Scheduling for 4 machines with similar task

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Casual Max
User offline. Last seen 3 days 11 hours ago. Offline
Joined: 11 Jan 2018
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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 10 hours 28 min ago. Offline
Joined: 13 Jul 2009
Posts: 1630

I did not get the PM

Casual Max
User offline. Last seen 3 days 11 hours ago. Offline
Joined: 11 Jan 2018
Posts: 3
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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 10 hours 28 min ago. Offline
Joined: 13 Jul 2009
Posts: 1630

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.