ERP & MRP Planning calculator
Work Order Aging Calculator
Work Order Aging helps planners and supervisors spot stale WIP, stuck jobs, and orders that have exceeded normal flow time.
What this calculator does
- Estimate average open work-order age from total aged order-days and open work-order count.
- a production planner needs to summarize how old open work orders are
- It estimates the average age of open production orders.
Formula used
- Average work-order age = total open work-order age ÷ open work-order count × calendar adjustment factor
Inputs explained
- Total open work-order age: Sum the age in days for all open work orders in scope.
- Open work-order count: Count released, started, or open work orders in the same scope.
- Calendar adjustment factor: Use 1.0 normally, or adjust for working-day versus calendar-day reporting.
How to use the result
- Use it during ERP cleanup, MRP review, production scheduling, S&OP prep, purchasing decisions, shortage meetings, capacity planning, or daily shop-floor execution reviews.
- This is a planning estimate. Confirm final commitments against current ERP/MRP records, released BOMs and routings, inventory accuracy, supplier commitments, open work orders, quality holds, and shop-floor constraints.
Common questions
- What is the Work Order Aging calculator for? It estimates the average age of open production orders.
- What information do I need before using it? You need total order-days, open work-order count, and any calendar adjustment.
- How should I use the result? Use it to find stale WIP, prioritize reviews, and clean up old ERP work orders.
- When is the result only an estimate? It is only an estimate when demand, inventory, lead time, routing hours, setup time, yield, supplier dates, or work-center capacity comes from forecast assumptions or stale ERP data instead of current orders and recent execution history.
Last reviewed 2026-05-12.