NRI’s white paper on operational readiness presents twelve, linked principles. The first, Nertney’s principle, is to plan and manage any operational system, or process, as a whole made of four parts. The first three parts are people, equipment and work methods. These are the basic elements of work. The fourth part is the set of conducive conditions which allow the other three parts to perform well. Accidents and quality problems are signs that one or more of the four parts does not match the others. The system might be in operation, but it’s not ready in the Nertney sense that all the parts must be ready and in sync. Maybe the operation was set up that way? Perhaps something’s changed? Sometimes, going too far with lean practices such as ‘management by stress’ can make a system unready. Often, the people in the operation can compensate for mismatches, but within limits and not forever. Usually there’s a cost in reliability, safety or welfare. The Nertney principle applies to keeping an operation ready, but also to designing and building it. Designers have to make assumptions about how people, equipment and methods will perform. They also need to specify the critical conditions that management must sustain. These assumptions will have various degrees of accuracy. During the lifecycle, active monitoring is needed to verify that the work elements and conditions are (still) behaving as the designers expected. And this monitoring should be reflective; seeking to better balance the operation so it tends towards readiness.