warehouse simulation-modeling 55 codes

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vassilis94s
Posts: 19
Joined: Monday 05 December, 2016 - 15:16

warehouse simulation-modeling 55 codes

Post by vassilis94s »

Hello,
I would be greatful if you could help me with the problem i face..First of all, i have to simulate a warehouse operation for my diploma thesis. In my case we have 55 different codes/products. I have made the model but i can not make it work..Firstly i have put 55 products joined with 55 sources..In this step i want to programm the sources to produce according to Economic Order Quantity for each product until the monthly demand is reached. For instance, source 1 produces products1 and we have EOQ=595 and we have to produce 1200..source 2 produces products 2 with EOQ=235 and we have to produce a total of 350..i want to produce in each cycle the EOQ amount and make loops until each code cover the monthly demand and then stop..how can we put sources in a raw and make them produce the EOQ and make loops?..We have a strict production line.. ex.product 1,product 4, product 13...i hope you understand what i mean..

We have 3 palletizing stations where products are headed after production. Before each palletizing station we have a queue. Each palletizing station is represented with an assembler.Each code matches with a specific palletizing station. There we assemble the pallet with products..We have two kind of pallets one 1,4x1,4m and one 1,2x0,8m..How can we put the right pallet size to assembler according to the product we have inside?..after each assember we have a queue where forklift come to load the pallet and store them to the warehouse. The warehouse is a ground one and it is designed and divited according to CAD for 55 codes. How can we program the forklift to understand where have to place each product?..Fifo must be served..Then another forklift will take product from warehouse and lead it to the exit where we have a queue and a sink..I want your advice about my model and how i can make it work..
Thank you for your help
User avatar
HarryBunnik
Posts: 362
Joined: Monday 07 February, 2011 - 11:22

Re: warehouse simulation-modeling 55 codes

Post by HarryBunnik »

Hello Vassilis94s,

I'm not entirely sure i understand what you try to achieve. I've made a small model trying to clarify what I understood. In this model I have a check on the OnExit trigger of my Source and this is checking, based on the order size and the EOQ, how many products should have been produced (so in the case of the 1200, I understand you want to product 1190, since that is the closest multitude of 595, or do you want to produce 1785, since then you can fulfill the order?). When there are so many produced, the source is closing down (see code). Of course this will have to be updated using a table out of which you read the order size, the EOQ and the number of products that already have been produced so you can have it create more then just one order.
Stop at EOQ.mod
(14.67 KiB) Downloaded 235 times

Code: Select all

Do(
  var([valProductionRequest], vbValue, 1200), {Use cells in table to make this more flexible}
  var([valEOQ], vbValue, 595), 
  
  var([valOptimalProduction], vbValue, valProductionRequest - Mod(valProductionRequest, valEOQ)),
   
  If(
    Output(c) = valOptimalProduction, 
    CloseOutput(c)  
  )
)
Is this more or less what you had in mind?

Your question about the pallet size is a bit tricky. What is determining which pallet size is used. Is that the next product waiting in the product queue? Are they created in a fixed order? I think you'll have to play with the Queue discipline on the pallet queue.

For the Advanced Transporter you'll have to work with the Offsets to place it at the correct locations (also see one of the Example models regarding the Advanced Transporter where this is done for the warehouse.

I hope this helps you further.

Cheers,

Harry
vassilis94s
Posts: 19
Joined: Monday 05 December, 2016 - 15:16

Re: warehouse simulation-modeling 55 codes

Post by vassilis94s »

Hello Harry,

Thank you for your responce. As for the EOQ this model is not what i mean. I will try to explain you so as to help me. I have 55 codes. We have to produce for each code a monthly amount which is determined by the demand.
code 1= 1200 parcels
code 2= 900 parcels
code 3= 450 parcels
code 4= 1800 parcels
.....code 55= n parcels
all of these must be served because is the average monthly demand profile for each one.
The production is done according to EOQ
code 1= 346
code 2=470
code 3=223
code 4= 740....
This algorithm we want to produce EOQ code 1 ,EOQ code 2, EOQ code 3....EOQ code n (first loop)
After the end of the first loop we have 346 from 1, 470 from 2, 223 from 3 etc..we make loops until we reach the monthly demand for code 1 1200, for code 2 470, etc. If the ammount overpass the 1200 for code 1 ,the rest works as the starting point for the next month..rest+346+346...
I hope you can understand what i mean..


