What Is Rework?
Also known as: repair, reprocessing
Definition
Rework is action taken on nonconforming product to bring it into full conformance with the original specification. It differs from repair, which makes product acceptable for use without meeting the original requirement.
Rework Explained
The distinction between rework and repair is precise in regulated industries and consequential. Rework restores full conformance to the drawing or specification, so the finished item is indistinguishable in requirement terms from one built right the first time. Repair produces an item that is usable but does not meet the original specification, which requires a documented deviation or material review board disposition and, on defense and aerospace programs, frequently customer concurrence before the product can ship.
Rework cost is systematically underestimated because most of it never lands in a job. The visible cost is the direct labor hour. The invisible costs are re-inspection, re-test, additional material handling, paperwork and disposition time, planner and quality engineer attention, schedule disruption from the unit leaving and re-entering flow, and the capacity consumed on machines that could have been building new orders. A commonly used rule of thumb is that fully loaded rework cost runs three to five times the reported labor hours.
Capturing rework in the ERP requires a deliberate structure. Options include a separate rework job that pulls the nonconforming item and charges its own labor, a dedicated rework operation on the original routing, or a nonconformance record in a quality module that drives its own transactions. What does not work is letting operators charge rework time to the original operation, which inflates the apparent standard, corrupts the routing, and makes rework invisible in every report thereafter.
In AS9100 and defense contexts, rework triggers documentation obligations well beyond the shop floor. A nonconformance record, root cause, disposition, and traceability linkage are typically required, and units that were reworked may need to be identified in the delivered configuration record. Plants that treat rework as an informal fix at the bench frequently discover the gap during a customer audit, when reworked serial numbers cannot be reconciled against nonconformance documentation.
Why It Matters
- Fully loaded rework cost commonly runs three to five times the reported labor hours once inspection, handling, and disruption are counted.
- Rework consumes capacity on the same equipment needed for new orders, so heavy rework directly extends promised lead times.
- Charging rework to the original operation corrupts routing standards, job costing, and every capacity plan built from them.
- Regulated programs require nonconformance records and disposition for reworked units, so informal bench fixes create audit exposure.
In Practice
A weld shop reports 140 rework hours per month at a 45 dollar loaded rate, about 6,300 dollars, and treats it as acceptable. Tracking the full path shows each rework event also consumes 20 minutes of re-inspection, 15 minutes of quality engineer disposition, a second heat-treat cycle on a third of units, and an average of two days of schedule slip. Loaded cost lands near 27,000 dollars per month, and more importantly, the weld booths lost capacity equal to roughly 9 percent of their available hours.
Frequently Asked Questions
What is the difference between rework and repair?
Rework brings nonconforming product back into full compliance with the original specification, so no deviation is needed. Repair makes the product acceptable for its intended use without meeting the original specification, which requires a documented deviation or material review board disposition and often customer approval in aerospace, defense, and medical device manufacturing.
How should rework be recorded in the ERP?
On a separate rework job or a distinct rework operation, never charged to the original operation. Separating it keeps routing standards clean, makes rework visible in cost and capacity reporting, and preserves the link to the nonconformance record. If rework time hides inside standard operations, the routing slowly inflates and the true quality cost disappears from view.
Related Terms
Scrap Rate
Scrap rate is the percentage of production output discarded as unusable because it cannot be economically reworked to specification, calculated as scrapped units divided by total units produced over a defined period.
First Pass Yield
First pass yield is the percentage of units that complete a process correctly the first time, without rework, repair, or retest. Units that eventually pass after rework are excluded, so the metric captures hidden factory loss.
Traceability
Traceability is the ability to follow the history, location, and application of a part or material through the supply chain and production process, both backward to its sources and forward to every product and customer it reached.
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