Common Ground is a coffee shop that has a small dining area for customers inside the store. Customers enter, get in line, place their order, pay & pickup (a single activity) and then decide whether to dine in or leave the store to get into their cars. When the customers arrive they get in line, which on average has 3 customers waiting in it. The ordering process, payment and pickup process takes an average of 4 minutes (Note that the order/pay/pickup together is a single activity). Of the customers entering the store, 80% elect to stay and dine in the store. Those that stay in the store first use the cream/sweetener station and there is an average of 1 customer waiting in line to use this station. On average, it takes 2 minutes for a customer to use this station. Customers then wait for a table, and on average there are 4 customers waiting for a table. Customers stay at their tables for 20 minutes before leaving. The throughput (average flow rate) of the store is 1 customer/minute.

a. Draw the process flow chart for this process. Be sure to explicitly show the decisions.

b. On the flow chart, calculate the inventory, flow rate, and flow time for each activity and buffer.

c. What is the average number of customers in Common Ground?

d. What is the average time a customer spends in Common Ground?