Fixed-Time Maintenance (FTM) is an approach to preventive maintenance that involves scheduling regular, predetermined maintenance tasks at fixed time intervals. This can be a useful strategy for businesses that want to ensure their equipment is always in top condition and avoid any unexpected downtime. Maintenance teams often use this type of maintenance in industrial settings, where they need to keep machines up and running for long periods. FTM can be customized to meet the needs of each machine, and typically involves regular inspections, cleaning, and lubrication. By using FTM, businesses can avoid costly breakdowns and extend the life of their equipment. In this post, we’ll take a closer look at what FTM is and some of its benefits.
What is Fixed-Time Maintenance?
You may also use the term “fixed-time maintenance” to refer to time-based maintenance (TbM) or periodic maintenance. With fixed-time maintenance, regardless of an asset’s condition, you perform routine maintenance tasks at fixed intervals. By carrying out fixed-time maintenance, you can prevent failures before they occur and improve the performance of your assets.
FTM, however, does not always strike a balance between risk and reward because you can perform FTM regardless of whether the equipment needs it. For instance, your vehicle may have a manufacturer recommendation to change the oil every 5,000 miles. You can follow that fixed time interval, or, if you use high-quality oil, you may be able to extend your oil changes to 7,000 miles. Sticking to the fixed time of 5,000 miles regardless of oil condition will result in greater time and money spent, despite the reduction in failure risk.
The Pros and Cons of Fixed-Time Maintenance
Fixed-Time Maintenance Benefits
A maintenance management strategy that combines FTM with other types of maintenance can be beneficial. Here are a few benefits:
- Minimal Training – Time-based tasks do not require extensive training and are usually easy to learn.
- Lower Long-term Cost – Time-based maintenance is relatively inexpensive when compared to breakdowns or corrective maintenance (CM).
- Easy to Implement – Fixed-time maintenance requires no sensors or equipment before implementation, unlike predictive maintenance (PdM) or condition-based monitoring (CBM).
- Predictable Schedule – With fixed-time maintenance, you can have a consistent and predictable maintenance schedule.
- Effective for Continuously Running Assets – These assets have predictable wear rates, which makes them good candidates for fixed-time maintenance.
Fixed-Time Maintenance Disadvantages
If you rely heavily on fixed-time maintenance, you may face the following challenges:
- Neglects Causes of Failure – Fixed-time maintenance only focuses on asset and component age. But, the majority of equipment failure does not follow this rule or any predictable pattern.
- Greater Risk of Human Error – Frequent technician maintenance creates more opportunities for misalignment, incorrect reassembly, and other errors.
- Too Infrequent Schedule Leads to Excessive Failures – If you don’t find the right balance for your fixed time intervals, you may actually under-maintain your equipment.
- Ineffective for Assets Run Occasionally – When you only occasionally use a given asset, it will not wear down as quickly as those that you use continuously. As such, FTM is not ideal for all assets, but you can use it in conjunction with other preventive maintenance techniques.
- Increased Costs from Excessive Maintenance – Maintaining assets that don’t require maintenance leads to unnecessary downtime, labor costs, and consumable parts costs.
What is the Best Application of FTM?
A fixed-time maintenance approach is well suited for safety-related activities such as fire extinguisher inspections and smoke alarm tests. This is because safety-related failures are very costly, maintenance costs are relatively low, and condition-based maintenance (CbM) is either impossible or expensive. Fixed-time maintenance is also a great option for HVAC units, furnaces, and other assets that require seasonal attention.
FTM Must Be Fueled by Data
If you do implement FTM in your maintenance strategy, you have a few questions to address. How often do you schedule fixed-time maintenance tasks? How should you determine those frequencies? Most organizations set their fixed time intervals based on OEM (original equipment manufacturer) manuals or just have someone in the department create a schedule. However, a maintenance program’s success depends on determining the correct frequency of maintenance activities. You must use a combination of data to set your fixed-time maintenance intervals. This data includes asset management metrics such as mean time between failures (MTBF), historical maintenance data, manufacturer recommendations, and personal experience with your equipment. While FTM isn’t suitable for every facility, it can be useful in some cases with the right data.
