development of design for manufacturing

iDECON 2010 – International Conference on Design and Concurrent Engineering Universiti Teknikal Malaysia Melaka (UTeM) 20-21 September 2010

Development of Design for Manufacturing Assembly (DFMA) Software in Bahasa Melayu

Jum’Azulhisham A.S.1, Khairul Akmal S 2, Humaizi A3, Rosdzimin4

1Electrical, Electronics & Automation Section, Universiti Kuala Lumpur Malaysian Spanish Institute, Lot 13 – 16 Kulim Hi-Tech Park, 09000 Kulim, Kedah, Malaysia

Phone: +604-403 5219, Fax: +604-403 5201, Email: [email protected]

2 Mechanical Section, Universiti Kuala Lumpur Malaysian Spanish Institute, Lot 13 – 16 Kulim Hi-Tech Park, 09000 Kulim, Kedah, Malaysia


3 Pusat Pengajian Kejuruteraan Pembuatan, Universiti Malaysia Perlis, Kampus Ulu Pauh, 02600 Arau, Perlis, Malaysia


4 Jabatan Kejuruteraan Mekanikal Fakulti Kejuruteraan, Universiti Pertahanan Nasional Malaysia, Kem Sungai Besi, 57000, Kuala Lumpur

Phone: +603-90513400/4539/4509, Fax: +603-90513472, Email: [email protected]

The purpose of this paper is to present a new DFMA software that is created in Bahasa Melayu. The software was developed to assist in teaching the subject Design for Manufacture and Assembly for undergraduate students. The software is created using Visual Basic and MySQL. The software is based on Boothroyd Dewhurst DFMA methodology. Currently, teaching this subject uses manual procedure which is time consuming but it helps to strengthen the foundation of Boothroyd Dewhurst method. The software saves up to 97% of the time needed for manual procedure. This software is developed in Bahasa Melayu to differentiate it from the official Boothroyd Dewhurst software and any other software related. Even though the contents are in Malay, there are also English translation as most terms are familiar in English. Since the university had yet to obtain Boothroyd Dewhurst software, the author refer its content with the promo version of the original Boothroyd Dewhurst software that was supplied by vendors.

Keywords – DFMA, Visual Basic, MySQL, Boothroyd Dewhurst, Concurrent Engineering.

I. INTRODUCTION

The term “DFMA” comes with the combination of DFA (Design for Assembly) and DFM (Design of Manufacturing). The basic concept of it is that the design engineers apply the DFMA paradigm or software to analyze the manufacturing and assembly problems at the early design stage. By this means, all of considerations about the factors that affect the final outputs occur as early as possible in the design cycle. The extra time spent in the early design stage is much less the time that will be spent in the repeatedly redesign. The cost will be reduced when designer uses DFMA software [1,6]. This will also affected the increase of quality and efficiency of the whole

processes and manpower [2] and also improve manufacturing processes and assembly [15].

There are a few methods of DFMA available such as Boothryd Dewhurst, Hitachi Assemblability and Lucas-Hull. The focus of the software is Boothryd Dewhurst method [14].

Design for Manufacture and Assembly requires skill

and ability to understand technical drawings, part characteristics, parts insertion, part degrees of freedom and part handling [12]. It requires special ability and time consume to understand these method. Not all Malaysian manufacture able to use DFMA in their product design development especially small and medium industries. The cost of having such method requires high investment especially to buy appropriate imported software which costs more than RM20,000 to RM25,000 per license per computer exclude training. The other reason of this problem is the degree of understanding English language of some designer is low. This is due to their educational background used to apply Malay language as their technical language.

The software developed by Boothroyd Dewhurst is

compact. It seems easy to apply with user friendly’s graphical icons but it produce complicated maneuver along the screen and not in sequence. This may have difficulties for the designers in applying the knowledge and takes time to get use of it. Besides that, the designer requires more time in order to analyze parts of an assembly and sometimes required days to complete the analysis.


To date, many higher institutions use Boothroyd

Dewhurst DFMA software in the relevant subjects. However the institution has not yet acquires the software. The teaching method is done manually. The student uses pen, pencils and papers to sketch and make analysis. Therefore it is difficult to do Design for Manufacture and Assembly manually and takes some times to understand it. Suggestion to overcome this problem is to develop DFMA software in Bahasa Melayu which is presented in this paper.

In this software, users will not see any calculations and

command. User will select appropriate instructions, answering questions and obtain the results in terms of efficiencies of the design, efficiency or redesign parts, suggested material selection and suggested manufacturing process to be done.

