Whether you are a big or small company, a simple starting point for moving from a fire-fighting mentality to a more planned environment is to implement a preventive maintenance (PM) program. For starters, even a manual system at virtually no cost goes a long way toward making significant improvements to overall plant productivity. For less than $1,000, you can automate your PM program, eliminating some of the administrative tedium of a manual system and significantly improving the reporting. More expensive packages will provide even greater functionality, such as condition monitoring; for some, this may add significantly higher value such that its benefits outweigh the additional expense.

PM should be an easy sell — yet so few companies actually embrace it. Why, then, do so few people do these very simple PM routines even though they know it is good for them? Answer: Since there are no immediate consequences, PM becomes low priority.

It is therefore not surprising to find top management espousing the virtues of PM. After all, talk is cheap. However, the demands of production, and the expense in time and money of establishing and maintaining a PM program, cause an indefinite delay in the implementation of PM. Condition monitoring exacerbates the problem due to its even greater cost and complexity.

Features of Modern PM Systems
• Triggers: Because of its simplicity, the PM modules of CMMS packages share many basic features. All of them give you the option of triggering PM work orders based on calendar and meter readings. More advanced CMMS packages allow users to trigger PM based on events or condition readings taken from equipment on the shop floor on an online, real-time basis. These readings are compared to the allowable upper and lower control limits and can even spot an alarming trend before downtime occurs. Top-end packages can combine various indicators, setpoints and conditions using Boolean logic to create new triggers.

• Auto-reset: Suppose a PM is generated to change the oil based on the first trigger of a period of three months, a given usage meter reading of 3,000 kilometres or an event such as an overhaul. Regardless of which trips first, all appropriate triggers will be reset automatically with this feature.

Condition monitoring is an exception in that it could completely replace all of the other triggers. For example, suppose you are monitoring the level of particulate in the oil, and it trends outside an acceptable range thus triggering a PM to change the oil. Because the PM is triggered based on “true need,” there is no reason to reset or even have the other triggers. However, the downside to condition monitoring is that it is usually more difficult and more costly to implement; therefore, a business case is required.

• Calendaring: The calendar feature differs slightly from one software package to another in terms of ease of use and level of detail. High-end packages use graphics to display calendars showing holidays, vacations, shift hours and scheduled overtime for an individual tradesperson. Low-end packages dispense with the fancy graphics and may only provide calendars by crew or plant, not by individual. The calendar feature is important to achieve the objective of maximum tradesperson utilization.

• Seasonality: More advanced packages allow users to assign periods of time when a given trigger is or is not in effect. So, for example, a PM routine that is only relevant during the summer months can be blocked out from, say, September 1 to April 30. Some CMMS packages allow users to specify an unlimited number of exclusion periods or individual dates. A few packages will even let users specify a tolerance percentage and/or a preferred date for releasing a PM. For example, users might want to generate oil changes only on the first Tuesday of every month when the meter reading is within 10 percent of a given setpoint.

• PM shadowing: To avoid generating duplicate PM work orders, the PM shadowing feature skips over shorter-cycle jobs. For example, a major overhaul includes an oil change and will thus render redundant any oil changes scheduled immediately before or after the overhaul.

• Nested cycles: A feature found in only a few packages allows users to nest different PM cycles. For example, suppose the first cycle is to replace the oil and filter, and the second cycle the same. With nested cycles, users can set the third cycle as the same plus an additive and chassis inspection. This feature saves establishing three jobs instead of one job and three cycles. In turn, this makes changing a step easier by avoiding a change to all three jobs. You can also use nested cycles to handle PM shadowing and seasonality.

• Notification: This feature provides a notification or a warning of a trigger. Notification can be by email, pager, phone, screen popup, and so on. For the more advanced web-based CMMS packages, a shortcut to the status reporting or alarming screen can be included in the email.

• Integration: Another significant difference between CMMS packages with respect to their PM modules lies not within the module itself but in the ability of the package to interface with other software, such as document imaging, predictive maintenance, ERP, shutdown maintenance and project management software. Proper interfacing can dramatically reduce the amount of unplanned downtime experienced, as well as the length of downtime required for PM.

With the purchase of an optical scanner and/or using CAD software, document imaging allows users to attach either scanned or CAD images to a piece of equipment, work order or inspection record. These can then be retrieved within the PM module or other maintenance management modules for viewing, printing or editing. Thus, a maintenance worker can prepare a free-hand sketch of lubrication points on a piece of equipment and scan it, and the system will automatically print it each time the appropriate PM work order is printed.