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We’ve all heard the phrase, “if it ain’t broken, don’t fix it.”
Fortunately, the inventors of the smartphone, the electric car, and central air conditioning never took the adage too seriously! Unfortunately, and somewhat ironically, maintenance managers often apply the advice literally to their detriment.
Studies suggest one hour of downtime costs industrial manufacturers between $10,000 and $250,000. Purely reactive maintenance programs are expensive, stressful, and time-consuming. This is why best-in-class maintenance departments aim to achieve an ideal ratio of 80:20 preventive maintenance (PM) to reactive maintenance. Strategic preventive maintenance programs have been proven to reduce unplanned downtime, increase operational efficiency, and reduce maintenance expenses associated with unplanned repairs.
Launching a successful preventive maintenance program from scratch involves several steps, including taking asset inventories, conducting criticality analysis, and determining key performance indicators (KPIs) to measure success. In this article, we’ll walk through the highlights with an emphasis on how to make preventive maintenance schedules for your organization.
How to Make a Preventive Maintenance Schedule
What Is a Preventive Maintenance Schedule?
A preventive maintenance schedule is a plan for organizing company resources to ensure maintenance tasks are performed according to specific time or usage triggers. The primary goal of preventive maintenance is to keep assets in optimal working condition.
Creating a preventive maintenance schedule involves coordinating materials, equipment, and timeframes for completing tasks. It also entails determining who should perform which tasks and how they should do it. Dedicated maintenance schedulers, maintenance supervisors, and maintenance planners are the team members most often responsible for developing PM schedules.
With that said, don’t confuse maintenance scheduling with maintenance planning. Though the two processes support one another, they aren’t always completed by the same individual. Maintenance planning focuses on what needs to be done and how. Maintenance scheduling, on the other hand, details who will perform recommended maintenance tasks and when.
Fixed vs. Floating Preventive Maintenance Schedules
Effective preventive maintenance schedules help facility managers efficiently allocate maintenance resources, effectively maintain assets, and appropriately plan for the year ahead.
When making a preventive maintenance schedule, you have two primary options: fixed and floating PM scheduling.
1. Fixed PM Schedules
A fixed preventive maintenance schedule is a routine maintenance plan scheduled according to specific equipment usage or time interval. Fixed PM schedules focus on future planned tasks, regardless of whether previous tasks were completed or not.
For instance, tasks scheduled on Mondays are always performed on Mondays regardless of whether your technician completed last week’s assigned task. Maintenance schedulers may also base recurring PMs on specific usage intervals or triggers.
EX: You schedule your fleet’s vehicles to undergo maintenance every 3,000 miles. Once an odometer reaches 3,000, you create a work order for a routine oil change and performance check. The vehicle’s next oil change will happen in another 3,000 miles. It doesn’t matter how long it takes your driver to reach the mileage. This is a fixed PM schedule based on usage intervals.
2. Floating PM Schedules
A floating preventive maintenance schedule is a maintenance plan based on the timing of previous PM tasks. Floating PM schedules are informed by an asset’s past usage or maintenance history.
For instance, assume you have a 30-day PM schedule for a machine. You will assign the asset’s next PM 30 days from the completion of the last PM activity. In other words, the subsequent work order won’t be triggered until the previous work order has been completed and closed. Floating PM schedules require greater diligence than fixed PM schedules for tracking maintenance task completion.
EX: You schedule an HVAC system for maintenance every 100 hours of operation. You delay maintenance until after the 120th hour. Therefore, your next work order will be triggered after 220 hours from the original PM. The system starts counting the 100 hours after the previous work order has been closed (at the 120th hour). If the HVAC system were on a fixed schedule, it would still get triggered for maintenance after 200 hours.
How to Make (and Implement) a Preventive Maintenance Schedule
The key to creating a successful preventive maintenance schedule is identifying the right maintenance interval for each asset. This allows you to maximize resources while reducing the chance of unexpected breakdowns.
Here’s our step-by-step guide for how to make an effective preventive maintenance schedule:
1. Inventory Assets
Create an inventory of your organization’s most crucial assets. These are the pieces of equipment that should receive preventive maintenance first and foremost. This exercise will help you avoid delaying maintenance for certain assets, especially if using a floating PM schedule.
Record the following data for each asset:
- Make and model
- Serial number
- Specifications and capabilities
- Unit number
- Primary users
You can use a spreadsheet or a computerized maintenance management system (CMMS) to catalog your asset entries. We recommend adopting a user-friendly platform like MaintainX to maintain asset records, cross-reference data, and glean cost-saving insights over time.
2. Determine Priorities
It’s important to remember that most of your facility’s assets don’t need to be scheduled for preventive maintenance. Exclusively performing PM on large asset inventories is unrealistic for most organizations. Additionally, performing PM on inexpensive, non-critical, and easily repaired items is wasteful. One way to determine PM priorities is to conduct a criticality analysis.
