Gaps between operations

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Posted on by HenkeNord

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We have problems that the first operation in our routes, material picking, starts many days before the second operation, when running master planning (job scheduling mode). This makes the material being piled next to our machines for days which isn't desirable. The material is linked to the first operation (end). The problem occurs when the resource in the second operation is full. I have tried with different settings on Link type (Soft, Hard and Blank) with no difference.

Example of jobs after running master plan, as you can see the first operation - material picking start 23/9, and the second start 15 days later, which isn't ok.

0511.Jobs.png

First operation resource workload

Second operation resource workload

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HenkeNord 465 on at

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Just to clarify, we use 2012 R3, CU9.

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Fredrik Sætre 12,644 on at

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Hello again Henrik,

In what direction are you planning?

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HenkeNord 465 on at

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Hello Fredrik, again...

It's during MRP so it should be backwards.

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Fredrik Sætre 12,644 on at

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Are you doing a full recalculation or just net update? Didn't the second resource have unlimited capacity?

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HenkeNord 465 on at

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We always do a full Regeneration. The second resource does not have unlimited capacity (the first one has unlimited).

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Fredrik Sætre 12,644 on at

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Could you try swapping the resources around, so that the limited one is primary?

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Weaveriski 23,620 Moderator on at

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There was a known limitation of work centres (for finite I think) which was 32 to check for scehduling and in its logic looking it would start to produce gaps - as a test you could set it all to infinite and then you have no gaps. The link type did nothing. I encountered this back with the release of 2012 so it is a long time ago, fortunately the client only set the bottleneck resources to finite. I have tried to find the conversation with Microsoft but cannot.

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HenkeNord 465 on at

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Sorry for late reply.

I tried with unlimited capacity for the second resource and after that the didn't occur, but the capacity load doesn't look nice...

Could the problem occur due to change of planing direction since the second resource is full. The system would start the first operation as soon as possible and since the resource is full there will be a gap until free capacity is found.

We really need limited capacity in our resources, do you think there is a bug on the link-function or shouldn't it help in this situation?

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Fredrik Sætre 12,644 on at

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Maybe create a support case to Microsoft on this through your partner. That should elevate any missing elements.

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Mr W 77 on at

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Hi, I’m facing the same problem that you have described.

Did you find any solution to this?

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