What Is an MRB (Material Review Board) and How Does the Disposition Process Work?

In manufacturing, nonconforming material is inevitable. But how do you decide whether to scrap a costly part, rework it, or use it as-is? That decision is not made by a single inspector—it is made by a Material Review Board (MRB). This article explains what an MRB is, how its disposition process works, and how you can apply it in your organization.

What It Is

A Material Review Board (MRB) is a formally designated group of cross-functional experts who review nonconforming products or materials and determine their final disposition. The MRB concept is widely used in aerospace, defense, and other regulated industries where product integrity and traceability are critical.

The board typically includes representatives from engineering, quality, manufacturing, and sometimes the customer or regulatory authority. Its purpose is not to assign blame but to make a documented, risk-based decision on what to do with material that does not meet specifications.

How It Works / Steps

The MRB process follows a structured disposition workflow. The four primary dispositions are:

1. Use-As-Is – The material is acceptable for its intended use despite the nonconformance, often with customer approval.
2. Rework – The material is modified to bring it back into full conformance with the original specification.
3. Repair – The material is modified to make it serviceable, but it will not fully meet the original specification.
4. Scrap – The material is unusable and must be discarded or recycled.

The general steps are:

1. Identification – Tag and segregate the nonconforming material.
2. Documentation – Record the discrepancy (e.g., dimension out-of-tolerance, wrong material grade).
3. Board Review – The MRB meets to review the discrepancy report, engineering drawings, and any test data.
4. Disposition Decision – The board selects one of the four dispositions and documents the rationale.
5. Implementation – Execute the disposition (e.g., send to rework, obtain customer waiver for use-as-is).
6. Follow-up – Initiate corrective action to prevent recurrence, if warranted.

A Worked Illustrative Example

Example data (illustrative only):
A machined aluminum bracket for an aircraft seat has a hole diameter of 8.15 mm, while the specification requires 8.00 ± 0.10 mm. The part is nonconforming because the hole is 0.05 mm oversized.

The MRB reviews the case:

• Engineering analysis: The hole is for a locating pin. The pin has a tolerance of 7.95 ± 0.05 mm. The maximum interference condition is acceptable, and the oversized hole does not affect structural strength.
• Customer requirement: The customer contract allows deviations up to 0.10 mm for this feature.
• Decision: The board issues a Use-As-Is disposition with a documented waiver.

The part is released, the disposition is recorded in the quality system, and a corrective action request is opened to investigate why the drilling process drifted.

Common Pitfalls

• Making the MRB a one-person show. Without genuine cross-functional input, decisions may miss engineering or customer implications.
• Using "use-as-is" too freely. This disposition should require documented evidence and, where needed, customer approval—not convenience.
• Skipping corrective action. Dispositioning the material is not the end; you must address the root cause to reduce future nonconformances.
• Poor documentation. An undocumented MRB decision is worthless in an audit or liability context.

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The MRB process turns a potentially chaotic nonconformance event into a controlled, traceable decision. To streamline your board reviews and disposition records, try the free MRB material review tool at https://www.6sq.com/tools/mrb/.