Tutorial 9 - Solutions (Operations Scheduling)

Universitätsprofessor
Dr.-Ing. Bernd Hellingrath
Lehrstuhl für Wirtschaftsinformatik
und Logistik

Leonardo-Campus 3
48149 Münster

Tel. +49 251 83-38000
Fax +49 251 83-38009





Tutorial Operations Management
Operations Scheduling (Part 1)
Solution
Note: Please round to four digits after the decimal point.


Task 1: Order planning (one station)
a)

Sequences (FCFS-Rule)
Processing Time Due Date Starting Time Completion Time Tardiness
No. [h] [h] [h] [h] [h]
1 14 41 0 14 0
2 21 31 14 35 4
3 10 48 35 45 0
4 15 51 45 60 9
5 20 114 60 80 0
6 30 83 80 110 27
57,33

, 2


Gantt-Diagram (FCFS):




Average completion time:
1 N 1

N i1
Ci  14  35  45  60  80  110   57,33[h]
6

Maximum tardiness: 27 [h] (Job 6)

Number of delayed jobs: 3

Costs of tardiness: 3  250[€]  5[€ / h]  (4  9  27)[h]  950[€]

b)

Sequences (SPT-Rule)
Processing Time Due Date Starting Time Completion Time Tardiness
No. [h] [h] [h] [h] [h]
3 10 48 0 10 0
1 14 41 10 24 0
4 15 51 24 39 0
5 20 114 39 59 0
2 21 31 59 80 49
6 30 83 80 110 27
53,67