A Short Guide to Preventive or Predictive Maintenance

379 days ago

Business of different types, sizes and purposes realise that maintenance costs are a necessary area of expense. In order to better plan and account for maintenance costs that will occur, it is advantageous to have an understanding of preventive and predictive maintenance. An understanding of these matters will help a business to better plan and prepare for maintenance and, as necessary, utilise maintenance software or a computerised maintenance management system (CMMS).

The Costs of Maintenance Management

Many businesses are surprised to learn that significant maintenance dollars are wasted through the use of ineffective maintenance management methods. The main reason for high maintenance costs is usually a lack of accurate and factual data to indicate when maintenance is required and the nature of the maintenance that is required – whether to maintain, replace or repair.

Too often, organisations fail to monitor the performance of equipment and systems, the maintenance that they receive, the occasions on which equipment has failed and other data that is pivotal for planning and scheduling tasks that prevent premature failures and increase the life and performance of the equipment used.  It is far more common for businesses to decide when and how equipment will be maintained based on opinion rather than factual data.

Maintenance Problems and Opportunities

The impact of random or inappropriate maintenance can certainly be felt in terms of:

• the quality of products and services
• inflated operating costs
• the level of profit achieved

The great news for businesses is that CMMS and sophisticated maintenance software offer a way for a business to enhance the effectiveness of its maintenance procedures and processes. For example, CMMS generate relevant historical data in a usable form and provide the means to increase the overall functioning and longevity of equipment, together with the lifestyle costs of the business’ facility and its assets.

Preventive Maintenance

Preventive maintenance is driven by time; this means that the maintenance tasks that are undertaken are time determined – the number of hours for which equipment has operated – together with statistics and historical data for different types of equipment and their need for maintenance. Mean-time-to-failure (MTTF) statistics can determine a preventive maintenance management schedule to include inspections, repairs and rebuilds.

One of the defining features of preventive maintenance is a scheduling guideline, whereby it is assumed that a machine will degrade within a time period that is common for its type. For example, a particular machine may typically run for 18 months before parts will need to be replaced. Under a preventive management approach, the relevant parts will be removed, replaced or rebuilt after 17 months of use.

The main issue with a preventive maintenance approach is that the way a machine is used, as well as a number of other variables, directly impact on the operating life of the machine. This approach can sometimes result in unnecessary maintenance but, if a part or an entire machine fails before it is due for maintenance, a run-to-failure approach is required, which can be expensive.

Predictive Maintenance

Predictive maintenance is determined by the condition of equipment rather average or expected life statistics. Essentially, direct monitoring and analysis of a machine’s operating condition, efficient working and other indicators reveals the need for maintenance tasks.

When a company uses a predictive maintenance program, it has access to relevant factual information about the operating condition of its assets and their efficiency, together with the impacts a particular machine has on an overall process system. Factual data can be used to plan and schedule maintenance tasks and the result of ongoing monitoring of condition and efficiency.

Predictive maintenance “…is a philosophy or attitude that simply stated uses the actual operating condition of the plant equipment and systems to optimize total plant operation.” Because a range of cost-effective tools can be used within a predictive maintenance program and to produce accurate factual data about pivotal systems, maintenance activities can be undertaken when they are most needed. Improvements in quality, profitability and productivity can result from predictive maintenance and maintenance costs can also be potentially reduced.

Because businesses want to ensure that their equipment runs smoothly and processes will not be hindered by machines or components breaking down, attention to the scheduling of maintenance is important.