Revision effectivity is the defined point at which a specific revision of a document, part, process, or instruction becomes applicable. In manufacturing, it states which revision applies to which orders, lots, serial numbers, dates, operations, or production steps.
Revision effectivity is commonly used in document control, MES, ERP, PLM, quality systems, and shop floor execution workflows. It helps distinguish work that remains under an older revision from work that must use a newer revision, especially when work in process already exists at the time of a change.
Effectivity may be based on a calendar date, production order, lot, serial number range, configuration, routing step, or formal change release. For example, a work instruction revision may apply only to new orders released after a certain date, while active WIP may continue under the prior revision or transition at a defined operation.
Revision effectivity should not be confused with the revision level itself. The revision level identifies the version, such as Rev B or Rev C. Revision effectivity defines where and when that version is valid for use.