This document discusses change control in the pharmaceutical industry. It defines change and change control, and outlines the tasks, principles, regulatory requirements, and elements of a change control system. The document describes the steps in a typical change control process, including classifying, assessing, planning, implementing, evaluating, and closing changes. It provides examples of major and minor changes and discusses the documentation and challenges of maintaining an effective change control system. Maintaining proper communication, turnaround times, documentation, and training are important for managing changes in a controlled manner.