Condition-based maintenance (CBM) uses sensor devices to measure vital equipment parameters
Assets can be measured in a variety of ways (temperature, pressure, vibration, noise)
Maintenance work occurs as needed when a measured parameter signals an imminent fault
CBM systems can drastically reduce or even eliminate unplanned downtime
What is condition-based maintenance?
Condition-based maintenance (CBM) uses sensor devices to collect real-time measurements (ie. pressure, temperature, or vibration) on a piece of equipment. This data allows maintenance personnel to perform maintenance at the exact moment it is needed.
Condition-based maintenance workflow
Condition-based maintenance uses equipment measurements to perform maintenance only when that equipment may fail or needs repairs. You determine the precise maintenance point via visually inspecting a piece of equipment, performing tests on equipment specs, or gathering data and diagnostics. CBM allows maintenance personnel to act on a by-need basis, optimizing the amount of time spent on maintenance tasks.
This type of maintenance uses both condition monitoring and condition measurements. Condition monitoring measures specific equipment parameters (like vibrations in a system), taking note of drastic changes that could be indicative of a fault. Maintenance personnel take regular condition measurements from these parameters, which provides the current view of the equipment’s health. As equipment health dips, maintenance personnel perform work and return the equipment to its working state.
While CBM sounds similar to predictive maintenance, they aren’t the same: condition-based maintenance is less accurate than predictive maintenance because predictive maintenance uses complex formulas to figure out exactly when in the future maintenance will be needed. CBM doesn’t use these formulas; instead, maintenance takes place only when necessary based on condition measurements.
Condition-based maintenance is also not reactive because the equipment doesn’t need to break or fault to perform work. Maintenance work happens in response to measurements, not unplanned downtime events.
Benefits of condition-based maintenance
Condition-based maintenance has some distinct advantages other than only needing to perform maintenance work when necessary. These include:
- Improved equipment lifespan
- Reduced cost of equipment maintenance
- Improved prioritization and utilization of maintenance time
- Fewer unplanned downtime events, higher equipment uptime
Challenges of condition-based maintenance
It’s equally important to weigh the downsides of this kind of maintenance system as well as its upsides. Some downsides to consider are things like:
- Cost to install (typically expensive)
- Cost to train employees
- Extra costs to maintain and repair measurement equipment
- Difficulty in choosing proper measurement equipment
How condition-based maintenance decreases downtime
By monitoring equipment parameters in real time, CBM systems reduce downtime (and can even eliminate downtime as a whole). For example, your system measures the amount of noise produced by a motor, and a higher noise level indicates that the motor needs to be replaced. Because the equipment runs on a condition-based maintenance system, maintenance personnel will know exactly when to replace that motor because of this noise measurement. The moment the noise reaches an unacceptable level, the motor will be replaced.
That means you don’t need to wait until the machine faults out or the motor breaks and causes a massive downtime event. The unplanned downtime goes away, and in its place is maintenance work that takes place at a defined, measured point in time.
Example of condition-based maintenance
Condition-based maintenance works similarly to the warning lights in your car. For example, the oil light doesn’t pop up when your car is running on its last few drops. Instead, it conditionally measures the oil content of your car and lets you know when you need to change or replenish the oil. This information allows you to make an informed decision to maintain your vehicle.
This is true of manufacturing environments as well. If a machine produces a certain amount of heat under normal conditions but heats up quickly when an energy problem exists, an infrared camera can detect the change in heat and the system can dispatch a maintenance technician.
Another example is pressure readings. When a large amount of water flows through pipes, the water produces considerable pressure; fluctuations in this pressure can cause problems when water is needed (low pressure) or too much water is flowing (high pressure). Reliably diagnosing pressure issues can save a lot of headache in any industry that relies on water cooling systems.
Condition-based maintenance may seem too expensive for too little benefit. However, in any organization with critical equipment, a CBM system can prove its worth twice over when it comes to reducing or even eliminating unscheduled downtime.