PPM Substitutions 
Purpose
Along with
Calling Production Planning and Detailed Planning (CTP) you can reflect the production methods and depth of production in a rule using PPM substitutions. You can save several
Production process models (PPMs) for a location product in a PPM substitutions procedure.If a PPM is checked, Production Planning and Detailed Scheduling returns the information if the complete quantity can be confirmed. If the complete quantity cannot be confirmed according to the parameters in the calculation profile, no confirmation is returned and the next PPM is checked. The PPM substitution that can be 100% confirmed as the first substitution is returned in the rule evaluation. This only refers to the quantity, however; the date can be postponed here.
Prerequisites
You must have configured the call to Production Planning and Detailed Scheduling. For further information see
Capable-To-Promise (CTP). We recommend that you configure the call to PP/DS via the location determination activity. This guarantees that an ATP check can be carried out when a PPM is missing, without PP/DS being called.
You created a PPM substitution procedure. From the SAP Easy Access menu you chose Master Data ® Rule Maintenance ® Integrated Rule Maintenance ® 
PPM substit.proced.
- The first three fields (location, product, level) are obligatory. The PPM name field can remain blank.
- You can enter several PPMs per location product.
- The level number defines how the results list of a rule should be sorted.
- You included the PPM substitution procedure in a rule whereby the rule can only allow one substitution. For further information see
Restricting the Number of Substitutions.
You defined whether or not the PPM substitution procedure should work with a substitution procedure.
- PPM substitution procedure using substitution procedure (standard case)
If the system is to find PPMs for the substitutions, then the rule must contain other substitution procedures in addition to the PPM substitution procedure. The location products in the PPM substitution procedure must match the substitutions in content.
- PPM substitution procedure without substitution procedure
The PPM substitution procedure normally always needs another substitution procedure. You can, however, work without an additional substitution procedure if you have configured the Start immediately rule in the
check instructions. You maintain the check instructions in Customizing for the Advanced Planner and Optimizer via Global ATP ®
General Settings ® Maintain Check Instructions.The rule evaluation is then carried out immediately and only on the generating requirement. Ensure that a PPM is maintained for the corresponding requested location product.
- You set the Rules-based ATP indicator in the check instructions.
- You created a
rule control that defines the evaluation of several procedures (a substitution procedure and a PPM procedure). In this rule control you also selected a substitution level for the PPM substitution.
Process
In the following process, product allocation is treated as a basic method.
- A location product list is created from the procedures given in the rule. This can either be a
location determination procedure and/or a
product substitution procedure or alternatively, a location product substitution procedure. The sequence of the location products is calculated via the
rule control of the current rule, taking the requested location product into account.
The PPM substitutions are built on the basis of this defined location product list in the second step. This means that if a location product is missing in the basic quantity it is not included in the check, even if there is a row for it in the associated PPM substitution table. For every location product of the basic quantity the PPM substitution procedure is searched for suitable entries. (Suitable entry means the same location product). If no suitable entry exists within the PPM substitution procedure this location product is removed from the basic quantity and not checked. If one or more suitable entries exist in the PPM substitution procedure, one or more complete substitutions (consisting of location product, level and PPM) are added to the results list.
The results list is sorted by level number. The sequence of several substitutions within a level, however, is not jeopardized by the sort; that is, the original sequence of the location products in the basic quantity remains within the level. The lowest level has the highest priority and therefore appears first in the results list (that is, is checked first).
Product allocation is carried out for each row of the results list (all rows lead to the same product allocation procedure). Since later only one combination is chosen, all combinations of the list are alternatives to each other from the perspective of product allocation. This means that product allocation does not take into account the reservations from the previous combinations for a combination from the list.
After all rows have been checked, the first location product/PPM combination from the list that was completely confirmed is chosen. The confirmation logic of PP/DS ensures that this is a confirmation that lies within the tolerance range.
Rule evaluation using user exit (APOAT002)
The user exit is called after the check. If the user exit is active, substitutions that were returned from the rules can be selected. Furthermore, the confirmation (date and quantity) can be changed. Several substitutions are possible. In the hierarchical display of the explanation and simulation components you can only select one substitution.
For further information, in Customizing for the Advanced Planner and Optimizer select Global ATP ®
Enhancements ® Choose Substitutions.