Sorting and Stacking multi products

Hello,

I am a newbie with Flexsim which just got installed on my system. I have gone thru the user guide and manual but still haven't got any clue to do this. I do need the community's help to give me a kick start.

- The model that I have do involves 41 products coming in randomly to a sorting station. Those 41 products are not coming in equal numbers. There is a certain ratio to comply.

- The products will be stacked on 40 stacking positions ( like a rack with 1 bay and 1 level). Only the same product typle will be stacked to "x" numbers. The products won't mix in the same stack. When the stack is full, the operator will clear them.

- The stacks are not assigned to each product. The machine will place the products in any available spot of 40.

My problems are

1) How to get the Source configured with 41 products coming in with certain ratio?
2) How to make the transporter stack only the same products in the same spot at a time?
3) The racks will not be assigned with specific product number.

Thank you in advance,
Simon

Simon,

Welcome, I'm always glad to see new users join the forum. I looked but couldn't find any information about you in your profile. Flexsim has distributors all over the world and depending on where you are located I'm sure that there is someone close by that would like to help you get trained in the software and if you needed it hands on help with your first model. Here in the U.S. we have a specific program that we offer to help people get started on their projects.

The reason I bring up training is that it does not appear that you have had it; also, training will answer the questions that you are going to have in addition to the ones you have posed here.


As to your questions, I would start by not using a rack. I'll explain why later on.

The answer to your first question can be found by going through the first tutorial in the User's Manual (Help -> User's Manual -> Tutorials -> Lesson 1). Specifically you will want to look at Step 4 where they create 3 random item types. The only thing you will need to change is the 3 to 41. I would go into more detail but I don't think that I would be as good as the tutorial is.

The answer to questions 2 and 3 is that you don't make the transporter do anything at all. Task Executers (Transports) in Flexsim do not define the flow in the model. That is done by the sending or receiving objects depending on whether you are pushing or pulling. In your case I would recommend pushing. The reason for this is that there is a pick list option called "Matching Itemtypes" that specifically solves this problem. This is why I recommended against the rack. Placing items in specific bays or levels in a rack is done in triggers on the rack that don't have that pick list option.

I hope that this helps you get started on your model.

Good Luck,
Brandon

Brandon,

Thank you.
We used to have Flexsim Licence in the past but no body used it and got expired some time ago. Recently, our department decided to use the simulation software and I am the point man to do this. I had some experience with Arena several years ago and thought it is going to be similar but i am seeing more good stuff with Flexsim.

By the way, I am in Nova Scotia, Canada. Rachel sent us the schedule of upcoming training sessions but I don't think the current work load and the current economic situation would allow me to have that.

The matching item types works. That's great. Next, my incoming products are random but they have their own specific inter-arrival time ( I think that will address the product mix by volume, right? Higher volume product will have shorter inter-arrival time.) I am thinking of using "By Global table lookup" from the pick list. Is it possible? If so, the col-1 should have items and col-2 should have inter-arrival time, am I right?

And if I use that Global table look up, how can I still have an option to have statistical distribution for each item type? i.e. item1 has normal distribution, item2 has exponential and item3 has uniform etc.

Last in this reply but not least, any good website or ref. material for me to read for further understanding of Flexsim vbcodes?

Again, Thank you,
Simon

Simon,

First, Flexsim is based on C++ and uses Flexscript so vbcodes won't apply; and the best resource for Flexsim and Flexscript is the one you are using. If you can't find the answer to your question in another post and you have a very specific question and are willing to work a little, you can get a really good answer from another user here on the forum.

If I were you (new and not looking to write lots of code) I would use a visual tool as a container and put one source for each product type in the visual tool and connect each source up to a single queue. One source for each product is a lot of sources but it is much more simple. The reason for the visual tool is that you can give it any shape you want and then hide its contents so that it only looks like one object.

Why use a global table? If you are trying to keep all of the data in one place then this makes sense and there are many options for how to link this to the sources. The easiest but slowest is to make the table cells text and store the function there. Then in the inter-arrival time trigger you can call executefsnode() on the table cell. Another option would be to make a custom GUI to get to the inter-arrival time of each source, but this is a more advanced solution.

Someone else may have a more simple solution using the pick list options. I typically find it easier to just write the code than find the pick list option I want, but his comes from using Flexsim back in the day when there weren't really any pick list options to choose from.

Good Luck,
Brandon

I agree with Brandon that the best way to learn Flexsim is to get at least the Flexsim 101 training. As far as your requirement to model statistical distributions in global tables, this can be done easily by storing the distribution function as a column in a global table. Then simply you read the row,col combination and use the executestring(gettablestr("tablename",'row,col)) flexsim command to simultaneously retrieve and execute the distribution function in one simple step.

I know this works since this is what I am using to model the complexity of processor's varying efficiency which is dictated by an emperical distribution. For example: situations like - the processor is 90%-95% efficient 70% of the time it is running, it is 75%-90% efficient 30% of the time and so on and so forth.

In this situation, you really need a nested emperial distribution with a standard distribution like duniform,dnormal etc.

Hope this was helpful to you and good luck with Flexsim modeling.

Related thread here.