Age‐based opportunity maintenance

Suggests new ways to construct and update preventive schedules for a complex system by making better use of system failure down time to do preventive work without further productive loss. The methodology is based on age renewal but necessarily approximate. However, it includes the recursive effects of maintenance on system MTBF, and of opportunities insufficient to prevent system deterioration. Opportunity maintenance theoretically self‐adjusts; if insufficient opportunities arise, average lateness increases, and failures increase until a balance is achieved, but minimum conditions exist for a given age renewal schedule, and the natural balance may not be economically optimal.