Question

Consider the following four--?step assembly operation with quality problems.

-The first resource has a processing time of 7 minutes per unit and one employee doing the operation

? The second resource has a processing time of 4 minutes per unit. It also has one employee doing the operation. However, this is a very delicate task and 0.79 of all products have to be scrapped after this step.

? Two workers are staffed for the third resource. No quality problems occur at this resource and the processing time is 17minutes per unit.

? At the fourth and final resource, one operator handles the product. No quality problems exist at this step and the processing time is 12 minutes per unit.

What is the process capacity per hour? (keep two decimal)

Answer 1

The effective processing time at first resource = 7 minutes / unit

Sine 0.79 of all products have to be scrapped, it is only 0.21 of all products pass on as good products to third resource. The second resource has a processing time ( good + bad products together ) of 4 minutes.

Therefore effective processing time of good products at second resource = 4/ 0.21 =19.04 minutes / unit

Effective processing time at third resource with no quality problem = 17 minutes/ unit

Effective processing time at fourth resource with no quality problem = 12 minutes /unit.

It is the capacity of the bottleneck resource which will decide capacity of the whole process .

The bottleneck resource is the one which takes maximum processing time per GOOD unit.

The bottleneck resource in this case is second resource which takes 19.04 minutes/ unit

Therefore , overall process capacity = 19.04 minutes/ unit

Hence process capacity per hour = 60 / 19.04 units = 3.15 units

PROCESS CAPACITY PER HOUR = 3.15 UNITS