In SAP HCM payroll, what is the correct rule regarding master data and time data changes that affect the payroll past, payroll present, and payroll future during a payroll run?

Introduction / Context:
In SAP HCM payroll, the consistency of results depends heavily on using a stable snapshot of master data and time data for the payroll period that is being processed. If data is changed while the payroll run is in progress, there is a risk that some employees are calculated with old data and others with new data, which causes inconsistent and difficult to reconcile payroll results. For that reason, SAP and common project guidelines restrict changes to payroll relevant data during the execution of a payroll run for the same period.

Given Data / Assumptions:

• The payroll run is currently being executed for a specific payroll period.
• Payroll relevant master data includes information such as pay scale, wage types, bank details, and assignments that influence pay.
• Payroll relevant time data includes attendances, absences, overtime, and other time evaluation results that affect pay.
• The payroll past, present, and future describe time ranges that can affect the current payroll result, including retroactive periods.
• We are interested in the general rule for changing this data while payroll is running.

Concept / Approach:
The key concept is that payroll should be based on a consistent data set for the entire employee group included in the run. Therefore, many organisations freeze master and time data during the productive payroll run. Changes that affect the payroll past, present, or future are entered before or after the run and are then picked up either by the current run or by retroactive accounting in a later run. Technically, the system does not prevent any data change at database level, but process wise and often through locking mechanisms, changes are not allowed for the period that is being processed.

Step-by-Step Solution:
Step 1: Recognise that payroll calculates results for a defined payroll period and possibly retroactive periods. Step 2: Understand that if data is changed during the run, the first employees might be calculated with different data than later employees. Step 3: Consider how this inconsistency would make control lists, comparisons, and auditing very difficult. Step 4: Recall that standard payroll procedures instruct users not to change payroll relevant master or time data for the payroll past, present, or future while a productive run is active. Step 5: Conclude that the only safe and recommended rule is that such changes are not permitted while the payroll run is being executed.

Verification / Alternative check:
Imagine that you run payroll for the month of March. While the run is processing a large population of employees, a clerk changes the basic pay of one employee effective in March. Depending on the point at which the employee is processed, the change may be taken into account or ignored. The payslip, control reports, and posting to Finance would then be based on a mixture of old and new data, which is unacceptable in an auditable payroll environment. This scenario shows why organisations treat the payroll period as frozen during the run.

Why Other Options Are Wrong:
Option b is incorrect because the payroll run does not continuously reread changing data for already processed employees, and process rules explicitly avoid mid run changes. Option c is wrong because even changes in the payroll future can trigger retroactive accounting and must be controlled. Option d is misleading because using a separate test client and transports is a configuration and development approach, not a rule for operational data changes during payroll. Option e is incorrect because it would be very difficult to guarantee that changes never affect selected employees, and this does not reflect standard payroll controls.

Common Pitfalls:
A common mistake is to think only about the payroll present period and to ignore the impact of retroactive changes in the payroll past. Another pitfall is assuming that the system will automatically correct for any changes made during the run, which is not the case. For certification and practice, remember that payroll relevant master and time data that affects payroll past, present, or future is considered frozen while a productive payroll run is being executed.

Final Answer:
During an SAP HCM payroll run, changes to payroll relevant master data and time data that affect the payroll past, payroll present, or payroll future are not permitted while the run is in progress.