Engineers reviewed more than 15,000 work orders in the quest to identify the extent of preventable maintenance for major corporations in North America.
The concept of preventable maintenance (“Focusing on Preventable Maintenance,” MT 10/95, pg 23) has matured into one of the most powerful factors used by HSB Reliability Technologies’ (HSBRT) engineers to drive the reliability improvement process and lead clients to manufacturing excellence.
As with most good ideas, the process has been enhanced with experience. In addition to improvements in the investigative process, significant progress has been made in the solutions arena. It is also clear that there is still room for improvement of the investigative process.
HSBRT engineers now review two more aspects of the extent of preventable maintenance. The accompanying pie charts, from a study of more than 1000 work orders in a large plant, depict preventable maintenance in three ways.
It is first expressed as a percentage of the total number of work orders reviewed. The next chart shows preventable maintenance as a percentage of total maintenance hours. The third chart depicts preventable maintenance costs as a percentage of total maintenance costs.
As a percentage of total work orders
The graph confirms the original assumption that reasonably preventable maintenance approximates half of the work accomplished in most organizations. In this case it was exactly 47 percent. In this plant, an overly simplistic conclusion would be that about $18 million of labor and material was wasted.
As a percentage of total hours worked
HSBRT engineers decided that it would be beneficial to carry the analysis one more step. When expressed in hours worked, preventable maintenance appears to be a larger piece of the pie, in this case, 63 percent. A possible conclusion is that the preventable work orders were more complex, or at least more time consuming.
As a percentage of expenditures
Using the findings of the previous exercise, we examined the preventable work orders on the basis of total maintenance expenditures to determine the nature of the materials component. The percentage climbed to 69 percent. It would be prudent to conclude that preventable maintenance is more costly in labor and materials. Theoretically, $26 million was wasted in the study plant instead of $18 million.
HSBRT engineers are now working to capture the impact of preventable maintenance in dollars of lost opportunity, or profitability of a particular plant. This measure has proved to be somewhat more difficult to define. We will keep you posted on our progress.
We are also working on specific solutions in systems, procedures, processes, and practices to minimize the impact of preventable maintenance. We have found reliability-centered maintenance/solutions and root cause failure analysis to be effective tools in this venture.
Identifying and controlling preventable maintenance are critical activities for managers who are serious about improving reliability and reducing maintenance costs. That may well be the most important area of focus because of the leverage on cost and throughput. MT
Raymond J. Oliverson is executive vice president and general manager of HSB Reliability Technologies, Consulting Div., 800 Rockmead Dr., Kingwood, TX 77339; (281) 358-1477.
HSBRT engineers Greg Como and Harold Weimer contributed to the article.