A criticality analysis is an exercise that involves ranking assets according to their risk potential in several categories, including operational, financial, environmental, and health and safety. This process is beneficial to organizations with several complex assets because it removes personal bias from the equation.
Criticality analyses allow managers to rank, prioritize, and schedule PMs with objectivity. Assets with higher criticality ratings should be given top priority. Use the following questions as a launchpad when evaluating asset criticality:
- Which assets are critical to production and safety?
- Which assets require regular maintenance?
- Which assets have high repair and replacement costs?
Prioritize assets that are critical to production, require regular maintenance, or have high repair and replacement costs when making your preventive maintenance schedule. Remember: it’s more cost-efficient to place non-critical and older assets on reactive maintenance programs. You might be replacing them soon, after all.
3. Identify Ideal PM Intervals
Of course, preventive maintenance isn’t without a potential downside. Without proper planning, you risk wasting precious resources on unnecessary inspections and repairs. Over-maintaining assets can be just as wasteful as under-maintaining them! Avoid overdoing it by identifying ideal PM ratios for your individual assets.
The three primary methods to determine PM intervals include:
- Consulting equipment manufacturer’s manuals for recommended maintenance work instructions, schedules, and usage of critical spare parts
- Reviewing historical maintenance data for insights into past failure patterns
- Asking machine operators and technicians for their insights into asset behaviors
4. Schedule Recurring Work Orders
According to the 2019 Plant Engineering Maintenance Survey, 45 and 39 percent of facilities still rely on in-house spreadsheets and paper records, respectively, for maintenance scheduling.
Little do these organizations know just how much easier the right CMMS can make their maintenance scheduling. Modern, cloud-based CMMS platforms are scalable, affordable, and user-friendly. The software allows you to automate both long-term maintenance schedules and short-term schedules based on quarterly, monthly, weekly, and daily tasks.
CMMS also allows you to capture minor maintenance activities that often fall through the cracks and go unnoticed. This enables teams to maintain backlogs at manageable levels. Additional features like inventory management, asset cross-referencing, work order commenting, team chat, and advanced reporting make MaintainX a game-changing tool for maintenance teams of all sizes.
5. Monitor Progress
Lastly, periodically monitor the progress of your maintenance schedules and identify areas for improvement. Most importantly, evaluate how many PMs your team has completed since creating your initial maintenance schedules. Additionally, several metrics are available to track the progress of your PM program, including:
- Mean Time Between Failure (MTBF): MTBF is the average time between asset breakdowns. Use MTBF to measure the performance, design, and safety of critical assets. The formula to calculate MTBF is: number of operational hours ÷ number of failures.
- Planned Maintenance Percentage (PMP): PMP measures how many scheduled maintenance activities have been completed compared to your overall number of maintenance tasks. Use PMP to measure the effectiveness of your PM scheduling and identify opportunities to minimize reactive maintenance.
- Scheduled Maintenance Critical Percent (SMCP): This metric measures how late a recurring maintenance activity is in relation to how often it should be done. SMCP helps determine overdue maintenance activities ripe for prioritization. The formula to calculate SMCP is: (number of days a task is overdue + length of the maintenance cycle) ÷ length of the maintenance cycle x 100.
- Preventive Maintenance Compliance (PMC): This metric measures how many scheduled tasks have been completed within a given period. It’s also useful for determining PM schedule effectiveness. The formula to calculate PMC is: number of completed PMs ÷ number of scheduled PMs x 100.
- Overall Equipment Effectiveness (OEE): OEE measures the level of productivity for an asset. It combines asset availability, performance, and production quality to determine the efficiency of an asset in production. An asset with an OEE of 100 percent doesn’t experience any unplanned downtimes (availability), produces as fast as possible (performance), and doesn’t have any defects (quality). Here’s an article on how to calculate OEE.
Use the metrics that most closely align with your O&M goals as benchmarks of success.
Final Tips for PM Scheduling Success
Preventive maintenance scheduling isn’t rocket science. However, several challenges can disrupt workflows, reduce schedule compliance, and create bottlenecks if not proactively navigated. Some common factors that disrupt PM schedules are:
- Poor team communication
- Inefficient maintenance inventory management
- Misunderstandings with third-party contractors
- Miscommunication with suppliers
- Lack of in-house skills for specialized tasks
Taking the time to develop centralized communication systems, employee continuing education programs, and clear standard operating procedures (SOPs) will set your team up for success.
Preventive Maintenance Schedule Template
Click here to download the template.
Simplify PM Scheduling with MaintainX
An effective preventive maintenance schedule will help improve the lifespan of critical assets, minimize operating costs, and significantly improve overall maintenance operations. We hope this article provided a simple path for developing effective PM schedules.
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