The basic pillars of TPM and their relationship to an RCM strategy:
TPM calls for restoring equipment to a like-new condition
Operators and production staff can contribute substantially to this process. At the same time, according to RCM studies, up to 68% of equipment failures can occur in the infant mortality mode, at installation and start-up, or shortly thereafter. Good TPM practices will help minimize this through restoration of equipment to like new condition and operator basic care.
However, it is often the case that more advanced practices may need to be applied, such as a stringent commissioning of the equipment, as well as the process. The use of condition monitoring tools on startup to establish standard performance for PdM methods is a preferred technique. Technologies such as vibration, oil analysis, infrared, mechanical ultrasound, can be used to verify the like new condition. It may also be especially important to understand failure modes and effects to take steps in both operations and production to mitigate or eliminate those failure modes.
Many will say that TPM calls for application of predictive maintenance, or condition monitoring. However, this tends to be quite limited and usually only involves operator “condition monitoring,” e.g., look, touch, feel, etc., certainly good practice, but at times insufficient. Further, condition monitoring as practiced under TPM may not have a strong foundation, such as a failure modes analysis, which drives the specific technology being applied. For example, reasoning such as “it’s a bearing and we do vibration analysis on bearings” without defining weather the failure modes require spectral, overall, shock pulse, etc. techniques, may not provide an adequate analysis method for the machinery in question.
The RCM process will identify the failures that can be prevented with typical TPM operator care techniques. Many failures modes can be detected early with proper written inspection techniques and practices. RCM processes get operations and maintenance working together more effectively and improves the communication process between the groups.
TPM calls for operator involvement in maintaining equipment
This is a must in a modern manufacturing plant. However, the operator often needs to be able to call upon specialist in more advanced technologies, when a problem starts developing in the equipment. These specialists can use RCM principles such as failure modes and effects analysis, as well as condition-monitoring tools, such as vibration analysis, to identify and prioritize problems, and get to the root cause.
The foundation of a good RCM process is to ask the question on every failure:
- Can the failure be predicted using some technology?
- Can the failure be prevented using a PM types task/inspection?
- Can the failure be eliminated by a re-design?
TPM calls for improving maintenance efficiency and effectiveness
This is also the hallmark of RCM. Many plants make extensive use of preventive maintenance or so called PM’s. However, while inspection and minor PM’s are appropriate, intrusive PM’s for equipment overhaul may not be, unless validated by equipment condition review, because according to RCM studies little equipment is truly average. RCM helps determine which PM is most effective, which should be done by operators, which should be done by maintenance, and which deserve attention from design and procurement. PM’s become more effective because they are based on sound analysis, using appropriate methods.
TPM calls for training people to improve their jobs skills
RCM helps identify the failure modes that are driven by poorly qualified staff, and hence identify the areas for additional training. In some cases it may actually eliminate the failure mode entirely, thus potentially eliminating the need for training in that area. RCM is highly supportive of TPM, because training needs can be more effectively and specifically identified and performed. The RCM process identifies the task to be performed and should always be followed by proper training to perform the task.
TPM calls for equipment management and maintenance prevention
This is inherent in RCM principles by identifying failure modes and avoiding them. Equipment is thus more effectively managed through standards for reliability at purchase (or overhaul), during storage, installation, during operation and maintenance, and in continuous cycle that feeds the design process for reliability improvement. Maintenance is prevented by doing things that increase equipment life and maximize maintenance intervals; by avoiding unnecessary PM’s through condition knowledge; and by constantly being proactive in seeking to improve reliability.
TPM calls for effective use of preventive and predictive maintenance technology
RCM methods will help identify when and how to most effectively use preventive and predictive maintenance through failure modes analysis to determine the most appropriate methods to detect onset of failure, e.g., using operators as “condition monitors,” or using a more traditional approach in predictive tools.
Performing the RCM process
One of the main benefits during the RCM process on your equipment is having the operators and maintenance in the RCM sessions. This allows both groups to communicate about the failure issues and decide as a group who best can handle the failure detection and prevention.
The most important tool in any plant is the operators that are at the machine and having the most skills at hearing, feeling, and seeing changes that may lead to equipment breakdowns and failures. Many RCM analysis sessions have some of the most valuable input from operators due to this intimate knowledge of the machine.
Many the operators will volunteer to perform the adjustments and minor lubrication tasks to keep the machine in top condition. This is also the time to develop the principles of 5S for every machine. Cleaning is part of inspecting and failure finding. Tasks can be identified around this process and captured in the RCM analysis.
One final thought is that many plants have come to think of TPM as operators doing PM and measuring OEE. Certainly that’s an essential part of it. However keep in mind that in a TPM philosophy, maintenance is about maintaining equipment function, not repairing equipment. This is a huge philosophical difference, and requires a different maintenance thought process, one which may be tough and perhaps contrary to the TPM name, is focused on eliminating defects, which result in the repair requirement.
It’s about maintenance prevention. Not preventive maintenance!