The provided document, “OpEx – GMP Modules All in One.pdf” by Vishnu Rayapeddi, serves as a comprehensive training manual on Good Manufacturing Practices (GMP). It systematically covers the fundamentals of GMP, defining its purpose as ensuring products are consistently manufactured to a quality appropriate for their intended use, ultimately leading to customer satisfaction. The manual meticulously details how GMP applies to people (training, health, hygiene, attitude), buildings (space, light, planned flow, environmental controls, maintenance), and systems (identification, double-checking, documentation). Furthermore, it elaborates on critical aspects like labelling, weighing, personal hygiene, and cleaning processes, emphasising the prevention of mix-ups, contamination, and product performance issues. Finally, the text explains how compliance is measured through internal and external audits, process control, customer complaints, and adherence to specifications and yield calculations, underlining the legal, corporate, and moral imperatives for following GMP.