Sequence dependent setup activity question

[#1]

To do sequence dependent setup activity, I need to create setup group/key and matrix. once I do that, I can use schedule sequence heuristic and sort my orders based on setup. so I can use normal heurictics to consider setup times from the matrix and perform setup dependent scheduling..

But I have read some comments in the forum that we need to use PPDS optimization to consider setup times and optimize the schedule..

My question is,

what functionality do I get when I use schedule sequence button (and sort by setup) in rescheduling function Versus PPDS optimizer?

[Sasi2005]

Hi Swathi,

The answer to your question lies in your question itself. When you do a reschedule function or a schedule sequence you are aware how the sequence should be, i.e. Its a predefined sequence. In that sequence some of the setup times may be less or more but its a predefined regular sequence (like a sort sequence). Say for example you have a product which can be produced on two modes, the schedule sequence doesn't consider both the modes during execution, as it goes resource by resource. It's also not an optimal sequence. All these challenges are overcome by using PPDS optimizer, which is based on the weights (cost model) assigned appropriately against setup, delay , make span as well as mode costs. Its a kind of helicopter approach. Through this kind of overall approach it provides you with an optimized schedule.

I hope its clear.

Regards

Sasi

[swathi_rege]

Hi Bhushan,

Thanks for the comments.. but I am still not clear.. Let me give you an example. Please see attached screenshot and that is our setup matrix. we are not using optimizer but we would like our orders to be scheduled based on optimal setup time (we have only one mode and dont care about cost)

Questions

1. Planned order (P1) has setup group G1, P2 has setup group G2, P3 has G3 and P4 has G4. Are you saying that if I use schedule sequence button in rescheduling function and sort by setup group (ascending), then system would not care about setup matrix time/table and will just schedule P1,P2,P3,P4 in this sequence (and use routing setup times) because setup group sorting happened in G1,G2,G3,G4 fashion? or the sequence is still P1,P2,P3,P4 based on setup group sort, but instead uses setup matrix times like below screenshot?

2. Only if I run optimizer, then system will come up with optimized schedule sequence with minimum setup time like above?

Thanks

Swathi