - number of the measured point, n - total number of points, For this example the scaling factor was k=30.
raspadne, što moe uzrokovati katastrofalne posljedice. 3. EKSPERIMENTALNO
ODREIVANJE UZROKA OTKAZA KOIONOG DISKA
Ravnost koione površine izmjerena je krunom putanjom mjernog alata. Mjerenje je izvršeno sa ukupno 8 definisanih radijusa rasporeenih na sljedei nain:
• Unutrašnja površina izmjerena je na krunim putanjama radijusa 250, 270, 290, 310, 330 i 350 mm,
• Vanjska površina je izmjerena po krunim putanjama radijusa 310, 330 i 350 mm.
Softver mjerne mašine omoguava 3D prikaz rezultata, ali, da bi se dobila stvarna slika površine koionog diska, potrebno je dodatno obraditi dobivene rezultate. Da bi se dobila jasnija slika zakrivljenosti koione površine diska i s obzirom da odstupanje ravnosti površine nije vidljivo golim okom, izmjerene koordinate su pomou MS Excel preraene mnoenjem razlike srednje vrijednosti z-koordinate i trenutne vrijednosti z-koordinate odreenim faktorom uveanja, prema izrazu: ∑ (1) gdje je: k - faktor uveanja, j - redni broj izmjerene take, n - ukupan broj taaka, Za ovaj primjer faktor poveanja je k=30.
Slika 2. Izmjerene take na koionoj površini diska uitane u softver Solidworks
Figure 2. Measured points on braking surface loaded in Solidworks software
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The coordinates of measured points are imported into Solidworks 3D model using "Scan to 3D" from the "Add-ins" menu. In this example, all measured points are loaded together, for better visualisation of surface curvature (Figure 2). In order to further improve the surface model created, loaded points were connected into curves, and a curved surface which closely reflects the actual state of the curvature of the brake disk surface was created. The curved surface could be created in several ways, but for this example, function "Surface Loft" from the menu "Insert Surface" was used. However, creating surface in this way requires all points measured with the same measurement radius to be connected with a curve. Even this is quite a tedious job, the surface created in this way precisely describes the curvature of the original disc surface. The final appearance of the surface reveals many minor variations that are present across the entire surface. However, the most important thing to note is the curvature of the brake disc surface in the radial (Figure 3) and polar direction (Figure 4), which are present on both sides of the disc.
Koordinate taaka se u 3D Solidworks model unose naredbom "Scan to 3D" iz menija "Add- ins". U ovom primjeru su radi jasnijeg prikaza ravnosti uitane istovremeno koordinate svih taaka obje površine (Slika 2). S ciljem daljeg unapreenja jasnoe prikaza uitane take su povezane krivuljama i kreirana je zakrivljena površina koja priblino prikazuje stvarno stanje zakrivljenosti koione površine diska. Povezivanje taaka u zakrivljenu površinu mogue je izvršiti na više naina, a za ovaj primjer korištena je funkcija "Surface Loft" iz menija "Insert Surface". Meutim, da bi se na ovaj nain kreirala površina, potrebno je prethodno sve take jedne krunice spojiti jednom krivuljom. Iako je to dosta zahtjevan zadatak, površina kreirana na ovaj nain precizno opisuje zakrivljenost površine. Konaan izgled površine pokazuje mnogo manjih neravnina koje su prisutne du cijele površine. Meutim, najznaajnije je primijetiti savijenost površine koionog diska u radijalnom pravcu (Slika 3) i u polarnom pravcu (Slika 4) koje su prisutne na obje strane diska.
Slika 2. Zakrivljenost koione površine u radijalnom pravcu Figure 3. Curvature of braking surface in radial direction
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Slika 3. Zakrivljenost koione površine u polarnom pravcu Figure 4. Curvature of braking surface in polar direction
Slika 4. Pozicija pukotine na unutrašnjoj površini diska
Figure 5. Crack position on the inner side of the disc 4. CONCLUSION The appearance of radial cracks could be directly related to curvature in radial direction, because of which uneven pressure of braking pads on disc surface causes additional bending stresses (Figure 3). Curvature in polar direction (Figure 4) causes impacts and vibrations, which have additional negative influence on braking disc stress state. Impacts cause dynamic load, which causes cracks even with normal load intensity, and it also causes faster propagation of cracks. Overheating, as a main cause of braking surface deflection, could be prevented by regular cleaning and corrosion protection of venting opening whenever brake pads are replaced. Installation of sensors that would signal overheating of brake disc would almost completely eliminate the problem of overheating. Bimetal switches which would trigger the alert sound, or turn on signal light in
4. ZAKLJUAK Izgled radijalnih pukotina moe se direktno povezati sa savijenošu u radijalnom pravcu usljed koje neravnomjeran pritisak koione ploice uzrokuje dodatne savojne napone (Slika 3). Neravnost u polarnom pravcu (Slika 4) je uzronik udara i vibracija koje dodatno negativno utiu na naponsko stanje diska. Udari uzrokuju dinamiko optereenje koje dovodi do pojave pukotina ak i pri normalnom optereenju, a dodatno pospješuje i propagaciju pukotina. Pregrijavanje kao osnovni uzrok pojave neravnina na koionom disku moe se sprijeiti redovnim išenjem i zaštitom od korozije ventilirajueg otvora pri svakoj izmjeni koionih ploica. Ugradnja senzora koji bi signalizirali pregrijanost koionog diska bi skoro u potpunosti eliminisala problem pregrijavanja. Kao senzori mogle bi se koristiti i bimetalne
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case of overheating, could also be used as sensors. In case of modern car models with central coumputer, brake disc overheating could be signalised on central display.
sklopke, koje bi u sluaju pregrijavanja proizvodile upozoravajui zvuk ili bi upalile signalnu lampicu na instrument tabli vozila. Kod modernijih modela automobila sa centralnim kompjuterom, pregrijavanje konice bi se moglo signalizirati na centralnom ekranu.
5. REFERENCES - LITERATURA [1] H. Abendroth, T. Steffen, W. Falter, R.
Heidt. Investigations of CV rotor cracking test procedures. Professional Engineering Publishing, 2000. Brakes 2000. pp. 149- 163.
[2] Gajek, A. Testing of ABS operation in stand conditions. Professional Engineering Publishing, 2000. Brakes 2000. pp. 229- 239.
[3] Reif, Konrad. Fundamentals of Automotive and Engine Technology. Friedrichshafen, Germany: Springer Vieweg, 2014.
[4] M. Oru, R. Sunulahpaši. Lomovi i osnovi mehanike loma. Zenica: Univerzitet u Zenici, Fakultet za metalurgiju i materijale, 2009.
[5] Daudi A.R., Narain M. CAE prediction and experimental verification of maximum temperature of cool running 72 curve fin brake rotor design. Professional Engineering Publishing, 2000. Brakes 2000. pp. 123-139.
[6] Wirth A., McClure S., Anderson D.
Thermally sprayed surface coatigs suitable for use in automotive brake and clutch applications. Professional Engineering Publishing, 2000. Brakes 2000. pp. 175- 185.
[7] Roger L. Vehicle sensitivity to brake torque differences - test and simulation results. Professional Engineering Publishing, 2000. Brakes 2000. pp. 239-251.
[8] Koetniyom S., Brooks P.C. , Barton D.C. Finite element prediction of inelastic strain accumulation in cast-iron brake rotors. Professional Engineering Publishing, 2000. Brakes 2000. pp. 139-149..
Coresponding author: Amel Kari University of zenica, Mašinski fakultet Email: [email protected] Phone: +387 32 449 120
Mašinstvo 2(14), 75 – 80, (2017) A. Hamrol: QUALITY IMPROVEMENT STRATEGIES…
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STRATEGIJE POBOLJŠANJA KVALITETA
Adam Hamrol Poznan University of Technology, Department of Management and Production Engineering Kljune rijei: kvalitet, kontinuirana poboljašnja, Six Sigma, TQM, Kaizen Keywords: quality, continuous improvement, Six Sigma, TQM, Kaizen Paper received: 25.04.2017. Paper accepted: 10.05.2017.
