ASSIGNMENT

NICMAR / SODE OFFICE

NAME-Ajay

REG. No.-214-08-11-12287-2161

Course No.-PGCM 13

Course Title-Materials and Equipment Management

Assignment No.-

Date of Dispatch-

Last date of receiptOf Assignment at SODE office-

ASSIGNMENT

ON

Materials and Equipment Management

PGCM 13

SUBMITTED BY:

Ajay,

PGCM,

REG NO: 214-08-11-12287-2161

ASSIGNMENT:Your company has been awarded a contract of developing and construction a new International air port 30 KM froma city. You have been appointed asPlanning Engineer (Materials and Equipment). Project is to be implemented in phases. In phase I, one strip of landing 100 m width is to be constructed in 100 days. The scope of work is as follows:- Cutting and Dozing of 100,000cum of earth. Average height 0.75m. Transportation of 20,000 cum if surplus earth from site to dumping place 3k.m. away from site (including spreading.) Filling of 80,000 kms in landing strip. Bringing in 3000 cum of sand from 20k.m. (including spreading and leaving at site.) Procurement of 1, 50,000 liters of Bitumen. Duration of work 30 days from 60th day of starting of work. Bitumen to be obtained from refinery at Bongaigaon in Assam. Lead time up to site is 45 days. Storage facility available at site 50,000 liters tank.Estimate total cost of work and your plan of:i. Equipment Planning Procurement & Deployment.ii. Ordering and replenishing of Bitumen.Scope of work:100m width of Road construction for international airport 30 km away from city -

Cutting and dozing of 100,000 cum of earth. Average height 0.75m

Transportation of 20,000 cum of surplus earth from site to dumping place 3 km away from site. Filling of 80,000 cum in landing strip.

Bringing of 3000 cum of sand from 20 km including spreading and leveling at site.

Procurement of 150,000 liters of bitumen from refinery at Bongaigon in Assam.

Description of Equipments:

Hauling equipments Tractor: Tractors have many uses asconstruction equipment. Use ofthis, primarily may be to pull or push goods, they are also used as mounts for many types ofaccessories such as frontend shovel, rippers, bulldozers, side brooms, hoes, trenches and others. There are sizes and types to fit almost any job for which they are usable. Tractors may be divided into 2 major types crawlers and wheels.

Dumpers Dumper is a heavy duty truck with a strongly built body which is hinged at backand is fitted with a hydraulic ram on the underside to lift the front of the body and tilt itbackward into the dumping position. A tailgate may be fitted at the rear of the body or thebody may have a chute like shape in the rear with inside corner rounded and sides tapered to facilitate dumping which is most popular now-a-days. Useful life of dumpers is generally 8-12 years i.e. 10,000 15,000 hours depending upon their capacity. The lifeis also expressed in terms of kilometersi.e. 200.000 kms.

Earth moving machines These equipments are used to cut the earth or trees, rocks and then move them to a distance required. Equipments like bulldozers are also used for leveling offthe ground, cleaning land of timber, stumps, spreading earth fill etc. These equipments are very common of all the earth moving machines, a bulldozer is most useful and most theproject sites require its use in one form or the other.

Bulldozers Bulldozers are basically a pushing unit consisting of a tractor either crawlermounted or wheeled to which a cutting blade is mounted at the direction perpendicular to the direction of travel. There is no difference between a bulldozer and anglodozer except that the cutting blade is set at an angle with the direction of travel.The size of the bulldozeris indicated by the length and height of the blade, its shape and capacity. The size of blade varies from 1.7mX 70 cm.(height) X0.7m3 (capacity of blade)to 3.38mX1.14mX3.7m3.Working of dozer consists of lowering front blade to the ground. The moment dozer drives, it cuts and pushes earth collected in blade to a desirable distance.

Compaction Equipment:Tandem Roller - There is also a smooth wheeled roller with to roller wheels of approximately the same width- one at the front and other at the rear. Compaction with this type is better. This roller is better for rolling finishing surfaces as it produces smooth and even surface.

