Reliability Centered Maintenance (RCM)

Transcription

1 An Allied Reliability Group White Paper 4200 Faber Place Drive Charleston, SC Reliability Centered Maintenance (RCM) By: Douglas J. Plucknette, Principal July 14, 2014 Reliability it s in our DNA.

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3 Contents Introduction... 1 The Benefit of Reliability Measures... 1 Reliability Centered Maintenance... 2 The RCM Process... 2 Analysis Preparation Work... 4 Analysis... 4 Analysis Implementation... 5 Results... 5 Introduction As I attend various reliability conferences year after year, I have noted that each conference will address the topics of Root Cause Analysis, Reliability Centered Maintenance, and Reliability Measures as separate and distinct topics. Some of the presenters at these conferences will even lead us to believe that all we need is this one tool, apply it to everything, do not try to prioritize because you will miss something, and all of your problems will be solved. Looking at each tool on its own, they are separate tools each having its own benefits, but the idea that one tool will cure all of your reliability issues is insane. RCM could be applied to every piece of equipment in your plant, but at what cost? Each tool will help to advance your reliability efforts and increase your understanding of how to achieve reliability in manufacturing. What I would like to discuss is how we should use these tools together to maximize the potential of our reliability effort. The Benefit of Reliability Measures There are several Reliability Measures and calculations for each that are available for the Reliability Engineer to use. My personal favorites are Overall Equipment Effectiveness (OEE) and Total Effective Equipment Performance (TEEP) calculated in terms of good product produced over key manufacturing losses: Good Product Operational Losses + Speed Losses +Quality Losses + Planned Losses 2014 Allied Reliability Group Page 1

4 OEE and TEEP can easily be calculated and applied to all critical manufacturing equipment. This measure alone will provide the engineer with how reliable each piece of manufacturing is. The information is typically used as a benchmark to determine whether our process reliable. Is the process more reliable this month or last month? Let s propose that we use this measure for more than a benchmark. If that was all we were looking for, I would suggest you use Nakajima s TPM calculation: OEE = Availability Performance Quality This measure provides the benchmark number without clear indication of where the losses are located. By measuring and charting OEE and TEEP in terms of good product over key manufacturing losses, we provide ourselves with a clear picture of where our losses are located, as shown in Figure 1. With this information, we can now begin to assess where Reliability Centered Maintenance and Root Cause Analysis can best be applied to achieve the maximum return on the cost of the analysis investment. Once OEE and TEEP have been calculated, the analyst can then begin to look closer at each process or piece of equipment. We can now determine which process is a good candidate for an RCM analysis by looking at where our key losses are located in the OEE and TEEP chart. If your process suffers from Operational or Speed Losses that are equipment related, this process should be a candidate for an analysis. This puts the reliability measure to work for you, allowing the Reliability Engineer to base decisions on where to use Reliability Tools on real data rather than emotions. Reliability Centered Maintenance Reliability Centered Maintenance, or RCM as it is commonly known, is a reliability tool whose intent is to develop a complete maintenance strategy for a process or piece of equipment. While an RCM analysis can be performed on any process or piece of equipment, the analysis process and implementation is an undertaking that should be aimed where the return on this investment is most profitable. An RCM analysis requires a trained facilitator and a cross-functional team of three to five process experts. The team should consist of mechanics, technicians, and operators. The typical analysis of 120 to 160 failure modes will take an experienced team one week, or forty hours, to accomplish using a blitz format. The RCM Process RCM is a structured process that requires experience and discipline to complete. The total process is best viewed in three sections: 1. Analysis preparation work 2. Analysis 3. Analysis implementation Each section requires dedicated time and resources in order for the entire process to function. Without the proper preparation work, the analysis team will stall, resulting in frustration and, eventually, failure. Without analysis implementation, there will be no change in how you perform maintenance and no change in, or even a declining, OEE. This will result in declining support for your RCM effort and, eventually, failure. Page 2 Reliability Centered Maintenance

5 Figure 1: OEE/TEEP in Terms of Good Product Manufactured and Key Manufacturing Losses 2014 Allied Reliability Group Page 3