Conference paper SUMMARY For about sixty years principles of TQM, Kaizen, Six Sigma and others continuous improvement strategies (CIS) play a vital role in quality engineering and management. They are presented in many books, scientific and professional journals, consulting companies offers and first of all in the Internet as an easy tool (almost a patent) for an efficient running a company and its never ending improvement. The goal of this paper is presentation and systematisation of relation existing between all these CIS. It is indicated in the paper that all off them make use of a common set of principles, methods and tools. Great attention is paid to one of author’s observation, that CSI allow professionals (e.g. designers, technologists, managers) more efficient usage of their knowledge, especially tacit knowledge. It is stressed their importance in creating a friendly environment for harmonious development of so called hard and soft skills and competences. However the condition is a systematic and not occasional use of them.
Rad sa konferencije
REZIME Prije oko šezdeset godina principi TQM-a, Kaizen-a, Six Sigma i drugih strategija kontinuiranog poboljšanja (CIS) odigrale su kljunu ulogu u inenjeringu i menadmentu kvalitete. Predstavljeni su u mnogim knjigama, naunim i strunim asopisima, konsultantske firme nude ih prije svega na Internetu kao jednostavan alat (gotovo patent) za uinkovito poslovanje firme i njeno kontinuirano poboljšanje. Cilj ovog rada je ppokazati i sistematizovati odnose izmeu svih ovih strategija kontinuiranog poboljšanja. U radu je naznaeno da se svi oni koriste zajednikim skupom naela, metoda i alata. Velika panja posveena jee jednom autorovom promatranju, da strategije kontinuiranog poboljšanja dopuštaju strunjacima (npr. dizajneri, tehnolozi, menaderi) uinkovitije korištenje njihova znanja, posebno tercijalnog (prešutnog) znanja. Naglašava se njihova vanost u stvaranju prijateljskog okruenja za usklaen razvoj tzv. tvrdih i mekih vještina i kompetencija. Meutim, stanje je njihova sustavna i ne povremena upotreba.
1. INTRODUCTION
Principles, methods and tools gathered under names of TQM, Kaizen, Six Sigma and Lean have been receiving considerable attention and recognition among practitioners and scientists for several dozen years. In many sources, such as books, journals, Internet and offers of counseling companies, they are often presented as the “golden mean” for constant quality improvement. This means improving a company, including realized processes, produced goods or offered services. However, these tools are seen very differently, as a philosophy, a concept or a
strategy of improvement [5]. Each of these roles has its justification. They are a philosophy, because they explain a reason behind the constant improvement. They have a character of a concept, because they give a general idea of improvement and allow selecting what is the most beneficial for a given company. Lastly, they are strategies, as aim of their use is obtaining competitive advantage.
TQM, Kaizen, Six Sigma and Lean are products which are greatly advertised and sold, but they are too often taken without any criticism whatsoever. Poland is a good example for this.
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Experiencing with them in Poland began when the command economy, dominated by orders and controlled distribution, ceased to exist. During transition into the market economy, Polish companies have been greedily acquiring all the novelties arriving from the western countries [6]. The companies introducing their departments in Poland have transferred ready organizational solutions, as well as elements of their work culture alongside technologies and machines. It should be acknowledged that it gave us a mighty impulse for development [1]. However, this enthusiasm suppressed any critical attitude in majority of managers. A wonderful idea by Deming to name the cycle of efficient operation as the PDCA cycle was acknowledged without any criticism – if possible, managers wanted to explain everything what was to be done in companies on the basis of its principle. In a nutshell, people believed and often still believe that everything that comes “from there” is better, more effective and efficient.
Of course, it must be admitted that what is proposed, for example, by the Japanese school, is worth respecting. But the Japanese methods are not a panacea. Being able to appreciate achievements of others, we must be also able to look on them with a healthy dose of criticism and look for our own way, if they do not fit into our conditions. The more so that in the past, also during the command economy era, Polish scientists and practitioners had some brilliant ideas for improving operation of companies. Today, we have enough knowledge and many own experiences to present courage of own interpretation and implement own solutions, also in scope of organization and management of a company, fitting our organizational and work culture.
2. STRATEGIES OF EXPEDITIOUS OPERATION
As regards the TQM, Kaizen, Six Sigma, Lean and ISO 9000, their importance in continuous improvement is emphasized [2,3,7]. They also have a strong position for application during phases of ensuring and maintaining proper conditions for realization of processes [2]. That is why the author calls them the Strategies of Expeditious Operation (SEO). The notion of
1 The Bourgeois Gentleman, Molière, 1670
“expeditious operation” is broad enough to contain effects of all the activities in a company –not only concerning the improvement. They are a support in each phase of the Product Life Cycle (PLC). Tools and methods of Lean and Six Sigma are irreplaceable in ensuring proper conditions, while standardized management systems, such as systems compatible with ISO 9001, are helpful in maintaining them. Aim of all the described concepts – although to a various degree – is quality improvement, lowering of costs and supplying products in time.
It must be clearly emphasized, that founding rules of SEO were used since the very first moment the human started to consciously manage resources at his disposal. That is because they are based on common sense and result directly out of practice of daily work. Everyone wants to lose as little time and money as possible, avoid wastage, which is applying the main Lean principle in daily life. Everyone, before deciding about any change, first defines a need for it and then tries to assess both possibilities and potential risks of its implementation. Consequently, the change is introduced and then an evaluation is formulated whether it was beneficial or not. Therefore, PDCA cycle is unconsciously realized. Often we determine the weakest links in a stream of our daily activities, e.g. by avoiding particularly crowded junctions or by leaving at a specific day time to avoid traffic jam – in other words, we utilize the Lean principles. We try to introduce small improvements around ourselves to help in our daily lives, inadvertently creating new Kaizen. The TQM also accompanies us secretly in our daily life. An example could be engaging the whole family in organization of Christmas holidays, with more or less aware attempt to reinforce bonds and improve mutual understanding. It is probably appropriate to compare it all to a famous quote from Molière – “Good heavens! For more than forty years I have been speaking prose without knowing it.”1 Through analogy to the Molière character, we have been always applying TQM, Lean, Kaizen but only when they were named, we realized their significance.
SEO are not scientific theories, they are above all a set of practical rules and principles and methods and tools of continuous improvement, aiding them on an operational level. They
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developed spontaneously, they had and still have hundreds of interpreters. That is why their recognition is fuzzy and ambiguous. For some, Kaizen is part of Lean and for others – the other way around. For many, the TQM is an organized system, for some – it is a set of rules to obey. There can be an impression that “everything is everything”. On the other hand, there is nothing wrong with it, as not the whole concepts of Lean or Six Sigma are used daily, but rather specific tools and methods related to them, such as the control chart, Pareto analysis, Kanban or SMED – how to use them is beyond any doubt. But this lack of agreement regarding the nomenclature is a certain hindrance in communication between both practitioners and theoreticians of continuous improvement.
Despite existing differences, SEO are complementary towards each other. Relations between the strategies can be schematically presented as in Fig. 1 and describe as a commentary below:
“High efficiency of operations is a challenge for each company. The effects do not come by themselves, hard work is necessary. Achieving, maintaining and improving high efficiency can be imagined as rolling a stone upwards a slope. Height of the stone is here a metaphor for efficiency and the slope – difficulties which are to overcome while maintaining and improving it. A moment of hesitation and the stone goes down. Maintaining of achieved level and improving it cannot be stopped – being aware of this means building the TQM. The TQM creates a thought climate from the client’s viewpoint – fulfilling his requirements. But the TQM is, to a large extent, a way of building good solutions by convincing, influencing and calling to
consciousness of employees. An ally, a partner and in many cases an equivalent of the TQM thinking is the Kaizen culture – allowing to smoothen the road, to reduce roughness. After certain time, TQM and Kaizen may become insufficient. That is why good practices and effective solutions must be solidified. The “solidifier” role is played by the standards, it is the best if they are created according to guidelines and requirements by a known other standard – the most recognized one is the ISO 9000. Implementation of a standard is a support (illustrated by the “wedge” in the Figure), preventing sliding of the cylinder of efficiency (expeditiousness, effectiveness, benefit).