Bitumen Plant:Bitumen Boiler - This is used for heating bitumen from drums. Boiler is fitted with a firebox, fuel tube and chimney. Full asphalt drums are lifted to the top where the contents are emptied and heated by flame or combustion gasses. The boiler is mounted on the wheels and can be towed from one location to the other.

Bitumen Spraying Equipment : Bitumen boiler is fitted with the pump with strainer in the suction pipe. The pump is operated either by hand or mechanically. On the delivery side there are flexible pipe spray bars and spray nozzle. The rate of application of bitumen can vary by adjusting the height of the spraying nozzle above the ground. Uniformity ofspraying is control by the angle at which the spray bar is kept.

Bitumen Tanker : When bulk bitumen is to be transported, tanker is used. It is mounted on a truck or a trailer. Capacity of the tanker may range from 5000 to 15000 liters. Oil fireburners are used to maintain the temperature of bitumen during transit.

Bitumen Pressure Distributor: This equipment is used when a specified quantity of hotbitumen is to be sprayed uniformly for grouting or surface dressing. It is used with bulkbitumen supply.Estimating and requirement of the equipment:

Equipment on roadwork (or on any work) has either to be purchased, obtained on hire or transferred from some other project. In either of the cases a fairly accurate estimate of the requirement ofequipment has to be done so as to ensure that expenditure on equipment is not wasted. This needsplanning well an advance.

Factors to be considered are:1. What ismostdesirable sequence of operationsinvolved inthe work?

2. Whichare theoperationsare tobe performed bythe machinery?

3. In case some or all equipment is to betransferred from other projects how theprogram of both projects to be arranged so that there is no undue to and from movement of the equipment and at the same time the work is completed in optimum time.Data Required:1. Quantities of items of work: Road project is sub divided in operations like

A. Earthwork.B. Aggregate production.C. Transporting Aggregate to road.D. Compaction.E. Wearing surface Concrete / Bituminous surface etc. Quantities of items are worked out.2. Period of completion of project. Normally road work has to be completed in a stipulated period particularly when the work is to be completed on contract. In such cases the duration of the constituent operation has to be adjusted taking in to consideration the activity interrelation and overall period of completion. While fixing ofactivity duration due allowance must be made for bad weather, monsoon, and loss of time due to shifting of equipment, break down, repairs and maintenance of equipment.

3. Normally no work is possible for 3 to 4 months in a year due to monsoon. Further considering weekly holidays normally 25 days could be considered to be available forworking. Though a working day is considered to comprise 8 hours, a partis spent in inevitable operations like shifting, waiting etc. thus in about 200 days available, working hours could be about 1200-1500.

4. From above a fair estimate of requirement of equipment can be done. Over the above this suitable provision ( to the extent of 10%) is done as stand by to take care of breakdown or unforeseen circumstances.

Determine the output of a bulldozer from the following operating conditions: Material: SandSwell = 20%Haul Distance = 40mRated mold board capacity = 3 cubic meter (loose volume)Operating factor 45 minutes/ hourSolution:Probable round trip timePushing 40m @ 2.5 kmph = 0.96 minuteReturning 40m @ 5 kmph = 0.48 minuteLoading shifting gear = 0.30 minute 1.74 minutesTime per Trip = 1.74 minutesTrip per hour = 34.5 Trips

Net Mold Board Capacity = 3/1.2 = 2.5Output per Hour = 86.25 m3Output per day = 86.25 * 8 (hours) = 690 m3Cutting and dozing of 100,000of earth = 100,000/690 = 145 daysEquipment operating cost:The cost of operating the equipment includes fuel costs, routine maintenance costs, major repaircost, operators cost, tyre replacement cost, and overhead costs.

Fuel costs:

Cost of fuel consumed in one hour = cost per litre X hourly fuel consumption

Hourly fuel consumption = Hourly fuel consumption at full load operating factor.The fuel price litre, delivered at the site is obtained from local suppliers at it varies from place to place. The rate of consumption depends upon the type of engine (diesel or petrol), the state of the engine and the working conditions.

Diesel engine fuel consumption per hour = 0.15 liters X rated HP X load factor.

Petrol engine fuel consumption per hour = 0.22 liters X rated HP X load factor.

