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Sequence heuristic by Method

Experimenter
Experimenter

I am struggling with the problem that I need to come up with a production schedule subject to some specific sequencing rules. I was wondering if this possible by making use of a method.

 

The general problem (I can't be more specific because of confidentiality):

 

Every week 900 orders arrive. Each order has 4 attributes with different possibilities. There are 24 unique combinations (i.e. 24 entity types with different characteristics A-X). The sequence of these orders are random and thus a production schedule has to be created.

 

In the appendix you will find an excel file with 900 random orders. In a text box I try to explain the different sequencing rules and how they might be implemented in a method. The problem is that I don't know how to translate this into a method in Plant Simulation. Furthermore, in the appendix a simple simulation file is attached in which I created the 24 different entities with different user specified attributes.

 

My question: Is it possible to translate those rules into a method by making use of the approach I describe in the excel file (or an approach with similar results)? If yes, can you help me on how to do this?

Thank you in advance.

3 REPLIES

Re: Sequence heuristic by Method

Gears Esteemed Contributor Gears Esteemed Contributor
Gears Esteemed Contributor

look here for an example:

 

https://www.bangsow.eu/detail_en.php?id=622

 

For distribute attribute values you can use the method z_dEmp.

One way is to create a start sequence and then to re-sequence the order depend on your restrictions.

 

Steffen Bangsow
freelance simulation specialist  
web: www.bangsow.eu
mail: steffen@bangsow.net

Re: Sequence heuristic by Method

Experimenter
Experimenter

Thank you really much for your quick response.

 

I think your example model does exactly what I need (if I interpreted all the methods correctly). For me it is quite difficult to understand all the methods in detail.

 

I adjusted the model a bit and added my own distribution and the restrictions it has to comply to (distances). When I run the model again it fails to create a new sequence. The method will keep running. As I mentioned, I do not know exactly if I have to make any adjustments and where to make them in the method. 

 

Could you take a look at the adjusted model to see where things go wrong, and could you give some advice on how to change things?

 

Thank you in advance.

Re: Sequence heuristic by Method

Gears Esteemed Contributor Gears Esteemed Contributor
Gears Esteemed Contributor
my method is unable to create your sequence. This happens, if there are too many restrictions or the portions of the parts in the sequence have no relation to the restrictions.
The distance is a minimum distance, I try to find one element from the remaining sequence, that fits into the sequence, without violating the given restrictions. If there is no element, the sequence cannot be created.
Steffen Bangsow
freelance simulation specialist  
web: www.bangsow.eu
mail: steffen@bangsow.net