The TQM and Kaizen build a friendly environment for achieving high expeditiousness of operations. However, they are not aggressive enough towards the costs. In this scope, they are aided by Lean, TOC and Six Sigma. They underline significance of financial side of the improvement, simultaneously making the road to high efficiency less steep (inclination of the slope is reduced) and they give additional impulse for improvement (the Six Sigma pushes the cylinder of efficiency), not in the role of the proverbial Sisyphus, but as an efficient tool.” Even if the narration presented above is too literary, a little naive and even biased, it shows that all the strategies of expeditious operation create one family. And just as in the family, they can live amicably together (although they do not have to); they can also, as each family member, lead their own, self-dependent life. But in more difficult moments, they always support each other.
Figure 1. Relations between TQM, Kaizen, Lean, Six Sigma, TOC, ISO 9001
TQM Kaizen
ISO 9001
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3. PRINCIPLES, METHODS AND TOOLS
The strategies of expeditious operations in themselves only have a certain potential. They gain operational power only in connection with rules, and above all tools and operational methods. However, they must be applied regularly and consistently, not only from time to time. According to a known old German proverb, “Uebung macht den Meister”, meaning “practice makes perfect”. This proverb refers to a concept, which is known as the daily practice. Practice is a set of activities performed regularly in certain situations. In a specific operation, practice is skills and knowledge gained through multiple and continued performance.
Following this trace, it can be said that a strategy, a rule, a method or a tool becomes a practice in a company, if it is regularly applied and is an element of daily routine of employees and managers. In such case it becomes a Practice of Expeditious Operation (PEO), if, thanks to its application, human performance efficiency, as well as operational and business efficiency of processes and a whole company are increased. Thanks to application of PEO, professional mastery of employees can be better used for company’s benefit.
Assigning a specific PEO to a particular group is a result of its properties [5,8]. As follows:
- strategy is distinguished by a certain general idea, concerns a whole company (is not related to any particular area of activity of a company), its realization requires rules, methods, tools and guidelines,
- rule – indicated that certain activities and attitudes are good for achieving intended results,
- method – is a determined methodology of operation, concerns particular area of operation of a company, its realization requires certain tools,
- tool – just as a method, it has determined methodology of operation, but it is usually simple and does not require use of other tools (tools are usually intuitive in use).
It should be underlined, that definite majority of tools were invented before popularization of the improvement concept, see Fig.2. Today, a given tool and method can be assigned to many concepts, similarly as a given concept is assigned to many methods and tools.
Figure 2. Evolution of chosen strategies, methods and tools of expeditious operation
Incubation time of strategies for expeditious operation
Basic Statistical Tools Design of Experiments
Pareto Principle PDCA Control Chart Sampling – quality control
Kanban FMEA Poka Yoke
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Relying on certain elaborations, it can be said that all concepts use all tools and methods. Indeed, there is a lot of truth in this statement. However, disputing how a given company, declaring that it applies TQM rules, can implement a specific tool (e.g. TPM) which is not an essence of TQM, is a discussion of purely academic character. On the other hand, saying that we use TPM in TQM is a certain infelicity. But if it helps thinking or acting towards improvement, it should be of no concern. 4. SYNERGY OF SEO AND
OCCUPATIONAL PROFICIENCY Tools and methods of Lean, Kaizen or Six Sigma are often used with an intention of improving products, operations and processes, which are, simply saying, designed in an incorrect way. Such a proceeding can hardly be named improvement, it is merely a form of repair. That is because the described concepts are not a cure for all or most of a company’s problems, as sometimes suggested by neophytes and specialists from consulting companies’, often really believing in it. In reality, these methods are just a support for design engineers, process engineers, salesmen, IT specialists, planners etc. That is because performing of daily duties relies on fundamental professional preparation, regarding basic activity of a company. Its success is dependent on professional knowledge and competences of employees.
Sometimes it resembles an approach of a tribal shaman (healer), who does not know fundamentals of human anatomy and physiology and still attempts to heal people. Nowadays, when companies aim at being “lean”
and friendly for their stakeholders (employees, society, environment), mere mastery in a given profession is not enough to achieve high operational expeditiousness of processes (higher than competitors). Today, operational expeditiousness means more than, e.g., in 70s of XXth century. In that time, it meant mostly supplying products with a competitive price (in the market economy; the command economy was ruled by different principles). Today, operational expeditiousness comprises also minimization of wastage, limiting influence on natural environment and creation of human- friendly environment. There is no way it can be achieved without extra competences. In a modern company, even someone of very high professional qualifications, a true master in operations regarding a given profession, must take care of the so-called soft competences, which are skills such as cooperation, time management, work organization, creativity, learning, communicating etc. It is a frequent case, when a brilliant specialist loses its market position with a worse one, but distinguished by soft competences. The soft competences – in comparison with the hard ones – are less dependent on knowledge. They depend highly on character, temper, attitude, openness for change, willingness for cooperation etc. They are gained through operations requiring creativity, teamwork, attempting endeavors with results dependent not only on knowledge and professional skills, but also on being open and flexible. The TQM, Kaizen, Lean, Six Sigma, Theory of Constraints together form a brilliant environment for its harmonious and synergic development, see Fig. 3.
Figure 3. Synergy of SEO
Synergy
Soft competences
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5. REFERENCES - LITERATURA [1] Boek M., Hamrol A.: Analysis of efficiency
of Lean Manufacturing and Six Sigma in a production enterprise, Management and Production Engineering Review – MPER, No. 3, 2012
[2] Cox J., Schleier J., Handbook: Theory of Constrains, McGraw Hill, 2010, New York.
[3] Deming W.E. Out of the crisis, The MIT Press1982, London
[4] Goldratt E.M.: The Goal, North River Press 2005, Great Barrington
[5] Hamrol A.: Strategies and practices of efficient production. Lean, Six Sigma and others, Scientific Publishing House (PAN). Warsaw 2015
[6] Hamrol A.: How political and economic circumstances can influence pursuits of excellence in quality management, TQM&BE, volume 2, 2011
[7] Oakland J.S.: Total Organizational
Excellence, Butterworth Heineman 2007 Oxford
[8] Starzynska B, Hamrol A.: Excellence toolbox: Decision support system for quality tools and techniques selection and application, Total Quality Management & Business Excellence, 2013, Vol. 24, No. 5.
Coresponding author: Adam HAMROL, prof. dr hab. in. Poznan University of Technology Department of Management and Production Engineering ul. Piotrowo 3, 60-965 Pozna tel.: +48 61 665 27 74
Rad je objavljen na Konferenciji „QUALITY 2017“, Neum 17-20 May 2017 The paper was published at the Conference “QUALITY 2017”, Neum 17-20 May 2017
Mašinstvo 2(14), 81 – 90, (2017) E. Dedi: ACADEMIC STAFF EVALUATION…
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ACADEMIC STAFF EVALUATION – OBJECTIVE MODEL
Enes Dedi University of Biha Kljune rijei: evaluacija, radna uspješnost, akademsko osoblje, visokoškolske ustanove Keywords: evaluation, job performance, academic staff, higher education Paper received: 16.04.2017. Paper accepted: 10.05.2017.
Rad sa konferencije REZIME Evaluacija radne uspješnosti akademskog osoblja predstavlja poseban izazov u visokoškolskom obrazovnom sistemu u Bosni i Hercegovini. Ustaljena praksa samopredstavljanja apsolutnog autoriteta na javnim visokoškolskim ustanovama je poela slabiti pojavom privatnih visokoškolskih ustanova na kojima su poslodavci traili rezultate, predstavljali svoja oekivanja, ali i zahtjeve studenata. Suoeni sa novim razvojem u ovoj oblasti, lanovi akademske zajednice se nalaze pred velikom nepoznanicom i strahuju da bi se primjenom raznih modela ustvari iskrivila slika njihovog doprinosa, vrijednosti uinka i zasluga, te shodno tome i ukinule ili problematizirale beneficije koje koriste. Ovaj rad daje detaljan pregled stanja, oekivanja i zahtjeva za ispravno postupanje, te predstavlja jedan objektivni model.