For example: The hourly fuel consumption of a crawler tractor rated with 250 HP, operating underaverage conditions (load factor 70 %) and diesel costing Rs. 35 per litre., can be worked out as under:

Diesel consumption per hour = 0.15 * Rated flywheel Hp * load factor = 0.15 * 250 * 0.7 liters = 26.25 liters

Cost of hourly consumption = Diesel consumption * rate of diesel per litre = 26.25 liters * Rs 60 (current rate) = Rs. 1575

Routine maintenance costs:Maintenance costs include the cost of lubricating oil, grease, filterbatteries, minor repairs, and the labour involved in performing maintenance. The maintenance cost including service, labour cost and minor repairs vary with the type ofequipment involved and the project environment, and these can be approximately calculated asproportion of hourly fuel cost asfollows.

Operating conditionsHourly maintenance cost

Favourable1/4 Fuel cost

Average1/3 Fuel cost

Unfavourable1/2 Fuel cost

Major Repair Cost: Repair cost = Depreciation cost * Repair cost

Repair cost during nth year = n * Value to be depreciated / Digit sum of equipment life in years

For example: If the total value of depreciation of a wheel equipment (repair factor = 0.75) works out as Rs. 375,000 and its life is 5 years, than the repair cost during each year of operation(working 1500 hours per year) can be estimated as under:

Total repair cost = Total depreciation * Repair factor= 375000 * 0.75= Rs. 281250

Tyre cost for wheel equipment:The tyre manufactures provide indication of tyre life but these should be taken as guidelines.

Hourly tyre replacement cost =115 * tyre price * no. of tyres / Tyre life in hours

Example: If the four tyres of equipment each costing Rs. 2500, are replaced after 800 hours and the tyre can be recapped locally, then the hourly tyre cost calculated as follows: = 115 * 4 *Rs. 2500 * 0.8 / 800= Rs. 115/hr.

Manpower cost: Equipment requires operators, drivers and helpers for its operations. The number of persons working on equipment varieswith type of equipment. Adumper may have only one driver-cum-operator whereas a bulldozer will need one operator and a helper. Depending upon the persons require per machine, the prevalent wage rates and the facilities provided by the company, the hourly manpower costs can be calculated.Selection of Construction Equipment: Proper selection of equipment increases the speed ofconstruction and makes project most economical. Some general consideration may be made forselections of construction equipment are: As far as possible only equipment available with ease should be selected. Unless and until it is ascertained that new equipment will earn more than its cost or cab used in future also it should not be purchased. Economics should be worked out. Choice should be restricted to standard equipment; special equipment should be selected if job satisfies its selection. Topography conditions, type of soil existing approaches and road working conditions etc. must be studied. Less variety of equipments should be used; more variety means more skilled workers, more spare parts requirements and more production cost. It is better to purchase equipment manufactured in our own country. This will decrease the cost of repairs and down-time cost. It will be beneficial to the nation also. As far as possible equipment of same make should be purchased. Size of equipment should be made according to the amount of work. It is better to use more than one equipment of small size than using of one of large size. Obsolescence of the equipment should not be overlooked. Equipment should be capable of doing more than one job, but is should not be versatile. The technical and economic aspects should be analyzed to select the equipment.

Following aspects need detailed consideration at the selection stage:1. Suitability for the job with specific reference to climatic and other operating conditions.2. Size of the equipment.3. Standardization and variety reduction.4. Type of prime mover.5. Degree of utilization.6. Suitability of local condition.7. Adaptability8. Technical considerations.

The choice of size of the equipment is indicated as either a minimum number of large size machines or several units of medium/small size machines.Technical consideration for selection should include the following points.1. Strength2. Vibration stability3. Resistance to wear4. Heat resistance5. Reliability6. Maintainability

Equipment can be classified as:1. Standard equipment.2. Special equipment.

It depends on extent of its use, availability and cost. One equipment standard for one may be special to other, for example a concrete mixer of specific capacity is a standard equipment for all most all the contactor whether class Aor class D but cranes or concrete mixer ofvery large capacity are special to one whilst standardfor other. One definition for standard equipment is that which is easily available in the market. It is easy to repair; spare parts are easily available and can be disposed off easily. Whilst special equipment manufactured on order and cannot be disposed ofeasily and cannot be repaired by all. In general special equipment can be defined as equipment manufactured for a single construction project or for a specific job.

