Engineering may approve a drawing revision while the plant still has old stock, open work orders and partly built units. “Use Rev D from now on” does not tell a planner what to do with any of them.
Effectivity is the answer to a narrower question: which build gets which version? It may be set by date, work order, lot or serial number. The right boundary depends on the product and the change.
Start with the affected build, not the document list
For each open order, check the approved drawing, bill of material, routing and work instruction. Then check the material already bought, kitted or consumed. A document can be current in engineering and still be wrong for a unit already in assembly.
Build one impact list that distinguishes:
| State | Decision needed |
|---|---|
| Not started | Can this order start on the new revision? |
| Material kitted | Does the kit need to change? |
| Work in process | Can the unit continue, or does it need rework or disposition? |
| Completed or shipped | Is a field or customer action required? |
Do not infer a quality disposition from the new drawing alone. Engineering can describe the technical change; quality and the authorized product owner decide how affected units are treated under the site’s rules.
Name the boundary and the exception
Suppose WO-2051 has not started, but WO-2048 has twelve assembled units. The team may start WO-2051 on Rev D after changing its kit. The twelve units on WO-2048 need a separate decision. Record both outcomes and the approval behind them.
An effectivity record should identify the change, the first applicable build, the last build on the old version, open exceptions, and the owner of each decision. A date alone is often too weak when jobs span several shifts or plants.
Check the first build on the new revision
Confirm that the next job shows the approved revision at the station, the material matches it, and the first build records the intended version. If any of those checks fail, pause the job and resolve the mismatch before it becomes an as-built traceability problem.
NIST’s digital-thread work treats the handoff among engineering, manufacturing and quality as a core information problem. Effectivity is where that handoff becomes a decision about real units.
See how Bourne approaches engineering change control.
Buğra Gündüz
Buğra Gündüz is the co-founder and CEO of Bourne and co-founder of HockeyStack. He built HockeyStack into an eight-figure AI business. At Bourne, he works with entrepreneurs and established companies to create AI products and services.