Preventive maintenance allows you to maintain your goods and equipment so that they stay in the desired state while minimizing corrective maintenance. Preventive maintenance can be conditional or well planned.
A time-based maintenance plan for an asset, technical equipment or building consists of a library of specified maintenance work and a frequency of execution of that work. These maintenance frequencies are generally based on warranty conditions, supplier’s instructions, regulations or experience. An example of time-based maintenance is the periodic inspection of air-conditioning facilities: an annual inspection, filter cleaning every three years, and filter replacement every six years. Time-based maintenance sometimes occurs too late and causes an increase in corrective maintenance because the actual conditions of the element are not taken into account. And in some cases, it intervenes too early and not necessarily at the best conditions of asset management.
Condition-based maintenance is a method of maintenance using maintenance work order software that predicts when a good or equipment will fail, thereby avoiding the incident by performing the appropriate maintenance in time. Condition-based maintenance is applied to economic assets that can communicate their current status digitally to a maintenance system (Integrated Work Environment Management Solution, FMAO, and CMMS), in which the type and the time of maintenance are predicted based on limit values and previously set parameters. Through this continuous monitoring of the status of a property or installation, you get a “just in time” maintenance, which does not intervene too early or too late. This reduces maintenance costs to a minimum, avoids system failure and consequently reactive maintenance that can become costly.
A pre-defined maximum temperature value for your air conditioning is an example of maintenance based on the condition of the property. When the temperature of the installation exceeds this limit value, a preventive maintenance operation is generated to prevent the failure. The automatic planning of a maintenance operation when the number of hours of service of the installation exceeds the previously defined threshold is another example.
The benefits and application of time-based maintenance
The ability to schedule maintenance, as provided by enterprise asset management, is the main benefit of time-based maintenance over unplanned and responsive maintenance. Reactive maintenance often leads to overhead costs that can be avoided by maintenance planning. The costs of unplanned maintenance include production downtime, the economic impact of stopping production, the cost of replacement parts and the time lost due to communication and ineffective treatment. Comparative analyzes show that unplanned maintenance is typically three to five times more expensive than scheduled maintenance. When maintenance is planned, these operations can be performed outside production hours to minimize the economic impacts of non-production. Prior to production stoppage, spare parts, tools and resources can be organized to minimize the uptime of this maintenance. These measures reduce the costs of maintenance. In addition to reducing costs, business continuity is improved as equipment will be less likely to fail.
When compared to conditional maintenance, periodic maintenance does not require a monitoring strategy. This eliminates the need and costs associated with interpreting the data collected on the operating conditions and the implementation of the measures based on the results of this interpretation. However, maintenance can be excessive or insufficient if we stay on a planned maintenance strategy. Assets requiring time-based maintenance are assets that have a critical role for the business. Their failures or failures can be predicted by real-time monitoring and the risk of failure is not related mainly to time.