Condition Based Maintenance (CBM) is a technique to asset maintenance that makes use of real-time assessment of equipment or asset condition. Data obtained from embedded sensors, and external tests and measurements, is analyzed to identify equipment condition and the need for maintenance. Condition based maintenance lead to maintenance occurring just when there is a need.
There are three parts to condition based maintenance.
- Data collection
- Data analysis
- Maintenance demands decision-making
With condition based maintenance work is carried out just after the data shows the devices is approaching a point of failure, or that performance is deteriorating. By observing the condition of the devices with keeping track of real-time data, the very best time for performing maintenance can be identified. This reduces expenses, decreases spare parts stock, reduces devices downtime, and lessens the man-hours made use of for maintenance work.
Benefits of Condition Based Maintenance
Without trusted info, unnecessary maintenance work will be done, and required repairs will certainly be missed. A normal technique to determining what maintenance work is required is to look at historic trends and make use of that equipment history to predict what has to be performed in the future. While being of some help in identifying maintenance requirements, real-life aspects can lead to variances that cause failures sooner than predicted, or maintenance being done when it was not needed.
As sensors, instrumentation, and microprocessors have improved, the ability to detect, monitor and analyze real-time data has allowed equipment condition to be assessed on a continuous basis. This provides the information that makes condition based maintenance possible. The benefits include:
Condition Based Maintenance – Optimizes Equipment Use
Taking the example of a bearing: Condition based maintenance uses instrumentation to monitor bearing temperature and vibration. Oil from the lube oil return line is automatically sampled and analyzed to detect contaminants and evidence of bearing damage. Other conditions and stresses might be monitored and all of the data automatically analyzed to determine the real-time condition of the bearing. When monitoring shows signs that there is a problem with the bearing, appropriate corrective action can be scheduled. For example, increased bearing temperatures and metal in the oil may indicate excessive wear and the need to replace the bearing.
Because the requirement for maintenance can be detected in advance, maintenance can be scheduled at a convenient time that does not interfere with overall production. In addition, a catastrophic failure is avoided because maintenance can be scheduled before the problem becomes serious. This allows decisions about equipment scheduling to be made in a way that optimizes equipment use.
Condition Based Maintenance – Catastrophic Failures Are Eliminated
Needing to take machines or equipment out of service for maintenance at unexpected times, or having a machine fail and just stop working unexpectedly, not only results in a disruption to production, catastrophic failures can result in injuries or fatalities. In critical applications, such as medical or military equipment, an unexpected failure can be disastrous.
Condition based maintenance detects failure conditions before they result in a catastrophic failure. Even should there be a sudden failure, the condition leading to that failure can usually be identified in time to allow an orderly and safe shutdown of the equipment.
In addition, information from a condition based maintenance system can be used to detect when equipment or a system is approaching its end-of-life. This allows either a major overhaul to be scheduled, or the equipment replacement process to be started before the existing machine is taken out of service.
Condition Based Maintenance – Product Quality Is Improved
Small vibrations, misalignment, higher or lower than typical temperature levels are a few of the conditions that can impact the ability of devices to produce a quality output. These conditions can be spotted and fixed, lots of times by a basic change of an operating parameter, using the data from a condition based maintenance system. Data can be examined and used to fine-tune operating conditions to maintain product quality. In addition, by detecting and correcting maintenance issues early, product quality is kept and waste arising from out-of-spec item is removed.
Condition Based Maintenance – Unnecessary Maintenance Is Gotten rid of
Without real-time information, the scheduling of maintenance will always includes some uncertainty, even when historic records are used for scheduling maintenance. Some parts that do not need replacing, will certainly be changed, and at times the devices will be set up for maintenance when that maintenance is not needed. By having information about the actual condition of the equipment, maintenance can be scheduled when it is actually needed.
For example, a large machine might be undergoing maintenance on a regular basis every twelve months. Making use of condition based maintenance it might end up that a major overhaul just needs to be done extremely 15 months. That indicates that at the end of five years four major overhauls would have been done rather of 5 – a cost savings of 20 % just from eliminating unneeded maintenance work.
