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EGM305 Assignment 1 Question 1 (40 marks) Explain how cellular layout can facilitate lean production

Mechanical Engineering

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EGM305 Assignment 1

Question 1 (40 marks)

1. Explain how cellular layout can facilitate lean production. 

(5 marks)

 

2. A manufacturing company is considering to adopt cellular layout to facilitate its move to a lean production system. The following table summarises the relationships of 7 different machines and 9 types of parts in the production process. Use rank order clustering technique to group the machines into machine cells and cluster parts into part families (show your full workings).  (15 marks)

 

				Part (i)
Machine (j)	A	B	C	D	E	F	G	H	I
1	1			1				1
2					1				1
3			1		1				1
4		1				1
5	1							1
6			1						1
7		1				1	1

                                                                                                      

3. After the machines are grouped into machine cells, assuming there is one machine cell consisting 4 machines, and the 4 machines need to be arranged in the most logical sequence in order to minimise the material flow in the production process. Based on the machining requirements, the analyst has recorded the following table that shows the parts moves among the 4 machines. 

           

		To
From	1	2	3	4
1	0	5	0	25
2	30	0	0	15
3	10	40	0	0
4	10	0	0	0

                                                                                                      

1. 1. Decide the machine arrangement sequence and show your full workings in your answer.

(10 marks)

 

 

 

 

1. 2. Draw the network diagram and indicate the in-sequence moves, bypassing moves and the backtracking moves.
      5. marks)

 

1. 3. Calculate the percentages of in-sequence moves, bypassing moves and the backtracking moves.
      5. marks)

 

Question 2 (40 marks)

 

A production process includes 15 activities as shown in the table below. These activities are conducted in a production line composed of a number of workstations. The activities, activity durations, and activity precedence constraints are as follows:

 

Activity	Activity Duration (Seconds)	Preceded by:
1	8	-
2	25	1
3	15	2
4	17	-
5	21	1
6	18	1
7	20	4
8	13	6,7
9	12	5
10	19	9
11	10	3,8
12	11	10
13	6	11
14	9	12,13
15	7	14

 

The production process is planned to operate for 40 hours per week and must meet the customer demand of 3600 products in each week.

 

1. Construct the precedence diagram for the above activities of the production process.
   5. marks)

 

2. Calculate the Takt time for the process in order to meet the weekly customer demand.
   5. marks)

           

3. Use the largest candidate rule technique to balance the production process, show your full workings in your answer.

                                                                                                      (20 marks)

           

 

4. Compute the balance loss and explain the implication of the balance loss. What can you suggest to improve the line balancing?

(10 marks)

 

Question 3 (20 marks)

 

1. Assuming a product is to be routed through six stations in a batch production. The setup and operation times for each station are given in the table below:

 

Station	Setup time (hour)	Operation time (minute)
1	4	5.0
2	2	3.5
3	8	10.0
4	3	1.9
5	3	4.1
6	4	2.5

 

If the batch size is 100 and the average non-operation time is 12 hours per station, determine the manufacturing lead time.

1. 10. marks)

 

2. The setup time for one particular operation during the process routing for a part is 4 hours. The actual machining time is 3 minutes, workpiece handling time is 1 minutes, and the tool handling time is 30 seconds. Calculate the average production rate for a batch of 100 parts.
   10. marks)