For the data given in Problem 16.6, use the extended bottleneck model to develop the relationship for production rate Rp and manufacturing lead time Mir each as a function of the number of parts in the system N. Plot the relationships as in Figure 16.16.
Problem 16.6
A semi—automated flexible manufacturing cell is used to produce three products. The products are made by two automated processing stations followed by an assembly station. There is also a load/unload station. Material handling between stations in the FMC is accomplished by mechanized carts chat move tote bins containing the particular components to be processed and then assembled into a given product. The carts transfer tote bins between stations. In this way, the carts are kept busy while the tote bins are queued in front of the workstations. Each tote bin remains with the product throughout processing and assembly. The details of the FMC can be summarized as follows:
The product mix fractions and station processing times for the parts are presented in the table below. The same station sequence is followed by all products: 1 →2 →3 → 4 → 1.
The average cart transfer time between stations is 4 min. Use the bottleneck model to determine: (a) What is the bottleneck station in the FMC, assuming that the material handling system is not the bottleneck? (b) At full capacity, what is the overall production rate of the system and the rate for each product? (c) What is the minimum number of carts in the material handling system required to keep up with the production workstations? (d) Compute the overall utilization of the FMC. (e) What recommendations would you make to improve the efficiency and/or reduce the cost of operating the FMC?