Clean Room Design

CORE DEFINITION

Clean room design is a method for replicating a competitor's functionality without infringing copyright, using two strictly separated teams. Team A studies the original code and produces a functional specification that contains no protected expression; Team B, which never sees the original code, implements a new version from that specification alone. The separation filters protected expression out of the flow and leaves only the unprotected ideas behind, so the imitation is lawful. A second meaning covers controlled-environment facilities for semiconductors and pharmaceuticals, and Harlan Mills's software method that replaces testing with formal verification.