Tailor your maintenance program for each asset

David Berger says optimize your maintenance program for different work types.

By David Berger, P.Eng., contributing editor

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Your CMMS is a marvelous tool for planning and scheduling maintenance activities, as well as tracking your maintenance history. But one of the greatest strengths of your CMMS is often underutilized — the ability to optimize your maintenance program for all of the relevant work types.

Maintenance management, along with maintenance planners if you are large enough to cost-justify them, must determine the best mix of breakdown, preventive, predictive, and non-maintenance work, whether the work is done internally or using outside vendors.

Define work types

There are only three possible maintenance policies that define how all maintenance work is initiated, regardless of the asset class.

Failure-based maintenance: This maintenance policy is triggered by a mechanical breakdown or failure of some kind, such that the asset is not fulfilling its intended purpose. For example, replacing light bulbs when they burn out would be considered failure-based maintenance.

Use-based maintenance: When maintenance is triggered by an interval of time or meter reading, or by the recurrence of a given event such as a rainfall, then it is considered use-based maintenance. An example of this maintenance policy is replacing light bulbs in your facility on a rolling cycle of, say, once every year.

Condition-based maintenance: The third way maintenance can be triggered is by satisfying one or more conditions, such as reaching or exceeding an upper or lower control limit, or matching a specific trend or pattern. Following the theme above, an example of this policy is replacing light bulbs when the electrical resistance or heat output is measured and reaches a given set point, meaning the light bulb will be failing soon. Condition monitoring can be online real-time, or part of a regular manual inspection using appropriate handheld equipment.

Maintenance personnel also perform non-maintenance work with such work types as follows.

Capital projects: When assets are added or modified in a significant way, maintainers are frequently asked to help with the project. Participation in planning and executing capital projects can be useful for the maintenance department, given that they are the most likely recipients of the workload that will surely follow, to maintain the new or modified assets.

Demand work: Although this term is used loosely in most companies, demand work should really refer to tasks that are requested by the internal or external customers and that are neither maintenance work nor capital projects. This includes tasks such as moving a piece of equipment, fabricating a simple jig, or assisting with a production changeover.

Area assurance: This very unproductive work type is relevant to maintenance personnel who must be physically available to react to downtime or maintenance requests emanating from a given area. For example, operations may insist on having an area mechanic that is given few or no distractions, such as other work types. If the equipment jams or a component fails, the maintainer responsible for area assurance will spring into action and resolve the problem. Operations might be perfectly happy to see the maintainer sitting around and reading the paper all day, because it means uptime was maximized.

This work type was made famous by the lonely Maytag repairman commercials of the past 30 years, which implied that the ultimate image of success for a maintenance department is maintainers sitting idly with equipment always running. But why not maximize uptime and minimize maintainer idle time while on area assurance? The two are not mutually exclusive.

Optimize your maintenance program

To get more out of your CMMS, determine the optimal maintenance policy for each asset or component, starting with assets and components that have the most catastrophic consequences if they fail — your critical assets. Determine which of the three maintenance policies yields the greatest benefit at the lowest cost. If consequences of failure are extremely high, consider installing redundant equipment. This works well if the cost of redundancy is outweighed by the benefits of lower risk of failure.

If redundancy proves too expensive an option for critical equipment, explore adopting condition-based or use-based maintenance policies. As in the light bulb examples, condition-based maintenance policies are typically the more expensive route to implement. However, the higher cost of fully automated or even manual condition inspections may be outweighed by the lower risk of a costly failure. This, of course, assumes that the condition monitored is an accurate predictor of failure and that there is adequate time and means for taking action when an alarm is triggered. Sometimes, multiple conditions require monitoring to improve the accuracy of predicting failure, which, in turn, may affect the cost effectiveness of a condition-based maintenance policy.

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