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,

Yes, if you use the setup group as a sorting parameter in the strategy profile and you run the Reschedule heuristic, then you will get with the sequence G1,G2,G3,G4. Please note you are having only one order per group here, which is generally not the case ,in practice. The advantage of this method is all orders involving G1 you would like to run in a single run say you have 5 orders of G1 group, 2 Orders of G2 group, 1 order of G3 and 2 orders of G4 and the setup time change over between G1 and G2 or G2 and G3 is very large and similarly others then it makes sense to run all orders related to G1 first thus you need not to have a setup activity between consecutive orders of G1 and similarly other groups . So it depends on the business scenario what you want to achieve.setup-group.png setup-group-result.png

In case of optimizer it takes the weightage of parameters that you are configuring , in some industries it could be setup time in some industries it could be delays (delay has higher importance than setup). Thus producing a result which takes all the constraints not just setup before producing a result. setup-opti.png.

I have attached some screen shots for your ready reference, the reschedule using setup group (setupgoru-result.png) and the optimiser in the file (setup-opti.png). Hope this helps.

Regards

Sasi

[swathi_rege]

Thanks a ton.. One last question before closing the thread

so in reschedule heuristic, if I sort using setup group, then below things will happen

1. Sequences all orders based on setup group (for example - G1, G1,G1, G2, G2, G3, G3, G4, G4, G4) - Clear from your screenshot

2. The setup time between G1 and G2 - It be read from setup matrix but not from routing (please confirm)

If I use optimizer, then setup sequence will be like below (G1, G1,G1, G4, G4, G4, G3, G3, G2, G2 - optimized based on time)