The control key is the primary configuration element that determines whether capacity requirements are generated for a network activity. Within the customizing settings for a control key, there is a specific indicator, "Capacity requirements," which must be activated. If this indicator is not set in the control key assigned to an activity, the system will not generate any capacity requirements for that activity, regardless of the work specified or the work center assigned. While scheduling determines the timing and the work center provides the formulas for calculation, the control key acts as the essential trigger for the entire process.

A. Independent of scheduling and according to the capacity planner group.

Capacity requirements are fundamentally dependent on scheduling for their dates and duration. The capacity planner group is used for organizing and evaluating requirements, not for determining them.

B. Using scheduling and the capacity category.

While scheduling is necessary, the capacity category (e.g., labor, machine) simply defines the type of capacity in the work center. It does not trigger the calculation itself; the control key does.

D. Using scheduling and distribution key.

The distribution key determines how the total work (and thus the capacity load) is distributed over the activity's duration. It influences the shape of the requirement over time, not its initial creation.

1. SAP S/4HANA Documentation - Help Portal:

Document: Project System (PS) -> Structures -> Network -> Network Activity -> Control Key

Reference: The documentation explicitly lists the functions governed by the control key. One of the key indicators is "Cap. reqmts" (Capacity requirements). It states, "This indicator specifies that capacity requirements records are generated for the activity." This confirms the control key's role as the primary determinant.

2. SAP S/4HANA Documentation - Help Portal:

Document: Project System (PS) -> Dates -> Scheduling -> Capacity Planning in the Project System -> Determining Capacity Requirements

Reference: This section details the prerequisites for determining capacity requirements. It lists: "The control key for the activity must specify that capacity requirements are to be generated," alongside the need for a work center with formulas and the entry of work in the activity. This highlights the control key's mandatory role.

3. SAP Training Courseware (Implicit Content Structure):

Course: TS410 (Integrated Business Processes in SAP S/4HANA) & CTS412 (SAP S/4HANA Project Systems)

Reference: In the unit covering Project Structures and Networks, the control key is introduced as a central controlling instrument for activities. The configuration of the control key is shown to manage costing, scheduling, confirmations, and capacity planning, reinforcing its function as the master switch for these processes.