Larger, more sophisticated manufacturing companies have been enjoying the benefits of condition based maintenance practices for many years. Unfortunately, the cost of purchasing analytic equipment, training and implementing these programs have prevented many small and mid sized companies from gaining traction in this cost saving methodology. New technologies on the market today are changing this dynamic creating opportunities for all maintenance departments, large and small, to reap the rewards of a more proactive strategy.
Before exploring some of these new products lets first define some terms that are used by reliability professionals, sometimes with great debate as to their differences. For this discussion, we will assume the following:
Preventative Maintenance (PM) – the practice of taking proactive steps to prevent asset failures and unplanned downtime. These could be time based or condition based in nature but the end goal remains the same.
Predictive Maintenance (PdM) – an element of preventative maintenance that uses historical performance or operating condition data to predict when an asset will reach functional failure.
Condition Based Maintenance (CBM) – the practice of periodic or continuous monitoring of an asset's health through temperature, vibration, sound waves, power usage and other methods to help make decisions on when to perform repairs or maintenance.
Simple time based PM is a common practice that consists of adding lubrication, cleaning, checking tightness, etc. Most companies employ at least some form of this even if it’s not consistently carried out. The problem with time based PM, in addition to getting skipped if there are other “fires” to put out, is that you may be lubricating an item that doesn’t need it wasting time and lubricant. In the case of certain equipment such as an electric motor you may end up hastening its failure rather than preventing it.
This is where condition monitoring comes in. You might say, “We monitor the condition of assets, when the bearing starts squealing we tell production we need to shut the machine down and fix it.” Okay, technically that fits the definition. But production may say that you can’t take it down for two weeks – or more.
Two days later, in the middle of the night, you get that dreaded call. The machine is down; it’s costing $2000 every hour, customer orders are now behind and it’s your fault. Sound familiar? This is where asset heath condition monitoring can provide a different outcome. That squealing bearing was giving clues many weeks or even months prior. Using devices that can pick up these clues gives you more time to plan.
Up until recently the only way to do this type of condition monitoring was to spend $30,000 - $40,000 or more on equipment, $5000+ on training and then prioritize what needs to be monitored. Then hope that cutbacks or the person who received the training leaving for greener pastures doesn’t sidetrack your efforts. Far too many companies have equipment sitting on a shelf somewhere that no one knows how to use or exactly what it does.
There are other ramifications of not doing condition based monitoring that make the investment given in the previous example a bargain. It’s possible that the machine failing could present a health risk. There’s the cost of downtime from production lost and idle employees. Oh, and if that bearing is squealing chances are good there will be expensive damage to it's housing or shaft. But still, convincing management of this can be challenging.
Today there are new options with a smaller upfront investment. An entire industry of outside companies has cropped up that will come in and provide maintenance and reliability services. These companies will consult with you to develop an in-house program or provide a turn key solution where they do the monitoring and simply make you aware of troubling equipment trends. Even still, there will be a cost involved in setting up the program as well as the ongoing monitoring. Getting management to understand that this cost is an investment and not an expense can be difficult especially when cash is tight even though it will improve the company’s financial position in the long term.
There is also a new group of products coming to market now that provide a low-cost point of entry and are very simple to operate. One of these is the i-ALERT2 from ITT. They mount on a pump, motor or other moving piece of equipment and continuously monitor the equipment health. There is a simple interface via Bluetooth to a smartphone or tablet application that allows you to create routes, collect data or simply set alarms that warn you very early that things are moving towards failure. Bearing companies and motor manufacturers are coming out with similar products. In many cases these solutions can be implemented for under $500 per monitored point.
For more critical applications or for those companies that can not or do not want to monitor things themselves, cellular or internet connected devices can provide off site monitoring and alarming capability. There are forward thinking companies developing algorithms that predict when an asset will fail from the collected data. The information gathered can then be combined with data from similar applications worldwide to improve the accuracy of the predictions. This sophisticated form of predictive maintenance will maximize asset operating life while reducing unnecessary repairs.
To remain competitive in a global economy, companies must find new creative ways to maximize productivity and efficiency in operations. Eliminating unplanned downtime and reducing repair costs is a great place to start. Condition based preventative maintenance along with predictive strategies provides the tools to help make this happen.