The department consists of a total of 7 workstations. The line is flexible enough to process 3 different products and each workstation requires a set-up for each product type. It is assumed that there is always material to supply workstation #1 (this workstation is not subject to starvation) and enough space for workstation # 7 to release Its production (this workstation is not subject to blocking).

The layout of the actual production system is shown in Figure 1. The input data such as the processing time, P_ij, of product j on machine i, the set-up time, St_ij, that station i requires to manufacture product j, the batch size of product j, nj. Further, the processing times on machine i follow a normal distribution. P_ij gives the mean of processing time of product j (see Table 1) at each of the 7 machines of the production line. The standard deviation for the processing time on:

1) machine 1 is 2,

2) machine 2 is 1.5,

3) machines 3 and 4 is 1.2,

4) machine 5 is 2.2,

5) machine 6 is 1.7,

6) machine 7 is 1.

1) Simulate this production line based on the data given above and in Table 1. Report your results of the actual situation (The mod. file and the output report).

2) During your analysis and after meeting with the maintenance manager, you were told that machine 3 is not as reliable as the other ones. Based on statistical data available in the maintenance department, you have found that this machine breaks in accordance to an exponential distribution with a failure rate ₃=0.17 failure/hour. The repair rate is also .exponential with ₃=1.1 repair/hour. What is the impact of this new input on the results obtained in I). Give the new model along with the results (The mod. file and the output report).

3) Your work as IE begins now and you have found many alternatives to improve the productivity of this production system. Among these alternatives, you find that it is possible:

1) To use more than one machine at a particular workstation.

2) To introduce intermediate buffer between two successive workstations.

3) To use both of the above in your analysis to improve the productivity.

The cost is equal in all the 3 cases presented above (by assumption), present your recommendations along with the results (The mod. file and the output report) in order to convince the general manager to adopt and implement your solution.

Hints:

Prepare a detail plan of experiment. Show in detail the steps that you need to build a suitable simulation model to calculate the cycle time of the production line.

Present the method (of your choice) used to remove the initialization bias and show that the system under study is in a steady state.