Homework #3 Fall 2020
Question 1: Determine which shipping alternative would be most economical to ship 30 boxes of parts when each box has a price of $280 and holding costs are 25 percent of price, given this shipping information: overnight, $340, two-day, $200, six-day, $280.
Question 2: A manager must make a decision on shipping. There are two shippers, A and B. Both offer a two-day rate: A for $512 and B for $530. In addition, A offers a three-day rate of $480 and a nine-day rate of $411, and B offers a four-day rate of $465 and a seven-day rate of $446. Annual holding costs are 39 percent of unit price. Four hundred and ten boxes are to be shipped, and each box has a price of $144. Which shipping alternative would you recommend?
Question 1: the following table contains information concerning four jobs that are awaiting processing at a work center.
Job Time (Days)
a. Sequence the jobs using (1) First come, first served, (2) Shortest processing time, (3) Earliest due date, and (4) Critical ratio. Assume the list is by order of arrival.
b. For each of the methods in part a, determine (1) the average job flow time, (2) the average tardiness, and (3) the average number of jobs at the work center.
c. Is one method superior to the others?
Question 2: The times required to complete each of eight jobs in a two-machine flow shop are shown in the table that follows. Each job must follow the same sequence, beginning with machine A and moving to machine B.
a. Determine a sequence that will minimize makespan time. b. Find machine B’s idle time. c. For the sequence determined in part a, how much would machine B’s idle time be reduced by splitting the last two jobs in half?
Question 3: The Budd Gear Co. specializes in heat-treating gears for automobile companies. At 8:00 a.m., when Budd’s shop opened today, five orders (listed in order of arrival) were waiting to be processed.
Per Unit Time inHeat Treatment(minutes/unit)
Due Date(min. from now)
a. If the due date rule is used, what sequence should be used? b. What will be the average job tardiness?
c. What will be the average number of jobs in the system?
d. Would the Shortest processing time rule produce better results in terms of average job tardiness?
Question 4: Determine the minimum number of workers needed, and a schedule for the following staffing requirements, giving workers two consecutive days off per cycle (not including Sunday).
Question 1: For each of the following network diagrams, determine both the critical path and the expected project duration. The numbers on the arrows represent expected activity times. a. Activity-on-arrow diagram
b. Activity-on-node diagram
c. Activity-on-arrow diagram
Homework #3 Fall 2020