Overview

Preventive and corrective maintenance models are built from basic assumptions generalizations not always born out by facts. The traditional PM model assumes:

• PM is always less costly than failure

• equipment can not be run effectively with "failure-based" maintenance

• we understand and can recognize "failure"

• the consequences of missing PM is failure

Can simple failures progress to functional failures? Can functional failures impact equipment and systems? This is what we seek to understand and, ultimately, remedy. These are the lessons.

Even the best, most optimized, experience-based designs are no more than relatively insensitive to failures. The natural progression for equipment over its production life is to increase failure resistance by design as field experience increases; ultimately, however, how people perform is what actually matters. Some organizations "gun deck" maintenance paperwork (like PMs); workers don't blindly buy into processes. Failure process ignorance, or a lack of participation in PM identification, selection, and development limits worker process commitment.

Root cause analysis can be a factor. Until actual strategy and costs are developed, it's not often clear which maintenance approaches are likely to yield the best overall task, or which combination of tasks best address potential failures at the lowest cost. Until the plan is implemented and statistically meaningful costs are collected, value cannot be established. Backing off existing, low value PM is just as tough as establishing high value programs.

Compare CDM...