The Material Review Board (MRB) is a cross-functional team of experts that meets regularly to review non-conforming parts and materials. The MRB documents non-conformities in Non-Conformity Reports (NCR) and decides on a disposition, such as using the part as-is, reworking it, or scrapping it. Their goal is to ensure quality while minimizing costs and downtime. Key responsibilities include analyzing deviations's impacts, determining necessary actions, and approving or cancelling dispositions.