What is Preventive Maintenance?

Preventive maintenance (PM) is the regular and routine maintenance of equipment and assets in order to keep them running and prevent any costly unplanned downtime from unexpected equipment failure.

A successful maintenance strategy requires planning and scheduling maintenance of equipment before a problem occurs. A good preventive maintenance plan also involves keeping records of past inspections and the servicing of equipment.

Because of the complexity of maintaining a preventive maintenance schedule for a large amount of equipment, many companies use preventive maintenance software to organise their required preventive maintenance tasks.

What are the Types of Preventive Maintenance?

PM is used to anticipate and prevent the breakdown of equipment and should ideally be performed on all items of equipment to prevent age-related failure. Manufacturers often provide recommendations to maintain a piece of equipment but, generally speaking, there are three main types of preventive maintenance task:

Mandatory / Non-Mandatory Tasks

Mandatory tasks are those that must be performed as soon as they are due and will often include safety-critical checks. Non-mandatory tasks are still important, but can be delayed without resulting in a critical failure or performance reduction. A preventive maintenance checklist should split tasks into mandatory or non-mandatory.

Pyramiding / Non-Pyramiding Tasks

Pyramiding tasks occur when maintenance is set for a due date but is not completed and overlaps with a later scheduled maintenance. In this instance, should a new PM task become due, the previous one is cancelled. A cancellation should include a note to explain this and the new task should include the original due date to monitor how overdue the task is. Some companies prefer a non-pyramiding structure, which removes the need to note the original missed task and just takes the new date as the baseline.

Inspection and Task Oriented Tasks

Inspection tasks require checks to be made before the results are turned into work orders for planned maintenance to fix any problems that have been discovered. Task oriented PMs allow for minor repairs and adjustments to be made at the time of inspection, reducing the amount of work that needs to be written up as work orders on the inspection sheet.

When is Preventive Maintenance Required?

The exact requirement for preventive maintenance will vary depending on the equipment and the operation it is performing. Industry uses standards to help determine schedules for maintenance so that assets do not run to failure. These guidelines will also cover the type of inspection or maintenance that is needed.

Ideally, by following guidelines set down by manufacturers or standards, a PM schedule should ensure proactive maintenance rather than having to resort to reactive maintenance when something has already begun to fail.

Following this type of predictive maintenance schedule, through tasks such as condition monitoring, requires accurate recording of inspections and servicing against an understanding of the lifespan of a particular piece of equipment. These records will help determine when preventive maintenance is required.

Why is it Important?

Preventive maintenance provides companies with several important benefits related to costs, errors, and health and safety. These benefits include:

Improved reliability and life of equipment
Fewer costly repairs and downtimes associated with unexpected equipment failure
Fewer errors in operations as a result of equipment working incorrectly
Reduced health and safety risks

A good PM schedule should prevent equipment from failing unexpectedly, reducing cost, saving time, and ensuring your operation continues to run smoothly, efficiently and productively.

Advantages

Preventive maintenance offers several key advantages for businesses, including:

1. Improved Safety

Maintaining assets prevents potentially dangerous failure, mitigating against injury and any associated liability lawsuits.

2. Greater Equipment Lifespan

By making sure equipment runs according to guidelines you will help improve the lifespan of the asset. Failing parts reduce the life of your equipment, resulting in expensive repair or replacement.

3. Improved Productivity

Statistics show that poor maintenance can reduce a company’s production capacity by 20%. By meeting maintenance requirements, you can prevent this fall in productivity as well as reduce downtime to enable greater efficiency and productivity.

4. Reduced Costs

It is estimated that running a piece of equipment to failure can cost ten times as much as performing periodic maintenance. The expense comes as a result of unexpected downtimes and repairs. By understanding the maintenance requirements, you can schedule necessary repairs or part replacements at a suitable time, whether that can be achieved internally or requires an outside professional.

5. Reduced Energy Consumption

PM can also have an environmental benefit, since poorly maintained electrical assets tend to use more energy than those that are functioning correctly. Of course, there is also the financial benefit of lower energy bills as a result.

Disadvantages

While the advantages of preventive maintenance are clear, there are a few potential challenges associated with a PM schedule:

1. Budget Constraints

Some smaller businesses have found that advanced digital maintenance solutions are expensive due to high price software and the cost of hiring external experts. Such budget issues have meant that some consider PM to be a luxury rather than a necessity. Fortunately, this situation has begun to change in recent years as more affordable options are entering the market.

2. Additional Resources Required

Completing preventive maintenance may require more staff, parts and time. This requirement means that some companies will focus their preventive maintenance on essential, business-critical assets only.

3. Time-Consuming

As mentioned above, PM can be time consuming. Inspection of complicated equipment can be a laborious task, which can lead some to try to skip some routine inspection and maintenance jobs.

4. Organisational Difficulties

Organising your preventive maintenance can be difficult, especially if you have hundreds or thousands of assets to maintain. These difficulties are, however, greatly reduced through the use of a maintenance software program. A dedicated PM program cuts out the need for binders of paper and people remembering what should be done, and when.

Examples of Preventive Maintenance

Preventive maintenance requirements differ depending on the equipment being maintained. Example tasks may include cleaning, lubrication, replacing or repairing parts, or even partial or complete overhauls.

More obvious examples of preventive maintenance include ensuring production line equipment is working efficiently or heating, ventilation or air conditioning elements are inspected, cleaned and updated.

However, other areas in a business also require regular maintenance. Water supplies need to be sanitary, electrical systems have to be safe and compliant with legislation, and doors, lighting and flooring also needs to be checked to ensure they are all working correctly and not potentially hazardous.

Software

As highlighted above, PM software can greatly simplify the coordination of your preventive maintenance tasks. Good PM software will be able to track and store your preventive maintenance requirements and data. This can make it easier to manage work orders, purchases, inspection records and inventories.

Preventive maintenance software can prioritise your tasks as well as offering the information required for work to be completed. A PM program can also plan when tasks should take place based on your operational needs, thereby reducing disruption to your work schedules.

What is the Difference between Preventive Maintenance and Corrective Maintenance?

Corrective or reactive maintenance is when you wait for a problem to occur before addressing it. Often a small problem will go unnoticed until it becomes a larger issue. This is called the ‘run to failure method.’

However, this type of corrective maintenance isn’t cost effective, as it increases unexpected downtimes, which can incur unplanned expenses. These expenses can go beyond the cost of repairing or replacing equipment to also include lost productivity and overtime labour costs to meet deadlines.

A run to failure working model could also cost you reputation if your lack of PM means you cannot complete work on time for a client or customer.

What is the Difference between Preventive Maintenance and Predictive Maintenance?

Predictive maintenance (PdM) is an advanced form of preventive maintenance that aims to reduce the number of planned tasks in a PM schedule.

PdM analyses data collected from experts, equipment readers, and past experience to determine when specific conditions have been met. Increasingly, Industry 4.0-based Internet of Things feedback is also being used to inform PdM and help further optimise PM requirements.

While the cost, complexity and time taken to gather data can prove a barrier to the widespread adoption of PdM, a well-informed system will enable more financially sound decisions to be made for the ongoing maintenance of your assets and equipment.