Mr. K’s is a very popular hair salon. It offers high-quality hairstyling and physical relaxation services at a reasonable price. The service process includes five activities that are conducted in the sequence described below. (The time required for each activity is shown in parenthesis):

Activity 1: Welcome a guest and offer homemade herb tea. (10 minutes)

Activity 2: Wash and condition hair. (15 minutes)

Activity 3: Neck, shoulder, and back stress release massage. (9 minutes)

Activity 4: Design the hairstyle and do the hair. (24 minutes)

Activity 5: Check out the guest. (6 minutes)

Three workers (S1, S2, and S3) are staffed to this assembly line, and the assignment of tasks to each workers is: S1 does Activity 1. S2 does activities 2 and 3. S3 does activities 4 and 5.

(a) Which worker is the bottleneck of the process? What is the process capacity in [units/hour]?

(b) What is the idle time of each worker in [minutes]?

(c) At a wage rate of $15 per hour, what is the cost of direct labor in [$/unit]??

(d) Mr. K contemplates redesigning the assignment of tasks to workers. For this, Mr. K is evaluating the reassignment of Activity 5 from S3 to S1. What would the new direct labor cost be? Is this reassign an improvement?