Final answer:
Designers/engineers record their daily project work in a logbook to archive their work and legally prove the origin of an idea.
Step-by-step explanation:
Designers/engineers record their daily project work in a(n) logbook to archive their work and to legally prove the origin of an idea. A logbook serves as a documentation tool for engineers, helping them remember how they solved problems and why they made certain design choices. It can also be used as evidence for gaining patents, defending designs in case of failures, and proving hours worked.