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Constraint in Experiment Manager

Solution Partner Valued Contributor Solution Partner Valued Contributor
Solution Partner Valued Contributor

Hi guys,

 

I am busy with a Buffer Allocation Problem (BAP) with the following set up:

BAP.JPG

What I need to do is determine the optimum buffer size to maximize throughput per hour and minimize WIP. The only problem is that the sum of all the buffers (Buffer1.capacity + Buffer2.capacity etc) has to be equal to 10.

 

I have been looking at the advanced settings of the experiment manager and it seems that the Rules could use but I can't figure it out.

 

Also, is it possible to easily set up a weighted-multi-objective experiment in Experiment Manager? i.e Try to maximize throughput per hour and minimize WIP (at the same time) and return the optimal buffer size combination based on the respective weighting? 

 

Thanks!

5 REPLIES

Re: Constraint in Experiment Manager

Legend
Legend

That sounds like something you should use genetic algorithms to do.

Re: Constraint in Experiment Manager

Siemens Phenom Siemens Phenom
Siemens Phenom

Hello HermiasH,

 

there are only 84 possibilities. Therefore a genetic algorithm ist not recommended.

 

 local tab := ExperimentManager.ExpTable;
tab.delete;
for local x1 := 1 to 7 loop
for local x2 := 1 to 7 loop
for local x3 := 1 to 7 loop
if x1+x2+x3 < 10 then
tab.writeRow(1, tab.ydim+1,true, x1,x2,x3,10-x1-x2-x3);
end;
next;
next;
next;

Regards,

Peter

Re: Constraint in Experiment Manager

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Hi HermiasH,

 

You can include multiple output values into your model. Weighting is generally not really a good idea, since weight are always arbitrary.As soon you have a multi-objective situation, multiple outcomes may have the same objective value.

 

You can write your own evaluation method in the ExperimentManager under Tools>Advanced settings...>Use evaluation method.

 

While you do not have that many experiments, you can easily select suitable canidates around the optimum. One more formal technique for this is Data Envelopment Analysis.

 

Regards,

Gert Nomden


Gert Nomden
Senior Consultant | Tecnomatix Product Manager
cardsplmsolutions.com

Re: Constraint in Experiment Manager

Solution Partner Valued Contributor Solution Partner Valued Contributor
Solution Partner Valued Contributor

Thanks Peter!

The buffers can be 0 so I adjusted your coding as follows: (it works perfectly)

 local tab := ExperimentManager.ExpTable;
 tab.delete;
 for local x1 := 0 to 10 loop
   for local x2 := 0 to 10 loop
	   for local x3 := 0 to 10 loop
		  for local x4 := 0 to 10 loop
        if x1+x2+x3+x4 = 10 then
      	tab.writeRow(1, tab.ydim+1,true, x1,x2,x3,x4);
        end;
       next;
    next;
   next;
 next;

 I am still looking for the best way to pick an optimal solution due to the multi-objectivity of the model. Any suggestions?

 

Re: Constraint in Experiment Manager

Solution Partner Valued Contributor Solution Partner Valued Contributor
Solution Partner Valued Contributor

Thanks Gert! That is what I was looking for Smiley Happy

Do you possibly have an example Method?