This document focuses only on equipment design. Items such as human error@ behavior-based safety@ and operating procedure issues are not in the scope. The Tool covers equipment that is common to both upstream producing and downstream manufacturing operations. Equipment associated with specific activities@ such as drilling rigs is not specifically addressed. The human factors principles described in this document are intended for new equipment designs; however@ many ideas provided in this Tool may be used to improve the operation of existing plants@ where feasible.