Homyze provides a guide on what is planned preventative maintenance (PPM) and how to go about implementing this maintenance strategy
Choosing a maintenance strategy
Maintenance strategies are a balance between the costs of maintenance and the costs of downtime or failure. Here are some things to consider.
Choosing the right maintenance strategy for a company's assets and properties can be challenging. We are often faced with the dilemma of choosing between reliability and profitability. In this article, you will learn useful guides on deciding a maintenance strategy for your assets.
Before going further, it is important to understand why a piece of equipment might fail in the first instance. The most common reasons for equipment failures are highlighted below:
- Exceeding preset capacity limits by overworking equipment.
- Wear and tear, e.g., surface degradation due to corrosion and rusting, physical damage e.t.c.
- Non-adherence to maintenance instructions or lack of preventive maintenance.
- Error during installation or design.
- Misuse and mismanagement.
- Improper storage.
- Unskilled operators.
While some approaches to equipment maintenance are universal, some are unique to specific equipment. The nature of a piece of equipment to be maintained will determine the type of strategy to be implemented. Other factors that could also influence our choice include:
Value of equipment
Not all the equipment in a facility has equal value. Routine equipment is handled differently to special or business critical equipment. In the same vein, more expensive and sophisticated assets will usually cost more to maintain than the less expensive ones.
Cost of equipment failure
In the event of an asset breakdown, what effect will it have? This can be evaluated in terms of equipment downtime. Essentially, this refers to the time that a piece of equipment is not in use due to a defect or scheduled maintenance activities. It makes sense that if equipment downtime will cause a significant loss of revenue or if the costs of repair are enormous, a strict maintenance strategy will be adopted.
Cost of monitoring
Maintaining a piece of equipment comes at a defined cost. If the cost of monitoring a given asset is close to or exceeds its repair or replacement, such maintenance may not be worth implementing.
Planned versus Reactive versus Predictive
The maintenance strategies list is hardly exhaustive as different approaches can be mixed and matched. Here, we will discuss three common types, their benefits, and when they are most suitable.
This is a proactive approach to asset maintenance as these maintenance tasks are scheduled to be performed regularly. The type and frequency of maintenance are predetermined according to the nature of the equipment under maintenance and company policy.
An example is changing the machine oil at the end of each month. Planned maintenance ensures that assets, or their components, operate smoothly for a long time.
This type of maintenance strategy is also referred to as breakdown or run-to-failure. In simple terms, it means the habit of fixing things when they break. In other words, you wait for your equipment (or part of it) to fail, and then you correct it.
Reactive maintenance is the simplest as it does not require elaborate planning. Here, it is assumed that as a piece of equipment ages, one or more of its components will eventually fail. A simple example would be changing a busted light bulb.
These kinds of failures do not significantly affect operations, and they can be easily fixed. However, adequate care must be taken when implementing this strategy because the negative impact can be substantial if misapplied. Generally, this method is most suitable for equipment that is not essential for operations or is easy to replace.
This is arguably the most advanced maintenance strategy. It involves predicting failures before they occur so that maintenance can be done promptly. In some cases, predictions can be made through visual inspections of critical functions of an asset. However, the mainstay of predictive maintenance is the use of sensors to track an asset's condition in real-time and performing maintenance in advance.
The condition of equipment can be monitored using any of the following methods:
- Vibration analysis: Use of vibrations to detect equipment failures. The maintenance team is alerted, and appropriate measures are taken.
- Thermal imaging: Infrared cameras can be installed in machines to detect abnormal rises in temperature.
- Oil analysis: The condition/quality of oil therein is used to predict the state of the equipment.
- Acoustic analysis: Employs the use of sonic or ultrasonic devices to detect changes in the condition of equipment, such as leakages.
Predictive maintenance is expensive to carry out and requires a special skill set. Ideally, it is most suited for more sophisticated machines.
Benefits of different strategies
Benefits of planned maintenance
Planned maintenance comes with numerous benefits. Many of these are associated with the possibility of flexible scheduling. For example, maintenance can be fixed for a time when there is less activity such that there is no interference towards normal operations. Other benefits include:
- Reduction in cost of repair.
- Resources such as tools and workforce are used efficiently since maintenance work occurs regularly over a long period.
- Reduced risk of equipment failure thereby reducing equipment downtime.
The major drawback of this method is the inefficient use of resources since maintenance is carried out based on schedule rather than when needed.
Benefits of predictive maintenance
Predictive maintenance ensures that more accurate decisions are made since real-time data about the condition of the equipment is readily available. Other benefits include:
- Fewer equipment failures.
- Sensors can be used to verify the completion of repair.
- Access to precise data and a holistic view of asset health.
- Reduction in unplanned downtime.
- Better equipment quality.
- Significant cost savings.
The challenges of implementing this strategy are higher initial costs, high tech and trained workers are required - if data is misinterpreted, wrong decisions about asset condition are taken and this could be costly.
Benefits of reactive maintenance
Asides from the simplicity that comes with reactive maintenance, it also ensures that equipment is utilised maximally. Other benefits include:
- Reduction in initial costs since there are no preventive measures in place.
- Since equipment failure is unpredicted, no planning is required.
- Fewer workforce needed.
The challenges of this strategy are increased asset deterioration, longer equipment downtime, and an approximate maintenance budget.
Developing a maintenance strategy
In reality, there is no specific strategy that fits all instances. In developing a strategy, the benefits and drawbacks of each method are evaluated and compared against the type of assets in question, the organization's policy, and the potential impact of equipment downtime. The following are useful sequential guides in determining the right strategy for you:
- Put together a maintenance team consisting of personnel from different departments.
- Evaluate the potential impact of equipment failure on operations.
- Determine the costs of the different strategies.
- Determine the most suitable strategy for your equipment based on your findings.
- Implementation of the chosen strategy.
- Monitor the efficiency of the chosen strategy and make necessary adjustments.
Developing a suitable maintenance strategy for your assets is necessary to guarantee optimal performance and improve overall efficiency. In choosing a strategy, a balance should be struck between profitability and reliability.
If you would like to discuss planned, reactive, predictive, or other maintenance strategies, get in touch.