Influencing the ATP check in APO
When running the integration model to transfer ATP customising to from ECC to APO various fields are sent across the CIF. Checking group becomes check control and is used to determine which horizons are used. Together with the document item categories this becomes the Scope of Check.
If you think of the Scope of Check as a filter for what is included in the ATP check, then what activities ATP will actually perform is governed by the Check Instructions. The check instructions specify the different steps to be accessed in the ATP check and in which order. If your requirement is to run different types of ATP check for different products (for example a check for one group of products with using RBATP and for another group of product using Product Allocations) then it is necessary to use more than one set of check instructions.
There are several different ways to enable the ATP check to access different check instructions but instructing SAP which method to use comes with added complexity.
The diagram below graphically represents the different options available and further details are underneath:
Determining the Source using transaction OVZI
Once an Item Category has been assigned to a schedule line category using table VOV5 it appears in OVZI. Table OVZI is used to determine which of the options listed in the graphic (Fig.1.) are used.
- If the source is set to 0 then the row is ignored in the table. This applies to strategy 1, 2, 3 and 4 from the graphic.
- Source 1 applies to strategy 4, or if MRP type is empty, also strategy 5.
- Source 2 is as in source 1 but with an additional check of the allowed requirements type.
In addition to the determining the Check Instruction from Requirements Type the following options are possible:
Option 1. Checking Rule using Document Type.
This is the APO equivalent of the ECC Checking Rule and is hard coded to match the document type (sales order, delivery etc). New document types can be custom created and therefore access different check instructions. SAP standard document types are hard coded to a Checking Rule and cannot be changed.
Option 2. MRP group via Checking Rule.
It is also possible to use new MRP groups in transaction ‘OPPR Define MRP Group’ to access different Checking Rules.
OVZG Define Requirements Class
OVZH Assign Requirements Type to Requirements Class
OPPT Define Strategy Group
OPPS Assign Requirements Type to Strategy Grou