Mr. K’s is a hair salon whose service process includes six activities conducted in the sequence described below. (The time required for each activity is shown in parentheses):

Activity 1: Welcome guests and serve herb tea. (10 minutes)

Activity 2: Offer styling suggestions. (15 minutes)

Activity 3: Condition hair. (10 minutes)

Activity 4: Do the hair. (30 minutes)

Activity 5: Wash hair. (10 minutes)

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

Three servers (S1, S2, and S3) offer the services in a worker-paced line. The assignment of tasks to servers is as the following:

S1: Activity 1 and Activity 2.

S2: Activity 3 and Activity 4.

S3: Activity 5 and Activity 6.

Q1) What is the process capacity in [customers/hour]?

Q2) If the demand of Mr. K’s is one customer per hour, what is the cycle time (in minutes) of the process?

Q3) If the demand of Mr. K’s is one customer per hour, what is the idle time of S3 (in minutes) while serving one customer?

Q4) If the demand of Mr. K’s is one customer per hour, what is the average labor utilization (in %) of the servers?

Q5) Assume that Mr. K’s pays each worker an hourly wage of $18 per hour. What is the cost of direct labor in [$/customer] when the demand is one customer per hour?

Q6) Now assume that the demand has surged to 6 customers per hour. What is the average labor utilization (in %) of the servers?

Q7) Assume that Mr. K’s pays each worker an hourly wage of $18 per hour. What is the cost of direct labor in [$/customer] when the demand is 6 customers per hour?

Q8) One morning when the salon opened, 5 customers were waiting to receive service. How long (in minutes) will it take to finish serving these 5 customers starting from the empty service process? Recall that the process is a worker-paced line.

From now on assume that the demand is 6 customers per hour. To increase the service rate, Mr. K’s is considering two alternatives:

Alternative I: To hire a new employee to help S2 (the bottleneck server) without changing the activities performed by each server.

Alternative II: To balance the line. For this, Mr. K’s is evaluating to reassign Activity 3 from S2 to S1. Thus, after line balancing, S1 will be assigned Activities 1, 2 and 3; S2 will be assigned Activity 4; S3 will be assigned Activities 5 and 6

Q9) What would be the costs of direct labor under Alternative I in [$/customer]? Assume that Mr. K’s pays each worker $18/hour. (Assume that the demand is 6 customers per hour.)

Q10) What would be the costs of direct labor of serving one guest under Alternative II in [$/customer]? Assume that Mr. K’s pays each worker $18/hour. (Assume that the demand is 6 customers per hour.)