PP/DS optimizer creates unnecesary gap when considering secondary resource

[Former Member]

Hello experts,

I have the following scenario

Materials:

     HALB: 157943

     FERT: 157944

Resources

     LIN_BAS

     PRO_BAS

     CarboC

The recipe for the FERT consumes the HALB in LIN_BAS and uses a secondary resource called CARBOC during the entire process. The Halb is produced in PRO_BAS.

The issue is that when we run the optimizer it delays the FERT order for a period of time equal to the time it uses the CARBOC. For example: the FERT order lasts 8 hours and the CARBOC is used during those 8 hours  So if the HALB order finnishes at 18:00, the FERT order starts until 2:00 of the next day. This happens even when there is only one order for the FERT. I attached an image with the optimizer results.

What possible explanation could there be for this?

[renato_parise]

Hi Mauricio,

Check your activity relationships. If is End-Start, for example.

BR, Parise

[Former Member]

There is no relationship between the order for the FERT and the order for the HALB since the gap is produced between two recipes. I know how to chek that relationship between 2 phases of a recipe but how do I set it between 2 different recipes?

[renato_parise]

Hi.

you could checking your PPM or PDS to see this activity relationships.

[Former Member]

Hi Renato thanks for your help.

The problem is with container resources!

I checked the PDS and there is no relationship there either. But I'm using a product storage definition which stores the HALB during the order to produce the HALB and then the order to produce the FERT consumes the material from the tank. I didn't mention this to simplify the question but after you suggested I should check the PDS it occurred to me that the storage defintion implictly realtes both PDSs. I attached an image of the result of the optimization showing the tanks. The product flow is set to fill the tank at the start of the operation.

So I decided to test what happens if I remove the container resources form the scenario and after I did the optimization ran smoothly and there was no gap between the orders. I also tried removing the secondary resource and leaving the container resource (CARBOC) and again the optimizer ran smoothly.

But I can't understand how the container resource relates to the secondary resource. The container is assigned in the materials tab of the recipe while the secondary resource is assigned in the secondary resources tab of a phase in an operation. Any ideas of the realtion between container resources, product storage definitions and secondary reosurces?