Conference paper
SUMMARY Academic staff evaluation poses a unique challenge in higher education system in Bosnia and Herzegovina. The established practice of self- representing the absolute authority in public higher education institutions attenuated by the emergence of private higher education institutions where the employers sought for the results, expressed their own, as well as students’ demands. Encountered with new development in this domain, the members of academic community are facing an unknown and are feared that the application of various models would in fact deteriorate the image of their contribution, the value of their results and credits, and consequently recall or query the benefits at their disposal. This paper provides a detailed overview, expectations and demands for proper practice, and represents an objective model to be used.
1. TERMINOLOŠKE DILEME EVALUACIJE
Vrjednovanje rezultata rada predstavlja neizostavnu aktivnost svake radne organizacije, bez obzira na vrstu poslova i djelatnosti kojima se bavi. Iako ocjenjivanje rada akademskog osoblja nije potpuno usvojena praksa, ono je postalo svakodnevnica i ovaj rad pokušava dati odgovore na kljune dileme vezane za ocjenjivanje radne uspješnosti akademskog osoblja. Potrebno je u uvodu istai da u našem obrazovnom sistemu, akademsko osoblje, s izuzetkom redovnih profesora, zakljuuje ugovore na odreeno vrijeme i produenje ugovora nije uslovljeno iskljuivo uspjehom u nastavnom procesu. Specifinosti visokog obrazovanja dodatno uslonjavaju ovaj proces, tako da je pored evaluacije nastavnog rada, potrebno uspostaviti sistem koji vrjednuje i istraivaki rad i publicistiku, administrativne
1. TERMINOLOGICAL EVALUATION DILEMMAS
Evaluation of performance results represents a required activity of every working organization, no matter what the type of business or work. Even though academic staff evaluation is not absolutely accepted practice, it has become a part of everyday life so this paper tries to answer the key dilemmas related to academic staff performance evaluation. It must be stressed in this introduction that in our educational system, academic staff, except for full-time professors, sign definite duration contracts and contract renewal is not related only to teaching success. Specific features of higher make this process even more complicated, so, apart from teaching evaluation, it is necessary to establish a system of evaluating research, publications, administration and wider
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aktivnosti, te doprinos razvoju društva u cjelini. Akademsko osoblje je svjesno potrebe evaluacije kvaliteta svoga rada, ali istovremeno s teškoom prihvataju modele evaluacije koji su drugaiji od njihove percepcije „bitnih“ karakteristika rada akademskog osoblja. Radna uspješnost, odnosno koncepti poput radnog uinka i rezultata rada su definisani iz nekoliko perspektiva. Mawoli i Abdullahi [1] predstavljaju više definicija kojima je zajednika odrednica da radna uspješnost predstavlja mjeru u kojoj zaposlenik ostvaruje postavljeni zadatak i koliko taj ostvareni zadatak doprinosi realizaciji organizacijskih ciljeva. Nadalje, ocjenjivanje performansi obino provodi samo direktno nadreeni, za razliku od evaluacija akademskog osoblja koje naješe sadre cjelokupnu sliku koju daju i studenti i radne kolege. Isto tako, fokus ocjenjivanja performansi je ogranien samo na opis radnog mjesta, dok se kod evaluacija akademskog osoblja, bez obzira na nivo i zvanje, vrjednuju najmanje tri razliita aspekta – nastava, istraivanje i administrativni poslovi. 2. O NASTAVNICIMA I EVALUACIJI
NASTAVNIKA Upravljanje uinkovitosti zaposlenika i njeno ocjenjivanje svoje porijeklo ima u industriji, a temeljna karakteristika je periodinost, koja u odreenim modelima sadri i definisanje i postavljanje ciljeva. Bush i Middlewood [2] navode da je formalna, periodina evaluacija nastavnog procesa u SAD uspostavljena 1970-ih, te su rezultati bili prikladni za administrativne poslove utvrivanja visina plaa i promocija osoblja, ali ne i za unaprijeenje nastavne prakse. Ovi autori takoer predstavljaju injenicu da je uloga nastavnika razliita, tako da je i ocjenjivanje uinkovitosti nastavnika kontekstualno i kulturološki uslovljeno. Kao primjer navode se obrazovni sistemi u Africi, Kini i u nekim Zapadnim crkvenim školama gdje je vjerovanje sastavni dio osvnovnih vrijednosti, te kao takvo kondicionira sistem evaluacije uinkovitosti. Obrazovanje je sve više regulirana oblast koja pored transparentnosti i odgovornosti namee zahtjev argumentirane i mjerljive pozitivne prakse rukovoenja. Svjedoimo konstantnom smanjenju raspoloivih finansijskih resursa u javnom sektoru, tako da su sve glasniji zahtjevi za efikasnijim korištenjem i uporedbom sa ostvarenim rezultatima. Iz svega proizilazi potreba za konstantnim unaprijeenjem metoda mjerenja radnog uinka i ostvarenih rezultata i ishoda.
contribution to society. Academic staff is aware of the need to evaluate the quality of their work, but at the same time, they have difficulties accepting an evaluation model different from their own perception of “relevant” academic staff features. Work efficiency, namely concepts of job performance and results are defined from several perspectives. Mawoli and Abdullahi [1] represent several definitions with a common feature depicted as a measure of accomplishment of defined tasks and how that tasks contributes to the overall organizational goals. Furthermore, performance evaluation is usually performed by only direct supervisor, while academic staff evaluation entails the entire image created by both students and colleagues. Moreover, the focus of performance evaluation is only on working position description, while academic staff evaluation, no matter what the level or title is, deals with at least different aspects – teaching, research and administrative duties. 2. ON TEACHERS AND TEACHER
EVALUATION Employee performance management and its evaluation were established in industry with periodicity as its basic feature, in some systems entailing goal setting as well. Bush and Middlewood [2] state that formal, periodic evaluation of teaching process in the USA was established in 1970s and the results were appropriate for administrative tasks like remuneration calculation and staff promotion, but not for teaching practice enhancements. These authors also portray the fact that teacher roles are different, so the evaluation of teacher performance is contextually and culturally conditioned. Educational systems in Africa, China and some western church schools, where belief is among basic values, are mentioned as the examples that condition performance evaluation systems. Education is more and more regulated profession that, apart from transparency and responsibility, requires the argumentative and measurable examples of positive leadership practices. We are witnessing the constant reduction in available funds in public financing schemes, so the demands for more efficient use and results comparison are becoming ever louder. All these make the need for continuous enhancements of performance and outcome evaluation methods more apparent.
