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How to Diagnose Loops In Planning Causing Plan Failures (Doc ID 1414433.1)

Last updated on FEBRUARY 06, 2023

Applies to:

Oracle Advanced Supply Chain Planning - Version 12.1.3 and later
Information in this document applies to any platform.


To Diagnose BOM / WIP / Sourcing Loops in Planning causing Plan failures.


To Diagnose BOM / WIP / Sourcing Loops in Planning causing Plan failures.

We have never supported Loops for MRP or ASCP planning. This has been the case since inception of MRP many years ago. And this continues in ASCP planning.
When you have sourcing loops, BOM Loops and/or WIP Loops, then the plan output cannot be guaranteed to be accurate and since they are not supported, we break the loop and attempt to continue planning successfully.... However, there are times when trying to break the loop will use a lot of memory and cause a plan failure.

-- SO --

  1. Loops are not supported at any level - Discrete or OPM for
    - ASCP planning
    - MRP planning or Supply Chain Planning
    - Inventory Planning
    - Rapid Planning
    - Service Parts Planning
    - Distribution Planning (except Inventory Rebalance Sourcing rules mentioned below)

  2. This applies to BOM Loops at any level.

  3. WIP Loops - generated from BOM's with Loops
    OR (most likely) IF you define a WIP job manually that uses a loop (usually a non-standard job for re-wrok), then the expectation is that the MRP net quantity = 0 at header level and/or the Component Net MRP flag is unchecked to avoid the loop condition.

  4. Sourcing Loops are not supported and you must make sure that any sourcing that is assigned at higher level - example would be Item level (or Instance level in ASCP) that for the ultinmate sourcing org where you buy or make the item, that you have an item-org level sourcing rule that defines the make or buy level and it is assigned at the item-org level in the assignment set used by planning.
    Exception is new Distribution planning in R12.x (this is NOT old style DRP planning in Supply Chain Planning)

  5. When a loop is detected it will be reported in the log files for one of the following -
    Memory Based Snapshot OR
    Memory Based Snapshot Worker log OR
    Memory Based Planner (Pegging loops)
    AND SO
    We do NOT guarantee that the output of the plan will be accurate and until the loops are removed.
    SO -- ALL Loops must be removed before we will consider investigation for plan results that show:
    A) Inaccurate inclusion of items in the plan
    B) Accuracy of the Plan results.

In Distribution Planning, which is first released in Release 12, we have introduced the concept of supporting Circular sourcing loops which are part of a distribution sourcing and in ASCP  / Sourcing / Sourcing Rules - you can define rules that use "Inventory Rebalance" check box for circular sourcing. This is discussed in the R12.x Advanced Supply Chain Users Guide in Chapters that discuss Distribution Planning. Please be aware that this type of sourcing is only applicable to Distribution Planning in Value Chain Planning applications and does NOT apply to standard Supply Chain Planning - DRP plans



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In this Document
 Section 1 : Bill Of Material - BOM Loop
 Section 2 : Work In Process - WIP Loop
        WIP Loop # 1 : [ Component same as Assembly in Job ]
            WIP Loop # 2 : [ WIP Job Material Reqmts Don't Match Bill Of Material Setup ]
               WIP Loop # 3 : [ Component same as Assembly item ]
                 WIP Loop # 4 : [Includes SQL for OPM]
 Section 3 : Sourcing Loops
       Sourcing Loop # 1 : [ Related to Sourcing defined in PR or PO ]
               Sourcing Loop # 2 :
 Known Issues

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