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Evaluation of cyclic behaviour

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Hi everyone,
I am facing a new challenge.

In my standard model, when I don't have specific requests, I provide as output values WIP, throughput and lifespan for each part produced by the line. To do this I look at the drain statistics. In this way the throughput at the end of the run is a mean value.

Now I have a new line which produces 6 different parts, each one with different cycles time and dedicated machines. Two batch of different parts enter into the line contemporary.
Analyzing data, it is pretty clear the line behaviour is cyclic: the throughput is not stable, on the contrary it goes up or down every X day depending on the batch size.
With this line I can't run the model, let me say, for 20 days, look at the throughput per hour and obtain the annual production (YearProd = tph*workingdays*workingHoursPerDay). And I can't neither run the model for 365 days to test every solution, especially when using the experiment manager.

Do you have suggestions to handle this problem? How can I extract meaningful output data?

Regards
Alessio

4 REPLIES 4

Re: Evaluation of cyclic behaviour

Gears Esteemed Contributor Gears Esteemed Contributor
Gears Esteemed Contributor
I guess there are different ways:
- compare the output numbers of all parts with the planned output (see also detailed statistics of the drain)
- equivalence numbers: if you want to create one figure to observe the performance of the system, you could calculate based on a standard part a multiplier for each product to take into account different production efforts (e.g. in the bottleneck operation). With this multiplier you multiply each produced part and get the output as weighted units.
Steffen Bangsow
freelance simulation specialist  
web: www.bangsow.eu
mail: steffen@bangsow.net

Re: Evaluation of cyclic behaviour

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Legend

Thanks Steffen.

I can't compare my output with the planned one because we are in the project phase, the line not exists yet.

 

I don't understand your second point. My problem it is not acquire data, but it is understand how many parts the line is able to produce every year, without (of course Smiley Happy) run a simulation for 365 days.

With a line which stabilizes its behaviour after X days (warm-up period) no problem, but with this one...Smiley Frustrated

I don't know if my problem is clear (or maybe I didn't get your answer?)

 

 

Re: Evaluation of cyclic behaviour

Gears Esteemed Contributor Gears Esteemed Contributor
Gears Esteemed Contributor

for the several products you should also have plan data (e.g. production schedule for each product), if you record the output per week/month for each product, you should be able to calculate with the average values of the weekly/monthly output the output per year for each product.

 

You can use a generator for create such statistics, simular to this topic:

 

http://community.plm.automation.siemens.com/t5/Plant-Simulation-Forum/Record-Production/m-p/356026#U...

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

Re: Evaluation of cyclic behaviour

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Legend

Yeah, in this moment I'm using a source with the percentage creation strategy, but probably without a scheduling is not possible understand if the lines met the requirements or not.

The main problem is still here, I need to run a model for several weeks/months depending on the scheduling, but I guess there aren't alternatives.

Thank you.