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2.1. Ciljevi i funkcije evaluacije Ocjenjivanje i evaluacija nastavnika bi morala unaprijediti uenje, ili barem nastavu.[3] Stoga, unaprijeenje kvaliteta procesa uenja mora biti prisutno u bilo kojoj evaluaciji rada nastavnika. Proces evaluacije mora osigurati ostvarivanje eljenih ciljeva unutar organizacije. Iz perspektive menadmenta, sistem evaluacije radnog uinka postaje potpuno besmislen ako nema snagu rezultiranja odgovarajuim mjerama u interesu VŠU. Mnoge studije u sektoru visokog obrazovanja ukazuju na duboku podjelu u percepciji izmeu nastavnog osoblja i menadmenta u pitanjima profesionalne odgovornosti. Problem lei u tome što su sistemi evaluacije ili previše preskriptivni, oslanjaju se na brojke, ili su previše uopeni i neodreeni, kao npr. oekivanje da ocjenitelj da ocjenu od nezadovoljavajui do izuzetno, bez da se daju jasne smjernice šta te ocjene predstavljaju i na koji nain da se formiraju. Craftova [4] navodi dodatne razlike izmeu razvojne evaluacije, formativne, sumativne, evaluacije odgovornosti, kvalitativne i kvantitativne, te primjene otvorenog ili zatvorenog pristupa. Sistem evaluacije koji se koristi na VŠU istovremeno oblikuje radnu kulturu i kvalitet akademskih rezultata te institucije. Stoga je veoma bitno da VŠU koje ele poboljšati svoje rezultate u oblasti obrazovanja i uenja studenata moraju istovremeno razvijati sistem evaluacije nastavnog procesa.[5] Procesom evaluacije nastavnog procesa mogue je istovremeno doprinijeti unaprijeenju nastave, nagraditi izuzetne primjere, prilagoditi zadatke, zaštititi pojedince i ustanove, potvrditi proces izbora osoblja, zadovoljiti propise i zakone, unaprijediti procese odluivanja, postaviti osnovu za planiranje karijere, te doprinijeti radnoj atmosferi i motivisanju. Evaluacija takoer mora zadovoljiti potrebe profesionalnog razvoja nastavnika, te izbjei nesklad izmeu linih i prioriteta obrazovne ustanove. Evaluacija moe posluiti ne samo kao sredstvo identifikacije potreba, ve i za definisanje potrebnih koraka za ostvarenje tih potreba i usaglašenih ciljeva. Evaluacija treba rezultirati unaprijeenjem stanja i/ili oslobaanjem od onih koji ostvaruju prosjene ili ispodprosjene rezultate.
2.1. Goals and functions of evaluation Assessment and evaluation of teachers should enhance learning, or at least teaching.[3] Therefore, the enhancement of quality of learning process must be a part of any evaluation scheme used for teacher performance evaluation. The evaluation process must ensure the achievement of set goals within the organization. From the managerial perspective, the process of performance evaluation becomes absolutely useless if it cannot achieve defined goals relevant for a higher education institution. Many studies in higher education sector indicate wide divide in perception between academic staff and management, when it comes to professional responsibility. The problem lies in evaluation systems that are either too prescriptive and rely solely on numbers, or are too general and unspecified, e.g. they expect that evaluator should evaluate between unsatisfactory and exemplar, without clear guidelines what these evaluations represent and how should be formed. Craft [4] mentions additional differences between developmental evaluation, formative, summative, evaluation of responsibility, qualitative, quantitative and use of open or closed approach. Evaluation system used at HEI forms the institutional culture, as well as the quality of academic results of that institution. Therefore, it is crucial for institutions that want to improve their results in education and learning to develop the system of evaluation of educational process as well.[5] The process of evaluation of educational process provides for teaching enhancements, rewarding the exquisite examples, adjust tasks, protect individuals and institutions, confirm staff selection process, satisfy legal requirements, improve decision making processes, create foundation for career development and contribute to the overall working atmosphere and motivation. Evaluation must also satisfy needs for teacher professional development and avoid dissonance between personal and institutional priorities. The evaluation could serve not just as a tool for needs identification, but also as a tool for defining necessary steps towards realization of these needs and agreed objectives. It should result in improvements and/or getting rid of those that achieve average or under average results.
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2.2. Modeli evaluacije Radni uinak je multidimenzionalan koncept koji se sastoji od više vrsta ponašanja. Buller [6] predstavlja „Sveobuhvatni sistem evaluacije akademskog osoblja“ koji je razvio Raoul Arreola u saradnji sa Lawrence Aleamoni i usavršio 2007. godine. Znaaj ovakvog pristupa je u tome što smanjuje nivo subjektivnosti u procesu evaluacije akademskog osoblja. Osnovna karakteristika ovog modela je proces u osam koraka koji osigurava maksimalnu sveobuhvatnost i objektivnost evaluacije akademskog osoblja. Prvi korak zahtjeva da se definiše uzoran primjer akademskog osoblja. Drugi korak pretpostavlja da se odrede vrijednosti parametara uzornog modela akademskog osoblja. Trei korak je utvrivanje svojstava uzornog primjera akademskog osoblja. etvrti korak je utvrivanje teinskih faktora za svaku komponentu svojstva, na nain da se odrede prioriteti i teinski faktori svakog mjerljivog ponašanja. Petim korakom se definišu prikladni izvori informacija, odnosno naini praenja i mjerenja ovih ponašanja. Šestim korakom se odreuju teinski faktori izvora informacija, te se odreuju prioriteti i teinski faktori za svaki izvor informacija. U sedmom koraku se odreuje nain na koji e informacije biti prikupljane. Osmim korakom je predvieno upotpunjavanje sistema na nain da se prikupe informacije, analiziraju i izvjesti o rezultatima. Pa ipak, ovakav model nee dobiti podršku svih, posebice akademskog osoblja iz podruja humanistikih nauka, koji se generalno protive kvantifikaciji kojom se iskrivljuje stvarna slika kompleksnosti uloge akademskog osoblja. Türk [7] navodi da se evaluacija nastave prati kroz broj sati nastave i broj uspješnih kandidata u procesu mentorstva, prilagoeno na osnovu nivoa nastave i jezika. Takoer, u obzir se uzima broj publikacija u referentnom periodu, prilagoen na osnovu kvaliteta objavljene publikacije. Ocjena postignuta evaluacijom moe biti korigovana na osnovu kvalitativnih pokazatelja koji nisu zastupljeni u kvantitativnom mjerenju od strane direktno pretpostavljenog. Ranije je navedeno da je potrebno osigurati prihvaenost sistema evaluacije meu akademskim osobljem. Pa ipak, ovdje je nuno istai razlike utemeljene na kulturološkim osnovama. Odnos prema akademskom osoblju je rezultat odreenog društva i preovladavajue kulture.
2.2. Evaluation models Job performance is a multidimensional concept made of several types of behavior. Buller [6] represents “comprehensive faculty evaluation system” developed by Raoul Arreola and Laawrence Aleamoni and further improved in 2007. The importance of such an approach is in its reduction of subjectivity in academic staff evaluation process. The main feature of this model is the eight-step process that ensures maximal comprehensiveness and objectivity in the process of academic staff evaluation. The first step requires determination of academic staff role model. The second step assumes determination of parameter values of the role model. The third step is defining roles of the role model. The fourth step is determination of role features weights, in a way to define priorities and weights for every observable behavior. The fifth step should define appropriate data source, i.e. the ways to monitor and measure these behaviors. The sixth step defines weight factors for every information source. In the seventh step, one should define ways how information should be acquired. The eighth step assumes completion of the system by collecting information, analyzing it and reporting on the results. Nevertheless, such a model will not be accepted by all, especially by academic staff in Humanities that in general are against quantification which distorts the true and complex image of academic staff roles. Türk [7] states that evaluation of teaching is done through the number of lecture hours and successful mentoring of students, scaled to the level and language of instruction. Furthermore, the number of publications in reference period, scaled to the quality of publication, is also taken into account. The score achieved in the evaluation process might be adjusted according to qualitative indicators not present in quantitative measurements by direct superior. It was mentioned earlier that the acceptance of evaluation system among academic staff should be achieved. However, one must be aware of differences based on cultural differences. Attitudes towards academic staff are the results of certain societies and overwhelming cultures.
