In SAP preventive maintenance work order basic start date is after final due date

[kishorkokitkar]

We are facing issue with preventive maintenance work order Basic Start Date and Final due date.

In our work order Basis start date is 02/02/2026 and final due date is 01/31/2026.

We are using 7 day factory calendar in both plant and work center assignment. 

Even though basis start date is getting scheduled as per 5 working days. (31st Jan is Saturdays).

Please help me to understand , why system is not scheduling as per 7 working days. We want to schedule as per 7 working days.

[Lakshmipathi]

What you’re seeing is actually standard SAP scheduling logic in Plant Maintenance (PM) — the system is not “ignoring” your 7‑day factory calendar, but rather applying the rules of basic dates vs. scheduling dates.

• Basic Dates (start/finish) are entered manually or derived from the maintenance plan.
• Final Due Date comes from the maintenance plan cycle (e.g., monthly, yearly).
• When you schedule, SAP checks the factory calendar assigned to the work center/plant.
• Even if you’ve defined a 7‑day calendar, the system still respects the “normal scheduling logic”:
  • It calculates the start date backwards from the due date using the work center scheduling parameters (e.g., 5 working days lead time).
  • If the due date falls on a non‑working day (Saturday in your case), SAP shifts the date to the nearest valid working day.

Why it looks like 5 Days instead of 7 is because, the work center capacity category and scheduling parameters may still be set to a 5‑day week, even though the factory calendar is 7 days. In PM, both the factory calendar and the work center capacity settings must align. If the work center is defined with Monday–Friday as working days, the system will schedule accordingly, regardless of the factory calendar. That’s why your order is showing 31 Jan (Saturday) as “non‑working” and pushing the basic start date earlier.

To fix this, perform the following

• Check Work Center Capacity Settings (CR02/CR03) and verify the capacity category and operating time. Ensure the work center is set to use the 7‑day calendar.
• Check Maintenance Plan Scheduling Parameters and confirm the cycle and offset are aligned with 7‑day scheduling. Reschedule the Order after correcting the work center calendar assignment.