Consider a CONWIP flow line with 3 stations in series (1à2à3); each station consists of a set of identical machines. The throughput capability (production rates) of stations 1, 2, and 3, are 3, 2, and 4 units per hour, respectively, and the corresponding unit processing times are 2 hours, 2 hours, and 1 hour. Answer the following questions using the data specified.
Calculate the bottleneck rate, the raw process time, and the critical WIP for this line.
Can the critical WIP exceed the number of stations in a line? Can critical WIP exceed the number of machines in a line? Explain the logic behind your answers.
How many identical machines are currently there at station 2?
If WIP is managed so that it averages w = 6 units, compute the best case, worst case, and practical worst case throughput and the corresponding cycle times for the line.
Based on the available information on the flow line, would you expect the actual line’s throughput to be smaller or larger than your Practical Worst Case estimate?(Explain your reasoning–this question is asking you to examine if the assumptions behind the PWC calculations are satisfied by the line or not and if not what the impact of assumption violation is likely to be.)
If you could not change the bottleneck rate and the raw process time for the line, what could you do to increase the practical worst case throughput to double the value that you obtained in your answer to part d above?