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Tako Bush i Middlewood [2] navode primjere Japana gdje je fokus na zajednici, a ne na pojedincu, te je kao takav, sistem evaluacije razliit u odnosu na Zapadno poimanje uloge pojedinca. Drugi primjer kulturološke razliitosti je evidentan u islamskim društvima gdje se nastavnik doivljava kao drugi otac, te se shodno tome i poštovanje i odnos prilagoava, tako da je detaljna evaluacija rada nastavnika, ne samo skoro nemogua, ve i antiislamska. Direktan primjer su medrese u Pakistanu gdje vjerska percepcija uslovaljava sve druge aktivnosti, pa tako i evaluacije rada akademskog osoblja. 2.3. Proces evaluacije Ocjenjivanje radne uspješnosti se bavi procesom praenja i evaluacije radne uspješnosti s ciljem identifikacije potreba za unaprijeenja, kao i rad sa zaposlenicima kako bi se poveala njihova efektivnost i maksimalno iskoristili njihova znanja i vještine. Pri tome, potrebna je odrednica sistemskog pristupa ovom pitanju, a u veim organizacijama obavezna je i strunost onih koji provode proces, kao i poznavanje radnog procesa i radnog mjesta, odnosno zahtjeva tog radnog mjesta. Buller [6] objašnjava pristup Greg Martina koji proces evaluacije nastavnog osoblja predstavlja u etiri osnovna koraka. Prvi korak je definisanje kriterija po kojima e akademsko osoblje biti evauirano. Drugi korak je uspostava jasnih standarda za svaki kriterij, odnosno precizno definisanje šta predstavlja oekivani kvalitet u nastavi, istraivanju i administrativnim poslovima. Trei korak je predstavljen odabirom indikatora koji odreuju nivo ostvarene uinkovitosti. etvrti korak je integracija ostalih relevantnih informacija u sistem godišnje evaluacije zaposlenika. Nuno je osigurati da proces evaluacije bude svima jasan i prihvaen, posebno zbog toga što u ekstremnoj situaciji administracija ustanove moe otpustiti lana akademskog osoblja koji nikada nee priznati ili izjaviti da je ostao bez posla zbog lošeg rada ili nekompetentnosti. Za odranje morala u ustanovi, potrebno je da ostali zaposlenici budu upoznati sa ovakvom odlukom i razlozima koji su utemeljeni na pedagoškim standardima, normama i vrijednostima ustanove, kao i da vide da se pravino postupa.[3]
Bush and Middlewood [2] mention the examples of Japan where cultural focus is on the community as such, not the individual, so the evaluation system as well, is rather different when compared to Western comprehension of the role of an individual. Another example of cultural differences is evident in Muslim societies where teacher is seen as another father, so the respect and attitude toward the teacher are adjusted accordingly. Detailed evaluation of teacher performance in such context is, not just almost impossible, but also anti-Islamic. Direct examples are madrasas in Pakistan where religious perception precondition all other activities, including academic staff performance evaluations. 2.3. Evaluation process Job performance evaluation is about monitoring and evaluating performance with an objective to identify the needs for improvements, as well as to work with employees in order to increase their efficiency and maximize the use of their knowledge and skills. Therefore, systematic approach is needed and in larger organizations, also the expertise of those managing the process, as well as knowledge of work processes, work postions and demands for those positions. Buller [6] explains Greg Martin’s approach which presented academic staff evaluation in four basic steps. The first step is defining academic staff evaluation criteria. The second step is the establishment of clear standards for each criterion, i.e. precise definition of what is anticipated quality in teaching, research and administrative duties. In the third step, there is selection of indictors that define the level of accomplished effectiveness. The fourth step is integration of all other relevant information in the system of annual employee evaluation. It must be assured that the evaluation process is clear to and accepted by all participants, especially because in the extreme cases, the institution’s administration might fire an academic staff member that will never admit or state that she lost academic job due to poor performance or incompetence. In order to maintain morale in the institution, it is crucial that all the employees are familiar with such a decision and reasons based on the pedagogical standards, norms and institutional values, and to see fair treatment. [3]
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Literatura o evaluaciji nastavnog osoblja predstavlja ope metode evaluacije poput intervjua sa nastavnicima, testova kompetencija, indirektnog mjerenja, observacija na nastavi, evaluacija od strane studenata, evaluacija kolega, uspjeha studenata, i samoevaluacija akademskog osoblja. 2.4. Elementi evaluacije Praktian problem primjene bilo kojeg modela evaluacije predstavlja odabir broja kriterija, odnosno indikatora na osnovu kojih se vrši evaluacija. Opepoznato je pravilo da se sa što više indikatora moe donijeti detaljnija i preciznija evaluacija. Pa ipak, statistiki pokazatelji, odnosno indikatori, trebaju doprinijeti evaluaciji a ne zamijeniti je. [8] Na osnovu definisanih poslova lanova akademskog osoblja, elementi evaluacije moraju minimalno obuhvatiti nastavu, istraivaki rad i administrativne poslove. Iako je istraivaki rad po mnogo emu drugaiji od klasinog „proizvoda“, potreba za mjerenjem kvaliteta i poreenjem sa drugima je prisutna. Kod istraivanja se mjere i porede objavljeni radovi, napisane knjige, izlaganja na konferencijama i sl. tako da su ove publikacije ustvari fokus evaluacija. Jedan od pristupa je broj citiranja pri emu se kvantificiraju pokazatelji kvaliteta istraivakog rada, u pogledu same publikacije i primjenjenih indeksa. Drugi primjer je brojanje patenta, ali i ovdje je jasno da imamo velike probleme. Trea mogunost pretpostavlja uvid u kvalitet istraivanja, uzimajui za primjer Eigenfactor, H-indeks, ISI impakt faktor ili SCOPUS-ov normalizirani impakt po lanku kao validnu mjeru kvaliteta istraivakog rada. Pored ovih pomenutih indeksa, u upotrebi je i veliki broj drugih, ukljuujui Kineski indeks u društvenim naukama, Azijski nauni citatni indeks i Indijski citatni indeks. Iako se još uvijek raspravlja o tome da li i u kolikoj mjeri studenti treba ili mogu da ocjenjuju svoje nastavnike, ova praksa je prihvaena i prisutna u obrazovnim sistemima visokog obrazovanja i neizostavan je segment svake ozbiljne analize kvaliteta rada na visokoškolskoj ustanovi. Studentske evaluacije se primarno tiu evaluacije nastave, te kao takve trebaju biti ispravno percipirane kao indikator stanja u toj sferi. Ni u kojem sluaju ne bi smjele biti iskljuivi pokazatelj kvaliteta rada akademskog osoblja, posebno iz razloga što je evaluacija obojena karakterom nastavnika.[7]
Literature on academic staff evaluation presents general evaluation methods like teacher interviews, competence tests, indirect measurements, teaching observations, student evaluations, peer evaluations, students’ results and academic staff self-evaluation. 2.4. Evaluation elements A practical problem with any evaluation is selecting the number of criteria, i.e. indicators for evaluation. A generally accepted rule is the more criteria, the more detailed and precise evaluation will be. However, statistical indicators should contribute to the evaluation and not replace it. [8] According to the defined set of duties of academic staff, evaluation elements must entail at least teaching, research and administration. Even though research activities are in many aspects different from classical “product”, there is also need to measure and compare the results with others. In research, published papers, written books, conference speeches etc. are measured and compared, so these publications actually become the focus of evaluation. One of the approaches takes into account the number of citations where research quality indicators are quantified in terms of publication themselves and applied indices. Another example might be counting patents, but there are serious problems with such an approach too. The third possibility assumes the insight into the research quality by taking Eigen Factor, H-index, ISI impact factor or SCOPUS normalized impact per paper as a valid measure of the quality of research. Apart from these indices, there are many other indices in use, including Chinese Social Science Citation Index, Asian Science Citation Index and Indian Citation Index. Even though there are still discussions whether and how students should and could evaluate teachers, the practice is already accepted and present in higher education systems and mandatory aspect of any serious analysis of quality at HEI. Student evaluations are primarily related to teaching and should be treated properly as an indicator in this sphere. In any case, student evaluations should not be the only indicator of quality of work of academic staff, especially because the evaluation is colored by teacher’s character.[7]
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3. PREDSTAVLJANJE OBJEKTIVNOG MODELA EVALUACIJE
Objektivni model ocjenjivanja radne uspješnosti akademskog osoblja predstavljen je holistikim pristupom evaluaciji akademskog osoblja, tako da obuhvata obrazovne aktivnosti, nauno- istraivaki rad i nenastavne obaveze. Za svaku od ovih osnovnih oblasti napravljene su detaljnije klasifikacije, i to na nain da je svo akademsko osoblje moglo davati svoje prijedloge za izmjene i dodavanja stavki, kao i bodovne vrijednosti predloenog sistema evaluacije. Proces definisanja kategorija, stavki u kategorijama i bodovnih vrijednosti za svaku stavku je trajao tri mjeseca i tek nakon iscrpnih rasprava usvojen je okvir i sistem evaluacije. Sistem je definirao da svaki lan akademskog osoblja popunjava samoevaluacijsku tabelu, za svaki od predefinisanih elemenata, te da prikupi i dostavi dokaze centralnoj administrativnoj slubi univerziteta. Sistemom je predvieno da jedino rektor univerziteta nee biti evaluiran. Popunjavanje samoevaluacijske tabele pretpostavlja unošenje brojane vrijednosti i mnoenje sa bodovnom vrijednosti za svaku stavku. U nekim poljima je bilo potrebno unijeti i dodatne informacije, poput autora, naziva radova i urnala i sl. Za ovo je korištena elektronska forma koja je automatski vršila izraune pojedinanih i ukupnih vrijednosti. Direktni nadreeni lana akademskog osoblja su imali mogunost davanja komentara i opaanja o radu lana akademskog osoblja, ali nisu imali mogunost mijenjanja rezultata postignutih u ovom sistemu evaluacije. Primjenjen je sistem ocjenjivanja od pet definisanih kategorija. Ustanova je definirala svoj prihvatljivi prag kvaliteta i sve koji ga ostvare ocijenila pozitivnom, zadovoljavajuom ocjenom. Kako bi se ostvario cilj dodatnog motivisanja i ukazivanja na eljena i oekivana ponašanja i prakse, istaknuto je najboljih 10% i dodijeljena su im odreena priznanja. Na ovaj nain se ostvario i cilj evaluacije koja doprinosi razvoju nastavnika. Ustanova je u stanju definisanjem svoga praga i faktorizacijom bodovnih skala usmjeravati akademsko osoblje u eljenom pravcu i na odgovarajui nain. Oblast nauno-istraivakog rada je detaljnije podijeljena na klasu Publikacije, radovi i reference i klasu Projekti, patenti i nagrade. Za svaku posebnu klasu je odreen teinski faktor decimalnog karaktera, po 0,20.
