Manual of Permitted Operations (MOPO)

A manual of permitted operations (MOPO), also referred to as a matrix of permitted operations, is a visually coded manual used to define whether a work activity can be conducted safely within a given condition (e.g. within darkness). A particularly common area of concern that is addressed by MOPOs is whether two activities can be conducted safely at the same (referred to as simultaneous operations, or SIMOPs).

MOPOs are used primarily within the context of the oil and gas industry, but they may also be employed within the broader process industries. They are generally presented as a matrix or group of matrices and utilize a traffic-light system (red—stop; yellow—caution; green—go) to identify whether an activity or set of activities is safe to proceed with under a given set of conditions.

A fully developed MOPO can also provide contingency guidance in the case that an element of a normal operational procedure fails. That is, if an operational element of the workplace fails—such as a PA or other communication system—a MOPO may be consulted to review what, if any, work operations may still be performed safely.