The aim of this project is to develop DFMA Software in

Bahasa Melayu using Boothroyd Dewhurst methodology. We measure time taken for analysis to compare manual analysis method with the DFMA Software in Bahasa Melayu. The effectiveness of DFMA Software compare with DFMA method manually are also measured.

Visual Basic is developed based on the BASIC

Programming language [3,5]. The use of Visual Basic can be upgraded into web-based as part of further improvement [4, 10].

The authors claim that the software development takes

almost a year to build. The development consists of identifying types of software and database can be used which can be integrated with each other. Modifications of software design are done in order to reduce time of inserting appropriate data. Testing the software was done by the end user. Identify any area for improvement in the software. Lastly, survey questions were distributed to those who test the software to facilitate their views on the software for further studies.

II. Software Architecture

The software development consists of 2 parts. The programming used powerful features such as graphical user interface (GUI), object-oriented features, error handling structured programming and etc. It eases programmer in the software development [1]. The software requires database system in order to match a series of materials and processes. The database also useful in terms of applying specific computations to obtain efficiency. At the end of software development, testing procedure was made. The test conducted in order to compare the application of DFMA in manual method against DFMA

software applied by a number of students. This reflects their capability of understanding both languages engineering English and technical Malay language in applying DFMA analysis. The analysis employs a number of students who have good understanding in DFMA analysis Boothroyd Dewhurst methodology. A number of sub-assembly parts of 6 products were analyzed. The variance of pasts given to be analyzed proves their ability to understand DFMA analysis. Time measurement was taken for conventional DFMA analysis and analysis done using DFMA Software in Bahasa Melayu. This response to their ability to understand engineering English terms and translate it to technical Malay words. In order to gain feedback from the user, questionnaires were distributed. The questions consists of how the software solve design problems, the ability of technical language understanding, steps to insert data to the software, further training requirement, time comparison of both manual procedure and using software, requirement of understanding tables, ergonomics & user friendly and a few open ended questions which related to further improvement.

Figure 1: A flow chart of DFMA Software in Bahasa Melayu.

Phase 1

Phase 2

Start

Literature review on DFMA and related

Software development using Visual Basic &

Study the appropriate software to be use

Modification of the software design to ease

Software application testing to the students

Discussion and Conclusion

Improvement

End


A. Development of DFMA Software In Bahasa Melayu

The software developments consist of developing of two major forms namely, Design for Manufacture (DFM) form and Design for Assembly (DFA) form in Visual Basic. Visual Basic is a programming language based on Microsoft Windows. It is created in Integrated Development Environment (IDE) which permits the programmer to construct, run and debug its programs handily [1].

B. DFA form development

All essential element required in DFA were allocated in the software in appropriate sequence. This includes the general information of parts, rotation symmetrical, manual handling and manual insertion. The DFA form consists of two major sections. The first section is the raw material selection. Choosing the right material is the foundation of a good design. The second section is the machines and processes used to work the raw material. The right process is essential for creating finished parts that will meet the design requirements [6]. The use of Command Buttons, ComboBox and Option Buttons in Visual Basic ease the programmer in entering commands. The user require to click related information rather than spending more time to type.

Figure 2. DFA in Bahasa Melayu

C. DFM form development

The Forms Layout window were designed in such way to ease students in following steps as same as taught in their lecture. The Form Layout window consists of an image representing the screen and the form’s relative location on the computer screen. This facilitates students

understanding steps without having problem in maneuvering the screen, calculations to be made and miss match table rows and columns. The use of Operator Precedence in Visual Basic by applying arithmetic expressions in a sequence determined by rules similar to those followed in algebra. This is important in computing some simple application by entering numbers and automatically results will appear without ask to calculate. This shortened user time taken to make any computation. Based on the Shape Generation Capabilities of Processes table, General Shape Attributes have been appointed in order to select the appropriate material with selected attributes in form of hardware command. When some attributes were selected by the user, MySQL will compile related materials and prioritized accordingly before displaying it. The overlapped or same materials will not shown repeatedly and only display the most selected parts. This will assure user to select the most appropriate process to be done. The same process occurred in selecting process. This will reduce time to refer the tables.

Figure 3. DFM in Bahasa Melayu

D. Database development

A database is a collection of data that is organized so that its contents can easily be accessed, managed, and updated. Database is used in DFA in order to repeat command where parts to be assembled must be analyzed and recorded. It is a waste to develop software that requires huge space in order to do repeating command [16]

MySQL is used as a database to analyze manufacturing processes and material used in DFM and database for parts assembled. The development was made based on Design Rules for Assembly-oriented Product Design [13]. The correlations of these two analyses were formulated in order


to choose a number of processes and materials highly recommended for manufacture. The database also being used in DFA to formulate Operational Time, Operational Costs and efficiency before and after improvement made.

