This document outlines the National Pharmaceutical Regulatory Agency's process for handling product complaints in Malaysia. It discusses three key activities: 1) post-market quality surveillance through market sampling and laboratory analysis, 2) investigating complaints related to quality, regulation, or safety/efficacy, and 3) monitoring product safety profiles. The document defines critical, major, and minor quality defects and provides examples of each. It emphasizes that product complaints are an important tool for surveillance and companies are required to investigate the root causes of critical defects and propose corrective actions.