What are the primary functions of "as-built" drawings?

The primary functions of "as-built" drawings are to document the final configuration of a project as it was actually constructed, reflecting any changes made from the original design. This makes them crucial for understanding how the system was built, which directly aids in future troubleshooting and repairs. By having a detailed representation of the installed system, technicians can more easily identify issues, locate components, and understand how the system operates in its real-world setup.

While the other options relate to potential benefits of as-built drawings, they do not encompass the broadest purpose. "As-built" drawings do show the final system configuration and document changes made during installation, as well as provide a historical record. However, the standout function that is essential for maintaining and managing the system long-term is their role in assisting with troubleshooting and repairs, as having accurate documentation is vital for quick reference and efficient problem-solving.