Table 1. DFM database using MySQL

In DFA the calculation used is simple where programmer has to calculate value of part orientation α and β symmetry. α and β is important to determine manual handling options.

α + β (1) where,

α symmetry is the largest angle a part would have to be turned about an axis perpendicular to the insertion axis.

Β symmetry is the largest angle the part would have to be rotated about the insertion axis for mating Operation Time of each part

Operation Time = number of item x (manual insert time + manual handling time) (2) Assembly Costs (CM) proportional to TM by a factor that accounts for wage rate and overheads.

CM = (RM/sec X 104) (3) Assembly Time, TM is determined by summing the handling and insertion times. TM=N x (HT +IT) (4) Where;

N= the number of items the operation is carried out

HT = Manual Handling Time / part IT = Manual Insertion Time / code

The Assembly Efficiency. 3 x (Σ estimation Minimum Time / Σ Operation Time) (5)

Estimated Assembly Time. EM is defined as the ideal assembly time divided by the estimated assembly time.

(6)

All calculations were not displayed on the screen but embedded in MySQL database. The only numbers appear and displayed on the main software is the results.

III. RESULTS AND DISCUSSION

The analysis consists of two tests conducted in terms of finding differences between manual methods of DFMA and by using software which have been developed. This also includes the comprehending of technical Malay Language compare with Technical English which they used in the Engineering field. A number of 6 parts with 3 sub-assemblies were identified and tested by 20 students. This requires 16 parts to be analyzed. The reason only 3 sub-assemblies were used in the analysis is due to time constrain to analyze all parts. The higher number of sub-assemblies to be analyze the higher time required to finish the analysis.

Six parts related in this analysis are shown in table

below: Table 2. Parts and sub-assembly used in the analysis

Sub-assemblies

Pa

rts

Mouse Top cover

Bottom Cover

Clicker

Marker Pen Cap Body Ink stick

Milk Container Kettle Pin Cover Cord

Grip Eye Glasses frame Lens Side

frame Plug Head

cover Pin Switch

For preliminary, the parts are tested to analyze

Design for Assembly (DFA) in two conditions. Times were taken to differentiate conventional method and software application. The results were taken based on average time taken to finish up the analysis of parts given.


Table 3. Results of DFA using conventional method

Total average time taken 20 students to analyze all

18 components is approximately 3.92 hours which nearly 4 hours.

Table 4. Results of DFA using DFMA Software in Bahasa Melayu Embeded in My SQL

Table 5. Overall Results of DFA using DFMA software in Bahasa Melayu

Time taken for DFMA Software in Bahasa Melayu

is incredibly good. It takes 6.23 minutes to analyze all 16 parts.

As a comparison of DFMA manual analysis with

DFMA Software in Bahasa Melayu authors have found there are significant differences between these two methods. Time variance shows 3.8 hours difference. To show the efficiency of the analysis is done. This shows the percentage differences between manual analysis with analysis being done using software. ∆ time analyze DFMA manually & software × 100 time taken to analyze DFMA using software (7) Efficiency = 97.2%

Figure 4. Time comparison of DFMA analysis manually vs DFMA Software in Bahasa Melayu Analysis

A. Survey Questions

The purpose of survey is to obtain differences between manual and computer based DFMA Analysis application. This is to prove that the computer analysis eased analysis and reduce time efficiently. Each student was given a survey form in order to transmit their feelings and experienced applying DFMA manually and using this Software. The survey comprises a total of 19 selective questions. Almost all of the questions are focused on the software. Only four questions were asked based on their experience on DFMA analysis in manual method. The level of difficulties of the answers are based on numbers comprises of 1 to 5; where the lowest number is the lowest, not most difficult, not necessarily used while the highest number is the highest, easiest level, highly necessary, least time taken. The questions asked based on their experience, level of understanding of both methods, level of difficulties of both application, language proficiency, the format arrangement, instructions to ease flow, time taken to finish each tasks, the requirement of formulas, graphics and psychological aspects.

IV. CONCLUSION

“DFMA in Bahasa Melayu” software was developed in order to ease any users not necessarily engineers. All level of people can apply this software in order to decide appropriate processes and what materials to be made for a part in a company. This can minimize overall time and overall costs and increase profits. Even though this software is simple and easy to use, there still room of improvement to be made from time to time. Improvement can be made in many perspectives including time, psychological issue, length of instructions, hardware and software selection and others.