Material Management: The management of materials in project is different from that in an ongoing situation.Most of the materials in projects are bulky and heavy.The lead time for procurement of materials in most cases is usually much more.The principle of EOQ has very limited applicability in project situations. Usually sequential arrival of material is desired.The demand of material in project is by and large highly deterministic.Sufficient care has be taken in the selection of vendors has significant impact on the projectperformance.The demand of materials in a project situation is highly deterministic. The gross requirement ofvarious materials is worked out during the detailed project report stage. The primary concern in material planning for project is that the cost of not meeting a demand is very high. As it may lead to delay in proper completion. Hence the right time is the key word in material planning for projects. The capital requirements are to be planned in such a way that these are available at the site justbefore the erection/ installation of these. The demand of construction is known as soon as the resource requirement for the project is finalized. These materials are normally required before the construction can start and are to be planned for availability prior to the construction phase of theproject. The consumables are usedthroughout the project duration and the total requirements are known. However the consumptionrate at different period is different but deterministic. As the total number of consumable materials may run in to hundreds, the analysis of aggregate demand pattern may be restricted to high consumption value materials only.Procurement is of special significance in a project situation. The net effect of delay in delivery and supply of inferior quality of material is delay in the completion of the project. Economicprocurement is also very important as it is determinant for the viability of the project. Because ofthese considerations vendor selection plays an important role.The consumables are standard materials and are usually available from many sources. Occasionally there is a scarcity of some of these materials. The gross demands as well as the demand profile ofthese materials for the entire project duration are known, and it is desirable to enter into contracts with the suppliers.

Apart from this discussion on the technical details and price the negotiation can centre on the following issues:

Ordering Schedule: To match with the project network. The suppliers network for manufacture can also be discussed. Payment terms Liquidated damages Quality specifications and procedures for checking quality Inspection at different stages of manufacture at the suppliers premises. Incorporation of design changes while the manufacturing is in progress. Performance guarantee etc. The inventory replenishment model shows the numberof cycles of replenishmentduring the usage period. The initial inventory of materials at the start of the workconsists of working stock (Q) and safety stock (S)

Economic order Quantity: Two important decision to be take while repetitive materials inventory are how much to order at one time and when to order this quantity, or in other words, to decide their order the quantity level and the reorder time cycle so as to effect economy in cost of purchasing and holding inventory. This economic order quantity (EOQ) and the numbers of orders are determined mathematically as under:Inventory cost C = Ordering cost + Inventory carrying cost C = Co. N + Ci. A/2N

For cost to be minimum: dC/dN = Co Ci. A / 2. N2 = 0 N2 = Ci. A / 2. Co

And C = CoN + Ci A/2N = 1/2N (2Con2 + Ci A) = 2Ci A/2NTherefore Least Inventory cost = square root of 2CoCiA

Safety Stock: It is the floating stock held to cater for changes in rate of consumption, delays in delivery of materials from the agreed dates and under unforeseen causes, so as to prevent stock-outs resulting in production hold-ups.The safety stock for a given situation can be determined using statistical techniques. Generally, a minimum safety stock can be taken as equal to consumption quantity in lead time period.

Lead Time: It is defined as the total time required for replenishment of an item of material from the time and indent is submitted to the purchased department, to the time that ready for use materials are received at the project stock-yard for storage or delivered at the site of work.

Reorder level: It is the level at which the stock is ordered. This is determined by adding assessed consumption during the lead time period to the minimum stock level.

Recommendations / Conclusions:

As can be seen the management of materials in a project is very much different that in an on-going organization. It calls for decisions which are very much related to the specific project situation and improper attention to this function in projects may lead to undesirable cost and time overrun. As bitumen is brought from long distance and the lead time is more, it is better to post a material expeditor and loading point for better follow up and ensuring timely delivery at site.

Bibliography:

NICMAR lesson book Construction Equipment Management and Construction Material Management Construction Planning Equipment and Methods Tata McGraw Hill Other miscellaneous hand books on Construction Equipment and Materials.

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