Manufacturing companies often wish to copy and improve upon their competitors' products, but cannot directly do so for legal reasons.
Clean room design is an attempt to
reverse-engineer a design and then recreate it without infringing any of the
patents or
copyrights associated with the original design. The term implies that the design team works in an environment that is 'clean', or demonstrably uncontaminated by any knowledge of the proprietary techniques used by the competitor.
The term 'clean room' used on its own has a different meaning in the field of integrated circuit manufacture.