The backflush logic - basics

[Former Member]

As a new member of the PP team, at first I faced with problems in understanding the logic of backflushing. I was aware of the places where it can be set, but I could not imagine the effect of it in practice. Now I would like to share with you the basic effects of this setting.

The most important facts:

• if a component is set as backflush, then this component will be posted within the confirmation
• if you confirm e.g. operation 10, then the system checks which components are assigned to operation 10 and then choose the material, which is assigned and backflush this material post to goods movement
• it is important, which components are assigned to which operation, we need to define this allocation
• system proposes automatically both components from the assigned BOM and if no connection is added here, the system is automatically added to the first valid operation (New Assignment button)

Let’s start with the example! Here is my material BOM, which consists of a semi-finished material (MITYU_TEST2) and raw materials (one discountinuated and two alternatives):

As a first step, we should check the assignments in the routing:

• CA02->operation overview -> Comp.Aloc button -> New assignment

We have four possibilities to define whether a material should be backflushed:

    1. manually (CO02 -> component overview -> backflush flag)

    2. material master (MM02->MRP2 tab)

- always (CO02 -> component overview -> backflush flag is set)

                        - depend on workcenter (CO02 -> component overview -> backflush flag is not set)

Important: if you change the material master after creating the order, the existing order won’t get updated, you have to reread the master data (CO02 -> Functions -> Read PP master data

     3.  work center (CR02 -> Basic data -> Backflush)

                     - it has an effect on all material being assigned to this operation

     4. customizing of confirmation (OPK4 -> Generally Valid Settings -> Goods movements)

- if you set the indicator, the system displays all the components regardless of whether or not the backflushing indicator is set for the component in the order

- (in case of problems see note 1872575)

Prerequisits of backflushing:

     1. Setting the ‘Movement Allowed’ flag (CO02-component overview-details -> General data tab -> General Indicators -> Movement Allowd)

• if it is not set: not possible to post goods movements :!: even if the backflush indicator is set, because it has the highest priority
• backflushing does not automatically set this flag, it is set during the order creation
• setting the ‘Movement Allowed' indicator can only be carried out for a released order

     2. Either ‘Automatic Goods Receipt’ is set in OPKP or the operation has a control key, with ‘Automatic Goods Movement’

                - if you do not set this indicator then the control key of the operation decides how the automatic goods receipt is carried out

   

Basic example scenario:

• No ‘Automatic Goods Receipt’ is set in OPKP
• No control key has automatic goods receipt indicator
• None of the materials are backflushed
• No backflush in work center
• Goods movements flag is unset in OPK4

Confirmation in CO11

 

Scenario 1:

• set the ‘Goods movements flag’ in OPK4 (all other settings are fixed)

Scenario 2:

• set a control key with automatic goods receipt indicator

Scenario 3:

• set the ‘Goods movements flag’ in OPK4
• set a control key with automatic goods receipt indicator

Scenario 4:

• set a control key with automatic goods receipt indicator
• backflush (CO02 -> component overview -> backflush flag) for the alternative items and the discontinuated

I really hope, that my short demonstration helped you! :smile: