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Handling of MUs according to attributes

Pioneer
Pioneer

Hi Community members,

 

I try to develop a simulation model for a production process of metal parts. I've gathered historical process data of 2015 and would like to work with it in order to validate the model upfront (as recommended in my first post here). 

 

I have a source list with various attributes for each order/MU. See table "lieferliste_intern" below:

08-01-_2016_14-24-29.png

 

I would like to handle each order according to its attributes. Therefore the following questions arouse:

 

1. How do I forward each order/MU to the right SingleProc that is saved in its attributes?

I hope someone can help me with an easy method.

 

2. Processing time should be changed according to the attributes as well. I use a method in entry control of every SingleProc, is that the right approach?

is
do
	?.bearbeitungszeit:=@.ProcessingTime*@.LotSize;
end;

3. What do you suggest in order to model the yield and waste of each order? (See attributes in the table above) Each turning machine processes the defined lot size but the amount is reduced by the amount of waste parts.

 

Thank you in advance

 

Best Regards

 

08-01-_2016_14-39-57.png

 

13 REPLIES

Re: Handling of MUs according to attributes

Phenom
Phenom

Re: Handling of MUs according to attributes

Pioneer
Pioneer

Thank you simulator, embarassing that I've missed the topic.

 

Is there a way to solve it with a method also? Just asking because by using connectors the model becomes very confusing.

 

10-01-_2016_17-30-34.png

 

Does anyone have suggestions for the question below?


@Jan_B wrote:

3. What do you suggest in order to model the yield and waste of each order? (See attributes in the table above) Each turning machine processes the defined lot size but the amount is reduced by the amount of waste parts.


Thanks a lot

Re: Handling of MUs according to attributes

Phenom
Phenom

 @3 have a look at this singleproc  tab

 

Unbenannt.png

Re: Handling of MUs according to attributes

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Hi,

 

You can hide the connectors frame-by-frame. Or you can program an exit-control for the buffer, but connectors are more robust in general.

 

Regarding yield, there are some basic tricks you can use. 1) Use an attribute for the MU that tells if it is a rework/waste part or not. 2) Determine this yield with a random variate. 3) Use exit strategies (or exit controls) that use this attribute to determine the next station for the MU.

 

It depends on the case how you model the causalities. If yield is an attribute of a machine, you can set a yield percentage in an attribute and us that in step 2. This way you can also study the impact of improvements.


Gert Nomden
Senior Consultant | Tecnomatix Product Manager
cardsplmsolutions.com

Re: Handling of MUs according to attributes

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

The suggestion of @simulator works, too, of course...


Gert Nomden
Senior Consultant | Tecnomatix Product Manager
cardsplmsolutions.com

Re: Handling of MUs according to attributes

Pioneer
Pioneer

Thank you for your quick responses.

 

I've used the ALT-key to structure the connectors less confusingly.

 

Thanks simulator and Nomden for the hints in order to model the waste. I've just started with the model and  I would like to use historical data in order to validate it upfront as some users suggested in another post. Therefore I would like to use the predefined amount of waste and times etc.

 

The problem now is that I've modeled orders coming from a delivery table as MUs with predefined lotsize and waste as their attributes. I've put some thoughts into a conceptual model in Visio (see attachment) to make it clear and understandable. Is this the right approach?

I've marked text red where I don't know how to transfer it into Plant Simulation (I am sorry, still a learner) Hope someone can help me with my problems.

 

Thanks a lot!

 

Re: Handling of MUs according to attributes

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Well, my consideration would be to see if it is enough to model the batches as a single MU, instead of all the individual parts. Since it looks like the batch remains a batch throughout the process (yes, it is unboxed for a machine, but then it seems to be re-boxed again when completed), it would make the model simpler/faster. You can always split them later on if the pieces in the batch are treated individually.


Gert Nomden
Senior Consultant | Tecnomatix Product Manager
cardsplmsolutions.com

Re: Handling of MUs according to attributes

Pioneer
Pioneer

This was my consideration also.

However, by modeling the batches as single MU, I don't know how to handle processing times and waste correctly because the original lotsize from the source decreases by the amount of waste parts. 

Re: Handling of MUs according to attributes

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

I think it is pretty simple. You use a formula to calcualte the processing time, based on the attributes of an MU (lot size * time per part). If there is waste in some step, you reduce the lot size and the later processes reduce their time accordingly.


Gert Nomden
Senior Consultant | Tecnomatix Product Manager
cardsplmsolutions.com