Quality agreement and warranty: responsibilities and remedies

What a quality agreement is, and what it is not

A quality agreement is the document that turns a drawing and a purchase order into a working quality process. It defines the specification, the acceptance method, the inspection responsibilities, the records and the response when something goes wrong.

It is not a replacement for the drawing, and it is not a warranty. The drawing defines the part. The warranty defines the remedy. The quality agreement sits between them and describes how both sides prove that the part meets the drawing before and after delivery.

That distinction matters because buyers often try to put every quality expectation into the purchase order. A short purchase order cannot carry a sampling plan, a change control process and an inspection record. A separate agreement can, and it can be updated without reissuing every order.

Start from the specification

The agreement should reference the drawing revision, the material specification and any standard the part must meet. It should also list the critical to quality characteristics, the ones that decide fit, function or safety, so that inspection effort goes where it matters.

For each critical characteristic, state the method, the gauge and the frequency. If the part is measured with a calliper, say so. If it needs a CMM or a functional test, say so. The method decides the uncertainty, and the uncertainty decides whether a reading near the limit is a pass or a fail.

Include the material and finish requirements. A certificate of conformity is not the same as a certificate of analysis, and neither replaces an incoming check. State which certificate is required, what it must contain and whether a mill certificate is needed for traceability.

If the drawing has a general tolerance, name the standard and the class. If the part has a GD&T callout, state the datum reference frame and the inspection method. A tolerance that cannot be measured in a repeatable way is a source of argument, not a specification.

Acceptance and inspection responsibilities

Split the inspection into three stages: incoming material and component checks, in process checks and final inspection. For each stage, state who performs it, what is recorded and what happens when a result is out of specification.

The supplier usually owns the in process and final inspection and provides the record with the shipment. The buyer usually owns the incoming inspection and any functional test that needs the assembly. Where the buyer relies on the supplier's record, the agreement should say so, and should define the audit right that supports that reliance.

Sampling needs a standard. Name the plan, the inspection level and the acceptance number, or attach a control plan. A zero acceptance plan is stricter but needs a process that can hold it. A plan that accepts a small number of defects needs a clear definition of what counts as a defect.

Define the first article. A first article inspection should cover every dimension on the drawing, the material certificate and any functional result. It should be repeated after a tool change, a process change, a relocation or a long gap in production.

Non-conformance, deviation and corrective action

A non-conformance should have a defined route. The supplier contains the suspect stock, identifies the batch, sorts or quarantines it and tells the buyer. The buyer decides whether to reject, return, rework or accept with a concession.

A deviation is a planned exception. It should be requested in writing, with the quantity, the affected characteristics, the reason and the proposed disposition. A deviation that is agreed verbally is not a deviation, it is a future dispute.

Corrective action should go beyond the immediate batch. The supplier should identify the cause, the containment, the corrective action and the verification. The buyer should review the response and close it only when the evidence supports closure.

Track the cost of poor quality. Sorting, rework, return freight, expedited replacement and line stop time are all real costs. The agreement can allocate them, and the record can support a claim. Without the record, the buyer is negotiating from memory.

What the warranty should cover

A warranty is a promise about the condition of the goods. It should state what is covered, how long it lasts, when it starts and what the buyer must do to claim. A warranty that says only that the goods are free from defects is too vague to administer.

Cover the part against defects in material, workmanship and conformance to the drawing. Decide whether the warranty covers the cost of removal, re installation, transport and the consequential loss of a line stop, or only the replacement value of the part. The difference can be large.

Set the duration by the failure mode, not by habit. A part that wears in service needs a different period from a part that fails on assembly. If the part is installed in a larger assembly, the warranty may need to run from the date of installation or the date of the end customer's purchase, subject to a long stop date.

Exclude what the supplier cannot control: misuse, unauthorised modification, incorrect storage and normal wear. Make the exclusions specific, because a broad exclusion can undermine the whole clause.

Remedies that can actually be used

The remedy sequence should be simple. Repair, replace, credit, rework at the buyer's site, then a price adjustment or termination. Each step needs a time limit and a responsible party.

Replacement is the usual remedy for a discrete part. Credit is simpler for a consumable or a low value item. Rework at the buyer's site can be faster than a return shipment, but it needs an agreed method and a cost cap.

For a line stop, the buyer may need to source an emergency batch from another supplier. The agreement should allow that, and should state who pays the premium. A clause that requires the buyer to wait for the original supplier to replace the batch is not workable in a shutdown.

Whatever the remedy, define how it is triggered. A written notice, an inspection record and a return authorisation are enough for most cases. A remedy that depends on a court decision will not help the production manager on a Friday afternoon.

Making the agreement work

Review the agreement at the start of every programme and after any significant change. A new drawing, a new tool, a new material or a new site can invalidate the assumptions behind the inspection plan.

Keep the records together: the agreement, the drawing revision, the first article, the control plan, the material certificates and the non-conformance history. A quality agreement is only useful if the evidence behind it can be found.

Use the data. If the same defect recurs, the agreement may be asking for the wrong inspection, or the process may need a change. A quarterly review with the supplier is more effective than a clause that is only read after a failure.

• Review the agreement at every drawing or process change.
• Keep the first article and the control plan with the current revision.
• Track non-conformances by defect type, not only by batch.
• Close corrective actions only when the evidence supports closure.