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Scheduling for 4 machines with similar task

7 replies [Last post]
Casual Max
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Hi guys, 

I have just found this forum but I'm not sure is this the correct platform to ask such question. If it is, great! If it's not, I would appreciate it if someone would redirect me to the correct platform.

 

My problem:

I have 4 machines (Total 6) that perform a similar task and each of the machine has a similar life before they will be sent for maintenance. Let's say each machine will have to produce 35 items before sent for maintenance which will take 5 days before they can be re-used. And each day, they need to produce 6 items alltogether. When one machine goes for a maintenance, backup machine will be used to replace that until it produce 35 items which will be then sent for a maintenance too. One of the constraint is that the production cannot be interrupted i.e. the machines cannot be sent for maintenance at the same time, only 1 at a time, hence usually one or two machines will be pushed to produce more items. 

I have been doing this scheduling manually: drafting no of items for each machine day by day format and this takes time. I wonder if there's an algorithm or a faster method to do this?

Thanks in advance guys!

 

 

Replies

Zoltan Palffy
User offline. Last seen 5 hours 56 min ago. Offline
Joined: 13 Jul 2009
Posts: 1824
Zoltan Palffy
User offline. Last seen 5 hours 56 min ago. Offline
Joined: 13 Jul 2009
Posts: 1824

display email and I will send pdf both pages 

Zoltan Palffy
User offline. Last seen 5 hours 56 min ago. Offline
Joined: 13 Jul 2009
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I have the solution this is page 1

5349
4_machines_1.jpg

Rafael Davila
User offline. Last seen 20 hours 17 min ago. Offline
Joined: 1 Mar 2004
Posts: 4461
  • I understood you do not want to perform manual assignments, otherwise the solution will add nothing to your request.
  • The statement - I have 4 machines (Total 6) can be confusing: I understood 4 machines (6 items/day), when one in maintenance each of the remaining 3 will produce 2 items/day each machine, when all 4 available 2 will produce 2 items/day each machine and 2 will produce 1 item/day each machine.  It does not makes sense to me that fractions of unit production will be shared on a production line.  In such case a machine will produce either 1 or 2 but not something in between. Then the production cycle is not a fixed number and can be as low as 18 days (17 days 2 items/day + 1 day 1 item/day = 35 items in 18 days). Please confirm.
    • For such automatic resource assignment some advanced functionality such as consumable resource consumption, consumable resource production and automatic skills replacement might be required.  Not many software have such functionality and most will require manual resource assignments.
    • Download link to sample model with automatic assignments.

    • I suggest considering other what-if scenarios such as increasing the maintenance time to 6 or 7 days, it might be it will still meet the requirement for maximum units produced before maintenance is required without delaying production activities after renewable and consumable resources leveling.  Also other resource prioritization per activity should be considered as to better control how machines are selected.

Best Regards,

Rafael

Zoltan Palffy
User offline. Last seen 5 hours 56 min ago. Offline
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I did not get the PM

Casual Max
User offline. Last seen 22 weeks 4 days ago. Offline
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Thanks, I have sent PM to you with my email address. Let me know if you did not receive it, I'm not really familiar here 

Zoltan Palffy
User offline. Last seen 5 hours 56 min ago. Offline
Joined: 13 Jul 2009
Posts: 1824

I have your solution if you give me your email I can send you the pdf. The controlling factor is that the maintenance can only be on 1 machine at a time.

the machines together have to produce 6 units per day. Therefore 4 machines * 1.5 units per machine per day = 6 units per day

if the machine has to produce 35 units before it can be maintained then 35 units /1.5 units per day = 23.33  days before the machine has to be taken out for maintenance in my exercise I rounded this to 20 days.

you are correct in that after the 20 days or 35 units prodiuced and machine #1 goes down for maintance means that machine #5 and machine #6 comes on board they will have to double their production at 3 units per day for 5 days until you get machine #1 back from maintenance, At that tiime you will have 3 working machines and the prodcution will have to be 2 unist per day per machine. Once you go thru the 1st round of maintenace then you should be ok. 

Like I said I have a pdf to send you that show the production and maintenace for each machine all I need is your email adress.