3. PRESENTING AN OBJECTIVE EVALUATION MODEL
An objective performance evaluation model is presented through a holistic approach to academic staff evaluation. Therefore, it includes educational activities, scientific and research work and administrative duties. For every of these three basic areas, detailed classifications are prepared in a way that academic staff could give their proposals for changes and additions of particular features and numerical values within the system. The process of categorical definitions, items in each category and numerical values for each item lasted for three months and just after the detailed discussions was adopted as a framework and evaluation system. The system defined that every academic staff member should fill-in self- evaluation table, for every pre-defined item and to provide evidence to central university administration service. The system assumed that only Rector is exempt from this evaluation scheme. Filling-in the self-evaluation table assumed entering numerical values and points multiplication for each item. For some items, it was necessary to provide additional information, like authors, journal and paper titles etc. Electronic form was used so the points were calculated automatically for every single item, but the general score too. Direct line superiors could provide comments and notes on academic staff member work, but could not alter the scores calculated in the process. The evaluation system made of five pre-defined categories was used. The institution defined its acceptable threshold level of quality and everyone who achieved it was evaluated with a positive, satisfactory score. In order to achieve additional motivational goal and to indicate desirable and expected behaviors and practices, top 10% were identified and rewards were given to them. By doing this, a contribution to teacher development was secured as an evaluation goal. The institution is capable to, through defining its threshold level and factorization of scoring scales, direct academic staff in a desirable direction and in proper way. The scientific-research area was further divided in two classes – Publications, papers and references, and Projects, patents and awards. Each class had its decimal weight factor and in this particular case it was the same for both these classes – 0.20.
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Klasa Publikacije, radovi i reference je bila podijeljena na 11 stavki, sa dodatnim podjelama, ovisno od specifinosti svake stavke. Svaka pojedina stavka je precizno opisana tako da ne postoji mogunost pogrešnog svrstavanja rezultata rada akademskog osoblja, i za svaku su dodijeljeni bodovi. Raspon bodova je od 2 do 100, a za odreene stavke je definisan prihvatljivi maksimum, bilo bodovno, bilo koliinski. Dodatni koeficijent koji je korišten u ovoj oblasti je broj autora i faktorisanje je izvršeno na 4 nivoa, sa vrijednostima od 0,4 do 1. Klasa Projekti, patenti i nagrade je podijeljena na 4 stavke sa detaljnijim podjelama. Raspon bodova je odreen od 10 do 150. Oblast obrazovnih aktivnosti je podijeljena na tri klase: Predmeti, Konsultacije i Studentska anketa. Teinski faktor za Predmete je 0,20, dok je za druge dvije klase 0,10. U okviru klase Predmeti, predvieno je da se evaluacijom napravi distinkcija izmeu sata predavanja na dodiplomskom i diplomskom studiju. Korišteni omjer je za 50% vea bodovna vrijednost sata na diplomskom studiju. Klasa Konsultacije je podijeljena na 5 stavki a raspon bodova je od 2 do 15. Klasa Studentska anketa predstavlja rezultate anketiranja studenata koji se izraavaju bodovnim vrijednostima na skali od 1 do 5 tako da u ukupnom rezultatu evaluacije akademskog osoblja predstavlja istu brojanu vrijednost. Oblast nenastavnih dunosti je definisana kroz 10 stavki sa detaljnijim podjelama a raspon bodova je od 2 do 150. Ovdje su definisane stavke administrativnih zadataka sa navedenim administrativnim i rukovodnim funkcijama na univerzitetu, zatim lanstva u tijelima univerziteta, ueše u promotivnim aktivnostima i organizacija skupova. Takoer je evaluiran i širi doprinos zajednici kroz stavke voenja strunih udruenja, strunih aktivnosti izvan univerziteta i medijskog prisustva. Visokoškolska ustanova moe definisati obim eljenih rezultata svojih uposlenika u svim kategorijama, izraunati bodovne vrijednosti i iste definisati kao normu. Ovo normiranje je mogue uraditi na nivou svake od stavki korištenog obrasca, ali je bolje definisati bodovnu vrijednost i limite u pojedinim stavkama kako bi se osigurala raznolikost i distribucija nastavnikog djelovanja u podrujima na osnovu linih preferenci, tako da bi oekivanja od lana akademskog osoblja bila da ostvari:
Publications, papers and references class had eleven sections with additional item divisions, depending on specific features of every section. Every single item was described in details, so there was no possibility to misclassify one’s results, and every item had its numerical value. Item values were spread between 2 and 100, and certain items had its quantitative limitation, either in terms of maximum acceptable points or occurrences. Additional factor used in this class was the number of authors and factoring was done in four categories with values between 0.4 and 1. Projects, patents and awards class had four sections with further item divisions. Item values were between 10 and 150. Educational activities area was further divided into three classes – Courses, Consultations and Student evaluation. Weight factor for Courses was 0.2., and for other two classes was 0.10. Courses class anticipated distinction between lecture hours in courses taught at undergraduate and postgraduate levels. The used ratio was 50% higher values for lecture hour in postgraduate courses. Consultations class was divided in five sections with item values between 2 and 15. Student evaluation class was represented by the results of student evaluations on a scale from 1 to 5 and in this system it kept the same values in overall evaluation. Administrative duties area was present through 10 classes with detailed items and item values were between 2 and 150. It included administrative tasks related to administrative and managerial functions at university, memberships in university bodies and committees, participation in promotional activities and events organizations. A wider contribution to society was evaluated in this area through items like running professional associations and professional activities outside the university and media presence. A higher education institution could define the volume of desirable results for its employees in all areas and classes, calculate numerical values and define them as a norm. This norm-setting could be done at the level of a single item, but it is a way better to do it at area and/or class levels in order to provide for certain differences and distribution of academic staff activities in the areas of their personal preferences, so there could be an anticipation from a member of academic staff to achieve:
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o Publikacije, radovi i reference – 120 bodova,
o Projekti, patenti i nagrade – 90 bodova, o Obrazovne aktivnosti – 50 bodova, o Administrativne dunosti – 20 bodova,
svi bodovi bez faktorisanja. Ovaj primjer predstavlja optimalan pristup izmeu potpune akademske slobode i potpunog definisanja ciljanih rezultata ustanove. Ovo optimalno rješenje daje odreeni nivo slobode svakom lanu akademskog osoblja i istovremeno osigurava ostvarenje eljenih ciljeva ustanove. Nadalje, modifikacijom ovih vrijednosti, ustanova šalje jasnu poruku svom akademskom osoblju u kojim podrujima oekuje vee rezultate i šta je fokus ustanove za narednu godinu.
