What is the main purpose of an engineering notebook?

The main purpose of an engineering notebook is to document all work on a specific design project chronologically. This includes capturing ideas, designs, experiments, calculations, modifications, and overall project developments as they occur. By maintaining a detailed record in an engineering notebook, engineers can ensure that their thought processes and decisions are clearly documented, which can be crucial for future reference, verification, and compliance with intellectual property protection. This chronological documentation can serve as legal evidence of the innovation process and helps in keeping an accurate historical record of the project's evolution.

The focus on documenting all aspects of the project distinguishes this function from simply keeping track of critiques, sketching decorative ideas, or cataloging completed projects, all of which do not encompass the complete breadth and necessity of detailed chronological documentation that an engineering notebook is meant to achieve.