Examine the process flow chart below. The process is stable. The following information is known.

Process	Activity Time (minutes)	Storage	Average Inventory
1 2 3 4 5 6 7	20 15 12 15 15 20 30	1 2 3 4 5 6 7	??? 4 1 1 5 1.5 5.167

It is also known that after process 2, 25% of the flow units move on to storage 3 and the remaining 75% are routed to storage 5. As well, after process 5, 70% of the flow units move on to storage 7 while 30% move on to storage 6. If the entering flow rate is 40 units per hour, and if the overall inventory level throughout the process is 74.8333, answer the following questions.

a) What is the total inventory in department B (store 3, process 3, store 4, and process 4)?

b) What is the flow time (T) for the entire process? What is the theoretical flow time and flow time efficiency?