ERP & MRP Planning worked example

Work Order Aging with total open work-order age of 3,200 order-days: a worked example

This scenario runs the work order aging calculation on the strong side: total open work-order age of 3,200 order-days, with every other input held at its documented default. a production planner needs to summarize how old open work orders are

The inputs for this scenario

  • Total open work-order age: 3,200 order-days (raised for this scenario; the documented default is 1,260)
  • Open work-order count: 84 orders (unchanged)
  • Calendar adjustment factor: 1 x (unchanged)

Working through the calculation

  • Applying the documented formula (Average work-order age = total open work-order age ÷ open work-order count × calendar adjustment factor) to the inputs above produces each figure below.
  • At this operating point the engine returns 38.1 days for average work-order age, the number this scenario is built around.
  • At this operating point the engine returns 38.1 days for average age before calendar adjustment.
  • At this operating point the engine returns 1 x for calendar adjustment factor.
  • At this operating point the engine returns 84 orders for open work-order count.

How this compares with the baseline

  • Against the tool's baseline example, where total open work-order age sits at 1,260 order-days and the headline result is 15 days, this scenario comes in 154% above the baseline at 38.1 days.
  • Use it weekly or daily to monitor WIP health and flag aging orders before they become past-due. Treat this as a target state: the delta against the baseline quantifies what the improvement is worth before you commit to chasing it.

Results at a glance

  • Average work-order age: 38.1 days (headline result)
  • Average age before calendar adjustment: 38.1 days
  • Calendar adjustment factor: 1 x
  • Open work-order count: 84 orders

Run it with your numbers

  • Every input above is editable in the live Work Order Aging calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.