o Publications, papers and references – 120 points,
o Projects, patents and awards – 90 points, o Educational activities – 50 points, o Administrative duties – 20 points, prior
to factorization. This example represents an optimal approach between total academic freedom and total control of institutional results. This optimal solution gives certain level of freedom to every member of academic staff and at the same time provides for acquisition of institutional goals. Furthermore, by modifying the item values and factors, the institution is sending a clear message to its academic staff about the institutional focus in the following year, about its expectations and expected staff results in certain areas.
5. REFERENCES - LITERATURA [1] Mawoli, M. A.; Abdullahi, Y. B.: An
Evaluation of Staff Motivation, Dissatisfaction and Job Performance in an Academic Setting, Australian Journal of Business and Management Research, ISSN 1839-0846, Vol. 1, No. 9, December 2011, pp. 1-13
[2] Bush, T.; Middlewood, D.: Leading and Managing People in Education, SAGE Publications London, 2005.
[3] Mercer, J.: Appraising higher education faculty in the Middle East, Management in Education, ISSN 0892-0206, Vol. 20, No. 1, February 2006, pp. 17-26
[4] Craft, A.: Continuing Professional Development: a practical guide for teachers and schools, RoutledgeFalmer London, 2000.
[5] Toch, T.; Rothman, R.: Rush to Judgment: Teacher Evaluation in Public Education. Education Sector Reports, Education Sector Washington, D.C., 2008.
[6] Buller, J. L.: Best Practices in Faculty Evaluation: A Practical Guide for Academic Leaders, Jossey-Bass San Francisco, 2012.
[7] Türk, K.: Performance Management of Academic Staff and its Effectiveness to Teaching and Research – Based on the Example of Estonian Universities, Trames Journal of the Humanities and Social Sciences, ISSN 1736-7514, Vol. 20 , No. 1, March 2016, pp. 17-36
[8] Türk, K.: Performance Appraisal in the University of Tartu, EBS Review, ISSN 1406-0264, No. 17, Autumn 2003, pp. 143-150
Coresponding author: Enes Dedi University of Biha Email: [email protected] Phone: +387 61 105 722
Rad je objavljen na Konferenciji „QUALITY 2017“, Neum 17-20 May 2017 The paper was published at the Conference “QUALITY 2017”, Neum 17-20 May 2017
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Mašinstvo 2(14), 91 – 104, (2017) D. Vidakovi et all: MAINTENANCE AND EFFECT OF…
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MAINTENANCE AND EFFECT OF MACHINES WORKED ON CONSTRUCTION SITE
Drislav Vidakovi1, Zlatko Lackovi1, Milan Ivanovi2 1University J. J. Strossmayer in Osijek, Faculty of Civil Engineering, Osijek 2Panon – Institute for strategic studies, Osijek Kljune rijei: graevinski strojevi troškovi, odravanje, planiranje, uinak Keywords: construction machinery, costs, maintenance, planning, effect Paper received: 10.04.2017. Paper accepted: 16.06.2017.
Rad sa konferencije REZIME U radu je pojašnjeno znaenje i vanost uinka graevinskih strojeva obzirom na specifinosti njihove uporabe. Opisani su naini organizacije aktivnosti odravanja strojeva na gradilištima i ukazano je na utjecaj koji to ima na njihov uinak. Naglašene su mogunosti unaprjeenja postojee prakse izvoaa graevinskih radova i istaknuta je potreba praenja ostvarenih uinaka i izrade i kontinuiranog auriranja internih baza podataka koji su podloga za planiranje i odluivanje o realizaciji mehaniziranih radova.
Conference papaer
SUMMARY The paper explained meaning and importance of the impact of construction machinery due to the specifics of their use. Describes how organization of maintenance activities of machines on construction sites and points to the impact this has on their performance. Accent was placed on possibilities of improving existing practice of building contractors and emphasized need for monitoring of achieved results, development and continuous updating of internal databases which are basis for planning and decision-making on implementation of mechanized work.
1. UVOD – SPECIFINOSTI UPORABE I ODRAVANJA STROJEVA NA GRADILIŠTIMA
Strojno izvoeni procesi esto su kritini za rokove i imaju veliko ueše u realizaciji graevinskih projekata, pogotovo kod niskogradnje i novogradnje (najviše za zemljane i betonske radove). Graevinska mehanizacija ima niz bitnih posebnosti u odnosu na uporabu i odravanje strojeva u industrijskim pogonima, a postoje i izvjesne slinosti sa strojevima u nekim drugim djelatnostima (npr. rudarstvu, šumarstvu i brodogradnji). Uporabu strojeva na gradilištima najviše karakterizira: • razliite karakteristike obavljanih poslova
tijekom uporabnog vijeka i promjenjivi uvjeti rada (svaki projekt je jedinstven);
• rad na radnim mjestima privremenog karaktera (promjena mjesta rada – od gradilišta do gradilišta, a i na jednom gradilištu esto više mjesta rada);
1. SPECIFICS OF USE AND MAINTENANCE OF MACHINES WORKED ON CONSTRUCTION SITES
Machine performed processes are often critical for deadlines and have a lot participation in implementation of construction projects, especially in engineering and new construction (up by earth and concrete works). Construction machinery has a number of important special features in relation to use and maintenance of machines in industrial plants, and there are certain similarities with machines in other industries (e.g. mining, forestry and shipbuilding). Usage of machines on building sites most is characterized by: • Various characteristics of completed tasks
over lifetime of a variable operating conditions (each project is unique);
• Work in workplaces temporary (change of work - from site to site, and at one site often more places of work);
Mašinstvo 2(14), 91 – 104, (2017) D. Vidakovi et all: MAINTENANCE AND EFFECT OF…
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• korištenje strojeva koji nisu uvijek optimalni izbor za odreenu vrstu radnih zadataka (jer se za postojeu koliinu rada ne isplati dovoditi drugi stroj);
• rad preteito na otvorenom prostoru (izloenost razliitim vremenskim nepogodama);
• neujednaenost koliina za realizaciju tijekom dueg vremena rada (esto i prekidi u radu);
• dislociranost mjesta izvoenja radova od centralnog mjesta za smještaj strojeva i shodno tome potreba za transportom na svako gradilište (nekada iziskuje montau i demontau) i organizacija aktivnosti odravanja strojeva na svakom gradilištu.
Za pouzdano planiranje troškova radova i za vremensko planiranje realizacije neophodno je poznavanje uinka strojeva koji se namjeravaju koristiti, i to uinka u konkretnim gradilišnim uvjetima rada. Jedinini troškovi rada strojeva su direktni troškovi i izraunavaju se u jedininoj analizi cijena kao umnoak koštanja sata rada odreenog stroja (koliko košta izvoaa radova) i normativa vremena, koji treba biti veliina obrnuto proporcionalna prosjenom ostvarenom uinku. Trajanje svake aktivnosti izraeno u radnim danima deterministiki se izraunava kao kvocijent umno&s

godina (volume) 14 broj (number) 2, april - juni (april

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