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THE OPEN UNIVERSITY OF SRI LANKA DEPARTMENT OF MECHANICAL ENGINEERING BACHELOR OF TECHNOLOGY LEVEL 05 MEM 5336 MANAGEMENT FOR ENGINEERS ACADEMIC YEAR 2011/12 ASSIGNMENT 03

INSTRUCTIONS (1) This assignment is based on course material presented in Book 03. (2) Answer all questions. (3) Write your registration number clearly on your answer script. Write your address

at the back of your answer script. (4) Send your answer script under registered cover to the address given below or put it into

the assignment box available at the Department of Mechanical Engineering (Block 17), Nawala, Nugegoda.

THE COURSE COORDINATOR IN MEM 5336, DEPARTMENT OF MECHANICAL ENGINEERING, THE OPEN UNIVERSITY OF SRI LANKA, P.O. BOX 21, NAWALA, NUGEGODA.

(5) Last date of submission is 9th December 2011. (6) No late submissions will be accepted. Q1 (a) Explain the following terms

Production System Production function Capacity management

(b) Discuss the different techniques involved in demand forecasting. (c) Explain the different methods available for adjusting system capacity.

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Q2 (a) Explain the benefits of implementing an inventory control system in a manufacturing organization.

(b)Explain the different types of lot size models applicable to output as well as to raw

material stocks. (c) Derive expressions for following in an economic lot size model with backorders in terms

of Demand rate, administration cost, inventory cost per unit per unit time, penalty cost per unit backorder per unit time.

Economic lot size Back ordered quantity Minimum running cost

Q3 (a) What are the objectives of implementing a preventive maintenance programme for a

process plant? (b) A process complex such as the oil refinery consists various plants. In turn each of these

plants consists of many equipment and machinery. Each of this equipment will also consist of many components in turn. How will the maintenance engineer keep a track of all such equipment and implement a suitable preventive maintenance programme.

(c) Mention five vital Documents operating in a plant and how they function within the

organization. Q4. (a) Explain the following terms.

Project management Critical Path methods Programme evaluation and review techniques Total float.

(b) A cabinet manufacturing company is planning to introduce a new model of cabinets which requires the following tasks.

Task Description Task Time(minutes) A Prepare the wheels 10 B Mount the wheels 5 C Assemble the sides 15 D Attach the top 11 E Attach the base 10 F Insert the brackets 5 G Insert the shelves 5 H Attach the doors 10 I Attach the back panel 10 J Paint the unit 15

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The wheels are mounted after they are prepared. The base cannot be attached until the sides are assembled and the wheels mounted. The top cannot be attached nor the brackets inserted until the sides are assembled. The shelves are inserted after the brackets are installed. The back panel is attached after the base and top are attached. The doors are attached after the shelves are inserted and the top and base are attached. The unit is painted after the back and doors are attached. (i) Identify the immediate predecessors of each task and draw the network. (ii) Find the critical path(s), and list the critical activities. (iii) Obtain the earliest and latest start and completion times of all the activities and their

total, free and independent floats. Q5. (a) Explain the term transport algorithm. Illustrate the above with flow diagram.

(b) Explain the methods available to find out the basic solution to transportation problem.

(c) The material transportation cost per ton of cement from different factories X,Y and

Z to four different locations A,B,C,D are given by the following matrix. Factories X, Y, Z could supply 18, 26, 20 tons of cement per week respectively. The work sites A, B, C, D require 19, 15,12,18 tons of cement every week. Find the weekly transport cost and verify whether it is the minimum cost. Hence determine the minimum weekly transport cost.

A B C D

40

40

45

35

20

25

30

25

50

40

30

35

X

Y

Z