For the reduction of activity durations to function during overall network scheduling in SAP Project System, two fundamental prerequisites must be fulfilled at the time of execution. First, a pre-configured reduction strategy, which defines the rules for duration shortening, must be assigned within the network header's scheduling parameters (Option B). Second, the scheduling function itself must be explicitly instructed to perform the reduction by selecting the appropriate reduction type in the parameters for network scheduling (e.g., via transaction CJ29) (Option D). The absence of either of these settings will result in scheduling being performed without any reduction, matching the scenario described.

A. If the maximum reduction level is less than 100

This statement is not a valid reason for failure. Reduction levels are percentages and are almost always less than 100%. A failure would occur if all defined reduction levels were zero.

C. If the reduction strategy is set in each activity

This is incorrect because the reduction strategy is assigned at the network header level and applies to all relevant activities within that network; it is not an activity-level setting.

1. SAP S/4HANA Documentation - Project System (PS): The official documentation outlines the prerequisites for using lead time reduction. It explicitly states the need to (1) maintain a reduction strategy in customizing, (2) enter this strategy in the network header, and (3) specify in the scheduling parameters that reduction should be carried out. This directly supports options B and D as essential checks.

Reference: SAP Help Portal for SAP S/4HANA, "Project System (PS) -> Structures -> Network -> Scheduling -> Lead Time Scheduling -> Lead Time Scheduling with Reduction".

2. SAP Training Courseware (implied content): Curricula for SAP PS, such as PLM220 (Project Management: Structures), detail the end-to-end process. They distinguish between customizing settings (like defining the strategy's content), master data settings (assigning the strategy to the network header), and transactional settings (selecting the reduction type during the scheduling run). Options B and D represent the critical master data and transactional steps that a user must ensure are correct before expecting a result.