You’re running APS with forward scheduling and the Material availability check functionality active for your planning scenario. The checkbox Material OK remains deactivated when a bill of material item is an assembly set as Breakdown Storage related in the master data but has been set as Breakdown only shortage in BOM where it is being used.
Here’s an example Item Structure:
In this case, the sub-assembly is a storage related item but in this BOM for item PA063.02 it has been set as “Breakdown – Only Shortage”.
The Breakdown parameter set on the BOM is not considered by the APS calculation. APS will look at the setting you have on the item master data. Therefore, unless you have a separate work order for the assembly (in this case for item SA054.02) the “Material ok” check-box when planning item PA063.02 will not be set.
Example 1, Planning Item PA063.02 with no separate sub assembly work order for item SA054.02:
Forward scheduling scenario, with material check before scheduling. No flag is set.
Example 2, Planning Item PA063.02 with an existing separate sub assembly work order for item SA054.02, both orders planned together on the same APS scenario:
In this case, both orders have been set to be started on a given date, forward scheduling with material check. The sub-assembly order is planned BEFORE the finished product order (since it is the first line on the screen) and then the finished product will receive the “Material ok” check box since the sub-assembly will be in stock before the order is started.
You can also check the online help here: