Four general types of maintenance philosophies can be identified, namely corrective, preventive, risk-based and condition-based maintenance. Preventive maintenance aims to detect and fix problems before they occur. It is usually carried out in the form of regular inspections, which usually occur several times a year. The main benefit of preventive maintenance is that it can eliminate unplanned downtime, since the ideal is to detect problems before they occur.
Condition-based maintenance is sometimes considered a more advanced alternative to preventive maintenance. Instead of being inspected according to a schedule, machines and systems are carefully observed for changes that may indicate imminent failure. It is well known that billions of dollars are lost every year due to unscheduled downtime and poor asset quality. In an endless battle to combat this statistic, organizations implement one of a variety of types of maintenance, often combining two or more.
Definitions of types of maintenance vary by industry, which can make it quite confusing to differentiate between things like preventive and predictive maintenance, among others. Let's examine the most common types of maintenance used in the manufacturing and process industries. For an in-depth look at types of preventive maintenance, how to design a preventive maintenance program, preventive maintenance tools, and more, see the link at the beginning of this section. While many organizations employ both predictive and preventive maintenance (76 percent use preventive, while 65 percent use predictive, according to a recent Reliable Plant survey), there are some key differences.
In particular, preventive maintenance does not require the health monitoring aspect that predictive maintenance does. This means that predictive maintenance uses condition-based technologies such as infrared thermography, acoustic monitoring, vibration analysis and oil analysis. Another key difference is that preventive maintenance involves inspecting and maintaining assets regardless of whether the equipment needs maintenance (the maintenance program is based on a trigger). When it comes to maintenance types, techniques, and costs, the main types of maintenance can be compared to the human body to get a snapshot of the equivalent body maintenance task.
The following table uses an example of an energy generation asset and compares it to the human heart. Maintenance triggers can be configured and used with various types of maintenance. Failure triggers are used with reactive or run-to-fail maintenance plans. Predictive maintenance uses elements such as time-based triggers in the form of alerts to try to prevent a failure from occurring.
Other triggers that will be discussed include event-based, usage, and condition-based triggers. Just like your car changes oil every 5,000 miles, any machine that performs operations with time or quantity restrictions can be configured with a usage-based trigger. Meter readings can be added to a CMMS and used to set alerts when a desired quantity or value is reached. Usage-based triggers are a great way to keep equipment subject to irregular schedules and are most often used with predictive or preventive maintenance programs.
Technological advances are more prevalent in condition-based monitoring in the form of proactive and predictive maintenance. Under these types of maintenance, technologies such as oil analysis, vibration analysis, thermography and motor current analysis can help determine root causes and symptoms of failures, seek benefits such as extending machine life and early fault detection, and reduce the number and the impact. The current technological revolution in the manufacturing industry has led to fewer errors and defects, optimized production and reduced labor costs. Automated sensors that can continuously monitor machinery are among the biggest improvements.
Not only can they be used in various types of maintenance, but they can also generate a massive amount of data that can be analyzed and used to improve processes. This type of maintenance is performed by technicians in charge of industrial maintenance before any failure or malfunction occurs. Refers to spare parts, components and machinery and equipment to reduce the risk of failure. The digitalization of industrial enterprises has provided many IT and technology solutions that allow technicians to effectively perform, monitor, track and plan preventive maintenance.
The emergence of data processing and analysis solutions, as well as artificial intelligence, has allowed manufacturers to plan predictive maintenance based on the prediction of failures and malfunctions. This type of industrial maintenance allows companies to anticipate problems by planning necessary interventions and maintenance operations based on forecasts. In this way, you can limit expenses caused by unexpected breakdowns, equipment downtime and production interruptions. This type of preventive maintenance is distinguished by its frequency.
Technicians perform this regularly and systematically at well-defined time intervals beforehand. This allows components and spare parts to be replaced regularly, improving machine productivity. Therefore, systematic preventive maintenance is based on the regular inspection of the various equipment, which allows maintenance technicians to gather the necessary information about the various components of the production line and effectively prevent breakdowns and repair costs. Conditional preventive maintenance consists of monitoring the key parameters and indicators of the operation of the property and implementing the necessary corrective actions to anticipate any failure or malfunction.
There are many emerging IT tools available to automate this type of industrial maintenance. Thus, technicians and maintenance workers can simplify and facilitate their work by opting for the digitalization of industrial maintenance processes. Until recently, when talking about predictive maintenance (PDM), this was essentially synonymous with condition-based maintenance. Preventive maintenance can be defined as “an equipment maintenance strategy based on replacing or restoring an asset at a fixed interval, regardless of its condition.
When people talk about preventive maintenance (or preventive maintenance), they generally refer to what is best described as time-based maintenance (TBM). A CMMS is a really useful tool for maintenance teams, as they enter every detail of their interventions and exchange with their colleagues to keep track of all operations, maintenance plans, etc. This is because this type of maintenance does not go through the scheduling process of full maintenance planning %26 because it is very urgent and is simply planned on the fly. Predictive maintenance requires a level of technology that standard preventive maintenance does not require, and may also require employees who can accurately interpret condition monitoring data.
However, since I am often asked questions about the different types of maintenance, I decided to give a quick summary of the types of maintenance. A next-generation CMMS such as Mobility Work, a solution that offers a performance analysis tool capable of collecting all the data entered by the maintenance teams themselves, aims to progressively help plants evolve towards predictive maintenance. Among all the types of maintenance mentioned above, condition-based maintenance is the most complicated to implement. But, in many people's minds, fault maintenance is urgent maintenance, maintenance that needs to be done right now.
Regardless of the decision you make, you need to provide maintenance teams with maintenance management software to ensure proper supervision of interventions, as well as smooth communication between technicians and other professionals. If you have resource constraints, you need to ensure that you have high productivity during execution (read my articles on maintenance planning, scheduling %26) and that you don't waste your scarce resources on preventive maintenance tasks that add no value (read my article on the principles of modernity maintenance). For example, during a scheduled maintenance check or while another problem is being fixed, a service technician realizes that a pipe in an HVAC system is not working as it should. Instead, download The Types of Maintenance Tool Kit and learn what type of maintenance to use and when.