As for the assembler..each palletizing station has been replaced by an assembler. There each parcel is assemble with a pallet. We have two kinds of pallets.The parcel is inserted the assembler right after the production from source and the pallets from 2 different sources. We have 2 kinds one 1,4x 1,4 and one of 1,2x0,8. I would like to know how each pallet can recognize the product inside the assembler and be inserted the right one to fit the product?

Let's say we have 55 different warehouses how the forklift can understand the product and put it in the right one?..
I have build the model my PROBLEM IS HOW TO CONNECT THE CHANNE;S AND MAKE IT WORKS..if you could give me an email to send you..I avoid to upload it here because it has perconal rights..
Thanks
User avatar
HarryBunnik
Posts: 362
Joined: Monday 07 February, 2011 - 11:22

Re: warehouse simulation-modeling 55 codes

Post by HarryBunnik »

Hi,

I've made an example model that is doing what you're describing on a smaller scale.
Community_Production.mod
(37.62 KiB) Downloaded 219 times
I've created a table in which I keep track of:

- The size of the order
- The EOQ
- The number of produced products
- If a line is active
- A pointer value to the correct source

The table is controlled from the Initialize atom. Here is set values back to 0 on Reset and fill the correct pointer values to the sources. NMote that the sources must be named Source1 until Source55 to make this work.

Then there is code on the OnExit that checks if a full EOQ is produced or that another Source must take it over. If another Source must take over, the function "FindNextProductionLine" (defined on the Function Editor takes over).

Code: Select all

Do(
  {Search for the row of the source in the table, using the pointer value of the Source}
  var([valEOQ], vbValue), 
 
  If(
    input(c) = 1, 
    Label([RowIndex], c) := TableFindValue(refProductionDetails, ptv(c), 5, -1)
  ), 
  Cell(Label([RowIndex], c), 3, refProductionDetails) := Cell(Label([RowIndex], c), 3, refProductionDetails) + 1,
  
  valEOQ := Cell(Label([RowIndex], c), 2, refProductionDetails), {Use cells in table to make this more flexible}
  If(
    Mod(Cell(Label([RowIndex], c), 3, refProductionDetails), valEOQ) = 0,
    {Start-up next source}
    Do(
      CloseOutput(c), 
      FindNextProductionLine(Label([RowIndex], c))
    )
  )
)

I hope this gives you some ideas how to continue. Do note that with a new month, you'll have to start all up again (OpenSource of row 1) and complete the administration (subtract column 1 from column 3).

Cheers,

Harry
User avatar
HarryBunnik
Posts: 362
Joined: Monday 07 February, 2011 - 11:22

Re: warehouse simulation-modeling 55 codes

Post by HarryBunnik »

As far as the other question goes, you can send me a Private Message, so I can have a closer look.
vassilis94s
Posts: 19
Joined: Monday 05 December, 2016 - 15:16

Re: warehouse simulation-modeling 55 codes

Post by vassilis94s »

Thank you very much for the reply. When i run the model for 5 scources only the product1 and product 2 runs smoothly. The other three run without the code we entered and produce randomlly. I have copied paste the code you entered..i would be thankfull if you could help me with that issue..
User avatar
HarryBunnik
Posts: 362
Joined: Monday 07 February, 2011 - 11:22

Re: warehouse simulation-modeling 55 codes

Post by HarryBunnik »

Have you updated the table named "ProductionDetails" to 5 rows and filled the first 2 columns with order size and EOQ?
vassilis94s
Posts: 19
Joined: Monday 05 December, 2016 - 15:16

Re: warehouse simulation-modeling 55 codes

Post by vassilis94s »

Ι have sent you a personal message..thank you a lot for all the help provided
vassilis94s
Posts: 19
Joined: Monday 05 December, 2016 - 15:16

Re: warehouse simulation-modeling 55 codes

Post by vassilis94s »

I have sent you once again..thank you for notifying me
User avatar
HarryBunnik
Posts: 362
Joined: Monday 07 February, 2011 - 11:22

Re: warehouse simulation-modeling 55 codes

Post by HarryBunnik »

To sort the production not on name of the sources, but on a specific given priority, I've made a small adjustment to the model I've provided earlier. Here
I've added a 6th and 7th column to the production table, in which a production order and source number can be given.

In the initialize atom, I then use the source number (which is placed in column 7) to search for the requested source. Then all is sorted on column nr. 6, allowing it to produce in a user given order. When you update column 6, simply press reset and all is sorted again in the correct production order.
Community_Production.mod
(37.92 KiB) Downloaded 214 times
Cheers,

Harry
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