Problem Type
Aforementioned illustration relates to the class of non-cyclic scheduling problems characterized via the subsequent features.
(a) The Flexible Manufacturing System consists of M stations (workplaces, machines) all of that can process at mainly one operation at a time,
(b) The inventory that may change at some time contains N jobs along with termed earliest possible beginning times and due dates,
(c) A job is a sequence of operations along with precedence constraints that is most operations can only be begun if one or some preceding operations have been finished.
Table no.2 (b): Due Dates Distributions for Situation E-H
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Situation A : Case 2, 30% late jobs under the FIFO scheduling rule
Demanded Throuhput Time % of
Parts
240 5
480 5
720 5
960 35
1200 50
Average Throughput Time: 1008 min
Demanded/achieved flow factor: 1.20
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Situation A : Case 2, 50% late jobs under the FIFO scheduling rule
Demanded Throughput Time % of
Parts
240 5
480 10
720 35
960 27
1200 23
Average Throughput Time: 847 min
Demanded/achieved flow factor: 1.00
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Situation A : Case 2, 70% late jobs under the FIFO scheduling rule
Demanded Throuhput Time % of
Parts
240 19
480 25
720 31
960 15
1200 10
Average Throughput Time: 653 min
Demanded/achieved flow factor: 0.78
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Situation A : Case 2, 85% late jobs under the FIFO scheduling rule
Demanded Throuhput Time % of
Parts
240 30
480 45
720 15
960 5
1200 5
Average Throughput Time: 504 min
Demanded/achieved flow factor: 0.60
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(d) For all operation, this is identify that on which stations (one or more) this can be represented and how long this acquires (containing transportation times); these durations are supposed to be independent of the scheduling deterministic and policy ,
(e) Operations which have been begun but cannot be interrupted (non-preemptive scheduling), and
(f) The idle times among the operations are not limited, neither are the buffers opposite the stations or at the output.
Consequently the major restriction is the capability of the stations. Another limitation is assumed to be of secondary significance. They may be shown via the earliest possible starting times of the operations or contained in the operation times, for instants: via adding a constant average transportation delay. Obviously, the transportation system can be integrated via adding transport operations to the work plans and explaining one or more resources that provide transport and have to be assigned as well. The only limit implied through the assumptions made is that the resource uses times are independent of the processing sequences.
In the test difficulty, the options on which station an operation is presented are only amongst identical stations. Hence, for each operation there is merely one value for its (nominal) net operation time. However, this assumption is not essential for the algorithms discussed afterward.