Remove Downtime Causes

Klaus M. Blache | June 1, 2023

Downtime, in simplest terms, is when assets are not available for use as needed.

This can be for unscheduled or planned downtime. When I assess factories or take plant tours and discuss challenges and opportunities, there are many reasons given for causes of asset downtime. Here are the 30 most common:

• Lack of preventive maintenance
• Too much early intervention/excessive maintenance
Human error during maintenance
Human error by operators
Too much reactive maintenance
Improper storage practices
Poor crib management
Lack of a reliability/proactive maintenance culture
Mechanical-component wear
Stopped to resolve quality issues
Lack of effective planning and scheduling
Software/IT system issues
Power outage from internal infrastructure issues
Power outage, lightning strike, and other weather or external reasons
Outages (planned or unplanned) because of asset deterioration
Never designed/installed correctly and has never produced at expectation
Aging assets
Inability to obtain replacement parts when needed
Operating with less-experienced people due to high employee turnover
Insufficient use of predictive technologies
Use predictive technologies, but don’t do sufficient root cause analysis
Maintenance that cannot be performed while assets are operating
Investigations for safety/accident follow-up or continuous improvement
Management decisions to operate longer/faster and postpone maintenance
Limited number of employees who can maintain specific equipment
Lack of clear and sufficiently detailed maintenance tasking instructions
Performing maintenance, but not doing it according to instructions/best practices
Poor cleaning practices
Insufficient time to perform maintenance
Lack of “design for reliability and maintainability”

The 30 reasons for downtime can be placed into three general groups.

If all you do is look at the initial downtime symptoms observed, the reasons fall into the categories as shown in Figure 1. Many of the items could be people or process, so those items were split in the tally.

The 30 downtime reasons can be assigned to individuals/departments to better assess responsibility.

I also grouped the 30 downtime reasons into four categories based on who controls them (Figure 2). The Engineering (Equipment & Other) category includes items such as outages, wear on mechanical components, aging assets, and safety investigations. Improved focus on the exact breakdown issues would, of course, depend on maturity of the current reliability and maintenance processes and the workforce readiness for change. More than 70% of companies still point to culture as the biggest roadblock to instilling a proactive mindset. Similarly, where plant-floor practices and culture enable an operator to get more involved in R&M, the benefits significantly decrease downtime.

Actionable items should be prioritized by cost and timeliness of implementation versus benefits. Then identify how improvement will be measured. Finally, discuss what leadership supporting behavior will be needed to instill the better practice and leading key performance indicators. As your culture and processes improve, more of the continuous-improvement initiatives can shift to the plant floor. EP

Based in Knoxville, Klaus M. Blache is director of the Reliability & Maintainability Center at the Univ. of Tennessee, and a research professor in the College of Engineering. Contact him at



Klaus M. Blache

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