Process Analysis

A manufacturing cell makes two components, X and Y, that are sent to a small assembly area where the two components are then assembled together with a third assembly Z (sourced externally) to produce one end item. The cell can only make one of the components at a time. Each end item requires one of component X, two of component Y, and one of the assembly Z.

The final assembly area has storage areas to hold X, Y, and Z that for all practical purposes has no limit to how much it can hold. Purchasing makes sure to have sufficient quantities of Assembly Z on hand at all times to assure that the final assembly area is never starved for Assembly Z. The final assembly area is dedicated to this one end item. Once end items are complete, they are moved by an automated conveyor belt to the packaging department.

The manufacturing cell requires some non-productive setup time to changeover from making X to making Y, and again when switching back to making X again. Because of this, the cell produces X and Y in batches to minimize the effect of non-productive setup time on the productivity of the operation. Currently, the cell produces a batch of 100 of component X, followed by 200 of component Y, and then the cycle repeats itself. Completed units of X and Y are sent to the final assembly area currently under a batch flow concept where X and Y are stored in the cell under a complete batch of each is complete and then X and Y are moved to the final assembly area. The plant is considering automating this transfer via conveyor belt so that X and Y follow a unit flow concept, moving directly to the final assembly as soon as each unity is complete in the manufacturing cell. They want to know what the practical impact of this change would be.

Following are data on the processing times for the two components and the end item:

Table: Processing times for 2 components with end time

Item	Setup Time	Runtime per Unit
Component X	15 minutes	0.25 minutes
Component Y	20 minutes	0.10 minutes
End Item	NA	0.50 minutes

a) Draw a flow chart of this process. Make it as detailed as you see fit. Label it as needed. Please use the drawing tools in Word, Excel, or PowerPoint to make this easier.

b) Explain what is the maximum hourly output of the system in the long run? What is the bottleneck of the process?

c) Perform a WIP inventory analysis of both Component X and Component Y, taking into consideration the final assembly operation. Perform the analysis under the following two scenarios. In each case, Components X and Y are considered WIP as soon as they are made in the cell until they are consumed in the final assembly process

1) Batch Flow: Components X and Y are not moved to the final assembly area until a full batch of both items is complete. (WIP is stored both in the cell and in the assembly area.)

2) Unit Flow: Components X and Y are automatically moved to the final assembly area as soon as each unit is completed by the cell. (WIP is stored in the assembly area only.) Final assembly completes end items as long as it has all available material to make a unit.

Good inventory analyses will have an inventory level graph for one full repeating processing cycle and a computation of the average WIP levels for X and Y. You do not need to differentiate between WIP in the cell and WIP in the assembly area just assume a single WIP area between the two activities. For both scenarios, ignore the transit time from the cell to the assembly area. State any assumptions you make in your analysis. *Don't forget the setup times in your analysis*