Practice Problem: Chapter 15, Short Term Scheduling

Problem #1. Prepare the Input-Output report for the following work center.

Week ending / 1 / 2 / 3 / 4
Planned input / 400 / 380 / 410 / 370
Actual input / 350 / 390 / 400 / 370
Cumulative deviation / 0
Planned output / 410 / 400 / 400 / 370
Actual output / 380 / 400 / 380 / 400
Cumulative deviation / 0
Backlog / 80

Problem #2: Assignment problem – Problem #15.7 (page 611)

The Akron Police Department has five detective squads available for assignment to five open crime cases. The chief of detectives wishes to assign the squads so that the total time to conclude the cases is minimized. The average number of days, based on past performance, for each squad to complete each case is given.

  1. Solve the problem using assignment method.
  2. Solve the problem if squad 5 cannot be assigned to case E.

A / B / C / D / E / F / G / H
11
12 / Case
13 / A / B / C / D / E / Case on squad
14 / Squad / 1
15 / 2
16 / 3
17 / 4
18 / 5
19 / Squads on case
20
21 / Objective to minimize: / Total time =

Solver parameters

Set Target Cell
Changing cells
Constraints

Options:□ Assume linear model□ Assume non-negative

Problem #3:Five jobs are to be done at custom furniture shop:

Today's calendar day = 130
Job / Date order received / Processing time (Days) / Date order due / Days till due date / CR
A / 110 / 20 / 180
B / 120 / 30 / 200
C / 122 / 10 / 175
D / 125 / 16 / 230
E / 130 / 18 / 210

A.SPT schedule

Job / Processing time / Delivery Promised / Completion time (Flow time) / Lateness
Average completion time:
Average lateness
Average number of jobs in the system:
Utilization

`B.EDD schedule

Job / Processing time / Delivery Promised / Completion time (Flow time) / Lateness
Average completion time:
Average lateness
Average number of jobs in the system:
Utilization

C.Critical Ratio schedule

Job / CR / Processing time / Delivery Promised / Completion time (Flow time) / Lateness
Average completion time:
Average lateness
Average number of jobs in the system:
Utilization
SPT / EDD / CR
Average completion time:
Average lateness
Average number of jobs in the system:
Utilization

Problem #4: A rework operation for damaged circuit boards has two operations that all jobs follow. For the setoff jobs listed below,

  1. Find the sequence that will minimize total completion time, i.e. makespan.
  2. Determine the amount of idle time for the second operation.
  3. What jobs are candidates for job splitting? How much would the idle time and makespan be reduced?

Job / A / B / C / D / E
Operation 1 / 24 / 10 / 32 / 30 / 12
Operation 2 / 28 / 15 / 25 / 28 / 8

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