a) Process capacity is the maximum units it can produce. As the cooling rack can hold maximum 20 units at a time so that will be the capacity of this process.
The bottleneck operation is the the step which takes maximum time, here step 4 i.e cooling rack takes maximum time of 50 mimutes so it is the bottleneck operation
cycle time is the time required to convert raw material into finished goods. it is 50 minites here, as the demand is 15 but supply is done at 10 per hour so itis supply constrained.
b) I think increasing the batch size to 20 will lead to less setup time required after every batch and thus increased throughput in less costs thus more revenue.