1. Consider the following four-step assembly operation with quality problems. Each resource is staffed by one employee, there are sufficient inventory buffers between steps.

• The first resource has a processing time of 5 minutes per unit.
• The second resource has a processing time of 6 minutes per unit.
• The third resource has a processing time of 3 minutes per unit. With a 30% probability, the flow unit coming out of the third resource must be reworked. In that case, the operations at the first, second, and third resources are repeated. You can assume that (a) rework always succeeds (i.e., a unit going through the rework loop will always work after the third resource) and (b) the processing times for units in rework are the same as for regular units.
• The fourth resource has a processing time of 4 minutes per unit.

a) What will be the capacity of the first step, if there is a setup time of 20 minutes each time you start a production batch and each such batch contains 8 units? b) What would be the first improvement change you would consider recommending for this four-step assembly line and why?