MBA 612 Sync 3 Breakout Problems

(Chapters 13 and 14)

1. Eagle Fabrication has the following aggregate demand requirements and other data for the upcomingfour quarters.

Quarter Demand Previous quarter's output 1500 units

1 1300 Beginning inventory 200 units

2 1400 Stock-out cost $50 per unit

3 1500 Inventory holding cost $10 per unit at end of quarter 4 1300 Hiring workers $4 per unit

Laying off workers $8 per unit

Unit cost $30 per unit

Overtime $10 extra per unit

Which of the following production plans is better: Plan Achase demand by hiring and layoffs; orPlan Bproduce at a constant rate of 1200 and obtain the remainder from overtime?

2. Consider the following requirements for a certain product.

Period 1 2 3 4 5 6 7 8 Gross requirements 0 200 200 500 0 400 0 400

Beginning inventory = 500 units

Setup cost = $500 per setup

Lead time = 1 week

Holding cost = $3 per unit per week

a. Develop the lot-for-lot MRP table.

b. Calculate the total relevant costs.

3. Jack's Refrigeration Repair is under contract to repair, recondition, and/or refurbish commercial andindustrial icemakers from restaurants, seafood processors, and similar organizations. Jack currently hasfive jobs to be scheduled, shown in the order in which they arrived.

Job Processing Time (hours) Due (hours)

V 20 50

W 10 35

X 50 90

Y 15 35

Z 55 75

(a) Complete the following table. (Show your supporting calculations below).

(b) Which dispatching rule has the best score for flow time?

(c) Which dispatching rule has the best score for work-in-process (jobs in the system)? (d) Which dispatching rule has the best score for lateness?

Dispatching

Rule Job Sequence SPT

EDD

Average Flow Time

Average

Number of Jobs

Average Lateness

4. The operations manager of a body and paint shop has five cars to schedule for repair. He would like tominimize the throughput time (makespan) to complete all work on these cars. Each car requires bodywork prior to painting. The estimates of the times required to do the body and paint work on each are asfollows:

Body Work

Car

(Hours) Paint (Hours)

A 8 7

B 9 4

C 7 9

D 3 4

E 12 5

(a) Use Johnson's rule to sequence these five jobs for minimum total duration. Show your work in determining the job sequence.

(b) The optimal sequence is ________.

(c) Chart the progress of the five jobs in this optimal sequence.

(d) After how many hours will all jos be completed?