In SAP Project System (PS), network scheduling determines the activity dates using the Critical Path Method (CPM). This process involves two passes. First, forward scheduling is executed, starting from the project's basic start date, to calculate the earliest possible start and finish dates for each activity. Subsequently, backward scheduling is performed, starting from the project's basic finish date (or the earliest finish date determined by the forward pass), to calculate the latest permissible start and finish dates for each activity without delaying the project's overall completion. The difference between these earliest and latest dates determines the float.

A. This option incorrectly reverses the scheduling methods. Backward scheduling calculates the latest dates, not the earliest, and forward scheduling calculates the earliest dates, not the latest.

C. Forward scheduling alone only calculates the earliest dates. A separate backward pass (backward scheduling) is required to determine the latest dates and available floats.

D. This is incorrect on two counts. Earliest dates are determined by forward scheduling, not backward. Latest dates are calculated and are not simply a copy of the earliest dates.

1. SAP Help Portal, SAP S/4HANA: Scheduling Process. This official documentation states, "The system first carries out forward scheduling to calculate the earliest dates. It then carries out backward scheduling to calculate the latest dates. The difference between the earliest and latest dates is the float." (SAP S/4HANA, Enterprise Portfolio and Project Management > Project System (PS) > Dates > Scheduling > Scheduling Process).

2. SAP Help Portal, SAP S/4HANA: Scheduling. This document outlines the purpose of network scheduling: "Network scheduling calculates the earliest and latest start and finish dates for activities..." This confirms that both sets of dates are calculated as distinct steps. (SAP S/4HANA, Enterprise Portfolio and Project Management > Project System (PS) > Dates > Scheduling).

3. Meredith, J. R., Shafer, S. M., Mantel Jr, S. J., & Sutton, M. M. (2017). Project Management: A Strategic Managerial Approach. In Chapter 8, "Scheduling the Project," the text describes the Critical Path Method (CPM), which is the foundation for SAP's scheduling logic. It details the "forward pass" to find the earliest start and finish times and the "backward pass" to find the latest start and finish times. (Specifically, see sections on "The Forward Pass" and "The Backward Pass").