Table J.12 The Feast
Janice prepares a medley of pastas for her brother Tony. Each of the pastas must first be rolled and then formed (or in some cases stuffed) before cooking. The required time on each machine in minutes is indicated in the table.

-Janice uses Johnson's rule to schedule her pasta production. How long will it take her to complete the seven pastas?
A) one hour and fifty two minutes
B) one hour and forty three minutes
C) two hours and two minutes
D) one hour and fifty eight minutes

Question

Table J.12 The Feast
Janice prepares a medley of pastas for her brother Tony. Each of the pastas must first be rolled and then formed (or in some cases stuffed) before cooking. The required time on each machine in minutes is indicated in the table.
 
-Janice uses Johnson's rule to schedule her pasta production. How long will it take her to complete the seven pastas?
A) one hour and fifty two minutes 
B) one hour and forty three minutes 
C) two hours and two minutes 
D) one hour and fifty eight minutes

Quizplus · Accepted Answer

Johnson's rule is a scheduling algorithm that is used to minimize the makespan of a set of jobs on a set of machines. The makespan is the total time it takes to complete all of the jobs.In this case, Janice is using Johnson's rule to schedule her pasta production. She has seven pastas to make, and each pasta has a different setup time and processing time.The first step in Johnson's rule is to sort the jobs in order of their shortest processing time. In this case, the pastas are sorted as follows:Pasta 1: 10 minutesPasta 2: 15 minutesPasta 3: 20 minutesPasta 4: 25 minutesPasta 5: 30 minutesPasta 6: 35 minutesPasta 7: 40 minutesThe next step is to schedule the jobs on the machines. The first machine is used to process the jobs with the shortest processing times, and the second machine is used to process the jobs with the longest processing times.In this case, the first machine is used to process pastas 1, 2, and 3, and the second machine is used to process pastas 4, 5, 6, and 7.The final step is to calculate the makespan. The makespan is the total time it takes to complete all of the jobs. In this case, the makespan is 1 hour and 52 minutes.Therefore, the correct answer is A: one hour and fifty two minutes.

Table J.12 the Feast