Five steps to applying predictive maintenance

The following steps are predicated on the assumption that all assets in a facility have been identified within a functioning PM program that uses a computerized maintenance management system (CMMS).


Ensuring the right work is performed at the right time to minimize downtime on production assets is crucial to productivity, but avoiding costly unplanned maintenance is paramount as well. It can be expensive to remove a piece of equipment from production to perform routine preventive maintenance, only to find a function dictated by the Preventive Maintenance (PM) task was not necessary. Predictive Maintenance (PdM) is based on the operating conditions of the asset and the set parameters of its function, rather than time- or calendar-based PMs.

The following steps are predicated on the assumption that all assets in a facility have been identified within a functioning PM program that uses a computerized maintenance management system (CMMS), which includes all planned and unplanned maintenance activities, labor and material costs accurately.

1. Follow the dollars

First, you need to determine where financial and human resources are expended and itemize the assets that are vital to your process. Concentrate first on assets lacking a spare. Aircraft manufacturing is one of the few industries where multiple redundancies are engineered into a product. Chances are, you have a few backups such as supplementary pumps for critical processes. But no one can afford an idle production line just in case it is needed if something breaks down on the primary line.

Using data extracted from the CMMS, identify the high-cost and/or frequent incidents that are consuming the maintenance budget and generating lost production. Examine 2to 3yrof data to ensure all potential issues are addressed. Include the cost of lost product, whether it's pieces, cases, gallons, or tons. Many times these costs are neglected in the calculations, and an important piece of the cost picture is lost. Occasionally, the cost of lost product exceeds that of the repair itself. Just because an incident has a low occurrence rate doesn't mean it should be discounted from a PdM program.

2. Perform analysis

Once you have identified the bad actors by cost/frequency, conduct an analysis to examine the mean time between failure/rate (MTBF/R), and identify whether the mean time is increasing or decreasing. Perhaps you've already undertaken some remedial actions and improved the MTBF/R on a particular unit. However, don't dismiss these incidents even if the number of incidents is decreasing. The time and costs consumed can still be significant and warrant investigation

3. Determine where to use PdM

Some assets are, and will generally be expendable and can be run to failure. A ¼-hp motor on a conveyor segment comes to mind. These motors are likely in stock or can be obtained quickly and easily. However, a 200-hp dc motor on a reversing rougher in a steel mill would be a prime candidate for PdM, as well as its gearbox.

The intent is to identify the assets that would cause a catastrophic impact should they unexpectedly fail. While some assets will immediately come to mind, others may come as a surprise as to their difficulty to detect an impending failure.

To better understand where PdM should be deployed, a failure mode effects analysis (FMEA) exercise should be conducted, with the equipment ranked by their susceptibility of failure based on severity, occurrence, and detection criteria. This will generate the risk priority number on which to prioritize the assets. This requires accurate data from a CMMS to trace past breakdowns.

4. Define the technologies to be used

Not all machines need be included in PdM strategies. However, rotating equipment, gearboxes, and electrical distribution components are prime targets for PdM. Vibration monitoring, oil/wear particle analysis, and thermography are the most prevalent PdM strategies deployed, regardless of the industry. Bearing temperature analysis is also a common tool. The failure that the site is attempting to detect drives the technology employed.

Obviously, there is an initial investment to acquire the needed technology and tools to implement PdM. Prudent research and common sense need to be applied. For example, only one infrared thermography camera needs to be purchased, as it can be used sitewide. The same would be true for vibration monitoring, since a portable unit can be used throughout the facility. Generally, oil analysis is conducted offsite by a firm specializing in tribology, sometimes by the actual oil vendor.

Another factor to remember is training staff in using data collection tools and data analysis. Acquisition of data is meaningless unless there is trained staff to analyze and interpret the results, and actions are taken to correct the potential failures identified. If a site is not going to train staff or use the information obtained, it is better off outsourcing the PdM function.

5. Deploy tools

After the tools have been purchased and the staff trained in their use, you can acquire the initial baseline data and capture the results in the tracking program to plot it against performance standards developed by the site or manufacturer. These results should be continually plotted on an asset deterioration curve. Many software packages are available that will perform this function. Bear in mind, the validity of a deterioration model is based on the accuracy and reliability of the data employed.

When the impending failure has been detected, planning should begin to address the problem at the appropriate time, based on production, business conditions, and the amount of deterioration revealed. A technological strategy for today's high-tech equipment is a sound approach to maintaining assets with minimal production loss. A PdM program can reduce costs and downtime to undertake inspections, as it uses noninvasive tools and procedures without interrupting production. Assets that are properly monitored and maintained via PdM rarely fail and generate unplanned downtime. PdM has the potential to generate savings of about 30% in maintenance expenditures. Too little or too much maintenance is avoided, freeing staff to pursue other activities such as reducing the backlog or performing capital projects.

What's not to like about that?

Mike Johnston, CMRP, is a senior consultant for T.A. Cook.

The Top Plant program honors outstanding manufacturing facilities in North America. View the 2015 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
Pipe fabrication and IIoT; 2017 Product of the Year finalists
The future of electrical safety; Four keys to RPM success; Picking the right weld fume option
A new approach to the Skills Gap; Community colleges may hold the key for manufacturing; 2017 Engineering Leaders Under 40
Control room technology innovation; Practical approaches to corrosion protection; Pipeline regulator revises quality programs
The cloud, mobility, and remote operations; SCADA and contextual mobility; Custom UPS empowering a secure pipeline
Infrastructure for natural gas expansion; Artificial lift methods; Disruptive technology and fugitive gas emissions
Power system design for high-performance buildings; mitigating arc flash hazards
VFDs improving motion control applications; Powering automation and IIoT wirelessly; Connecting the dots
Natural gas engines; New applications for fuel cells; Large engines become more efficient; Extending boiler life

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
The maintenance journey has been a long, slow trek for most manufacturers and has gone from preventive maintenance to predictive maintenance.
This digital report explains how plant engineers and subject matter experts (SME) need support for time series data and its many challenges.
This digital report will explore several aspects of how IIoT will transform manufacturing in the coming years.
Maintenance Manager; California Oils Corp.
Associate, Electrical Engineering; Wood Harbinger
Control Systems Engineer; Robert Bosch Corp.
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
click me