I have a problem with routing. In our production, one item has a route with 4 operations. There is no overlap in our operations. We have a line based production..(one item enters first operation machine, when 1st opr. ends it goes to second operation machine and later 3rd and fourth operation machines.).But in order based production planning(tisfc1401m000), it plans production for 100 items as, first make first operation of 100 item in first machine, and take these 100 items and make the second operation in second machine. But in real, this is wrong. Because when first operation of one item finishes, second item comes to first machine and item, first operation finished, goes to second machine. Can you help me? What can I do to prevent this mistake?

Hi Zargon,

there is no chance to get exacly what you want. But if you work with overlap it properly will be better than before especially if your lot size does not vary too much.

The meaning of overlap in routings is that two operations are carried out partly at the same time. Overlap of 95% means that the next operation can already start when 5% of the lot size is finished in the operation before. Thus you need to set up your overlap to (1-1/x)*100% where x is average lot size. For instance if your average lot size is 50, overlap should be set to 98% because you can start the next operation when 1 piece = 2 % of the operation is finished.

You could also set overlap to 100% and insert dummy operations between every operation (overlap = 0%, without costs but only with the operation time of real operation before) ... Please understand that I do not want to continue to develop this idea. It works but I do not like it.

I think that this answer will not satisfy you entirely but I do not have a better solution.

Yours Jan

Thanks Jan,

I upload the schema of our production line. Our lot number vary too much according to orders. Also as you can see from the picture(opr1.jpg), 2nd machine has to wait first machine to operate the item.

I want to see order based production planning (tisfc1401m000) schema as in the picture I attached (opr.jpg). But when I give a operation overlap in route ( something like 49%), baan gives a result as in the second picture,I attached (baanplan.jpg). How can I solve this problem?

Thanks again for your help Jan.

Hi Zargon,

I have already met this problem when I have set up my test data. In my case the second operation was by far earlier ready than the first. I have set much more overlap and I had to notice that Baan does not check the data from this logical aspect.

There are two solutions

1. You can set the cycle time of all operations to the longest time. Anyway the machines are probably fully occupied with this operation and meanwhile not used for other purposes.

2. You can insert dummy operations without cost and just with the time difference.

From logistical point of view I would prefer the first solution. But you need to talk with your controller about the cost aspect because your item will get more expensive. In my opinion this is even right but many controllers think different because the machine is occupied but not used (this approach is also right).

Once again there is no nice solution.

Yours

Jan

Isn't there a option to input overlap in qty?

5.c does have a option to maintain 'Transfer lot qty' and the start date/time of the 2nd operation is correctly calculated by the system considering the completion of the first lot of the 1st operation and set-up time of the 2nd operation.

The 2nd machine will always remain occupied even if its cycle time is less and I don't think there should be any problem with the controllers.

Can I solve my problem with pull notes? Can anyone give me any information about Pull Notes in Routing?