The software is important in a way for a designer to work against tight work schedule. It is rather easy to be used and not require longer time to use it. In a way of training purpose, the DFMA Software in Bahasa Melayu does not required longer time to attend appropriate or proper training due to the instructions provided in the software is simple and systematic. The software efficiency shows 97 percent better of labor efficiency especially part designers and analysis compare with manual analysis.

For further improvement, the software can also be

integrates with other Design for X applications [10]. This can improve industries profitability in terms of getting better results in their design.

The software is developed using software called Visual Basic. The instructions can be varies as instructed by the programmer. Even though this software is not developed by Computer Engineering student but it is assumed that engineering students in any higher learner institutions must have the basic of computer programming language as their pre-requisites beforehand.

In order to enhance knowledge of computer language,

this programming instruction can be simplified for future development. For example, the programmer uses a number of long instructions to develop a simple operation. The programmer usually uses Case operation in the software. Therefore, the use of Array command in Visual Basic can be applying in future development which the instruction may be shorter.

The software can also be programmed using Visual

Basic.Net [8] and MySQL PHP in order to be used in computer network in using internet anywhere [4]. In the mean time the authors is upgrading DFMA Software in Bahasa Melayu using PHP. In terms of software security, this software can be secured by applying password and username in order to allow unauthorized users [5].

The time taken to use this software can be reduces.

Therefore the time of using this software can be optimized effectively and efficiently. Instructions can be reduces and the repetitions can be minimized. The user will not be asked frequently which makes them bored. For instance, repetition used when user is asked of part orientation in the main frame and Manual Insertion Frame. More calculations can be made internally without asking user to key in instructions or to make unnecessary selections. The more selections made, the more confusing user will undergo. This kind of problem requires him or her to made further thinking before decision can be made. As a result time loss occurs.

In order to create more interest to the users, more

interactive visual effects can be added such as animated

pictures and narration of processes, Learning Guide Button for new user and analysis.

DFMA Software in Bahasa Melayu can be upgraded

and integrate with other Design for X (DFX) Software application which is useful to the industries nowadays in terms of Quality and Productivity excellence [9]. This software has a potential to be commercialized in domestic market and internationally.

In order to follow parallel with the development of

technology, it is advice to integrate the software with vision technology. Vision technology requires us to bring along samples of part to be analyze, focused the part to the camera. The camera is integrated to the software and analysis will be taken over. The results are then appears with the report in a few moment later.

V. CONCLUSION

[1] Xie, X. (n.d.). Design for Manufacture and Assembly Dept.of Mechanical Engineering, University of Utah www.cc.utah.edu/~u0324774/pdf/DFMA.pdf

[2] Ivr Oos, Design for Manufacture and Assembly to Improve Efficiency and Quality, Industrial Engineering, 1992

[3] Boothroyd Dewhrst, http://www.dfma.com/software/dfa.htm

[4] Deitel H.M Deitel, P.J Deitel, T.R. Nieto, “Visual Basic 6: How to Program”. New Jersey: Prentice Hall, 1999

[5] G.Q Huang, K.L. Mak, “Design for Manufacture and Assembly on the Internet”. Journal of Computing in Industry, Volume 38, Issue 1, 17-30, 1999

[6] Julian Case Bradley, A.C.M , Programming in Visual Basic 6.0. McGraw Hill, 2007

[7] Boothroyd Dewhurst., http://www.dfma.com/software/dfa.htm.

[8] Johnyater. Hubpages Inc. http://hubpages.com/hub/DFMA

[9] Powel,G. Beginning Database Design. Wiley Publishing Inc. 2006

[10] Tsai-C. Kuo, Samuel H.Huang, Hong-C.Zhang, “Design for Manufacture and Design for ‘X’: Concept, Applications and Perspectives”, Journal of Computer in Industrial Engineering, pp. 241 – 260, 2001.

[11] Patrick, T. The Visual Basic.Net. Prentice Hall, 2002.

[12] Hoekstra, R.L.. “Design for Assembly”. University of Cincinnati. 1992

[13] H.J Warnecke, R.Bäßler, “Design for Assembly – Part of the Design Process”, Annals of the CIRP, 1988

[14] Geoffery Boothroyd, “Product Design for Manufacture and Assembly”, Computer-Aided Design Vol 26, pp. 505-519, 1994

[15] Bayoumi, A.M.E. “Design for Manufacture and Assembly (DFMA): Concepts, Benefits and Application”. 7th Cairo University International MDP Conference. pp. 15-17, 2000

[16] Powel, G. Beginning Database Design. Wiley Publishing Inc. 2006.

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