Consider a 3-stage service process represented by the following flowchart. Stage 1 is operated by employee 1. Stage 2 is operated by employees 2a and 2b, who work in parallel and provide the same service with identical service times. Stage 3 is operated by employee 3.

According to the flowchart, each customer is first serviced by employee 1. Then, the customer visits either employee 2a or employee 2b to receive the service at stage 2. Finally, the customer is served by employee 3 to finalize the service.

An analyst developed a Gantt chart to visualize the service for the first 2 customers.

According to the Gantt chart, what is the process time of this service system? [Hint: 1. According to the Gantt chart, customer orders arrive every 30 seconds or more frequently. 2. Process time of the system is the time between two outputs if the system operates at the capacity rate.]