6 Analysis Preparation Work Analysis Preparation is the selection of a process, the forming and training of an analysis team, and the gathering of information needed to perform a thorough analysis. This step was skipped so often by facilitators I trained that I now require them to show me a signed contract between the facilitator and the client that clearly shows that the requirements needed to begin an analysis have been completed and communicated. The analysis contract is written together by the facilitator and client and should include: The names of RCM Analysis Team Members; The analysis meeting schedule and location; The expected outputs of the RCM analysis; The Implementation Manager for the analysis tasks; The details of the Implementation Meeting Schedule; Signatures of the RCM Team, Facilitator, and Operations and Maintenance Managers. Drawings, OEM manuals, existing procedures, and an Operational History Report should also be collected and included with the contract. The Operational History Report should clearly state the design intent of the process and its present operating condition. Completing this contract has, in every case I have been involved with, guaranteed a successful analysis. The objective of the contract is to communicate what we are preparing to do and the resources and time required to complete the RCM process. Once this has been communicated, there are no surprises; everyone involved is aware of the requirements and committed to meeting them. Analysis The RCM Analysis is the second step in the RCM process. It again requires structure and discipline. The analysis is best completed by using the RCM Blitz process, where a team begins the analysis and meets each day until the analysis has been completed. This process helps the team stay focused on the process and eliminates the continuous time-wasting review that results from a fractured meeting schedule. An RCM analysis requires the team to complete nine critical steps in order to develop a complete maintenance strategy for the process or piece of equipment being analyzed. The nine steps, in order, are: 1. List process functions. 2. List the functional failures. 3. List the failure modes. 4. List the probability that each failure will occur. 5. List the effects of the failure. 6. List the consequences of the failure. 7. Run the failure mode through the RCM Decision Process. 8. Develop a Maintenance Task, Redesign, or Consequence Reduction Task. 9. Run the failed part through the RCM Spare Parts Decision Process. This step of the process is also known as a modified Failure Mode and Effects Analysis (FMEA). The RCM Facilitator should note components that the team designated as having a high probability failure rate and a medium to high consequence rating. These components are classic candidates for Root Page 4 Reliability Centered Maintenance

7 Cause Analysis (RCA). RCA will focus the team on all of the possible failures of this component, including physical, human, and latent failures. Once these nine steps have been completed, the team will have a complete maintenance strategy for the process being analyzed. This will include a variety of maintenance tasks: On-Condition Maintenance Tasks (Vibration Analysis, Thermographic Analysis, Motor Circuit Analysis, Process Verification, etc.) Preventive Maintenance Tasks (Scheduled Rework, Scheduled Discard, Scheduled Inspection) Failure Finding Tasks Recommended Redesigns Consequence Reduction Tasks (for components where run-to-failure is the maintenance strategy) The procedures that accompany these tasks should be clearly written and specific in content, clearly stating what the person performing the task should observe, measure, record, and do in the event that an undesired condition exists. Once the analysis has been completed and reviewed, the team will set up the implementation strategy. Analysis Implementation Implementing the RCM analysis is the last step in the RCM process. If not completed, your team has wasted its time, and your company has wasted its money. Implementation can be broken into four steps: 1. Prioritize the tasks based on probability and consequence. 2. Assign a specific person responsible for implementing the task. 3. Assign a due date for when the task should be implemented by. 4. Track and report the progress of implementation. Results Once the implementation has been completed, you can expect to see results from the effort. Some typical results from performing an RCM analysis are: Improved OEE and TEEP Lower maintenance costs Lower unit cost of product Reduction in health, safety, and environmental incidents Improved quality Reduced emergency maintenance Reduced spare parts Reduced set up times Reduced turnaround time Reduced speed losses A completed and implemented analysis can easily save millions of dollars. The key is using the reliability tools together to maximize the benefits: OEE and TEEP to identify the process on which to perform RCM and RCM to identify where to use RCA. While the analysis itself is an education experience equaled by no other training, it takes implementing the tasks to show the real benefits Allied Reliability Group Page 5

8 About Allied Reliability Group Allied Reliability Group (ARG) offers best-inindustry maintenance, reliability, and operational consulting and services, training, staffing, and integrated software solutions servicing the industrial and manufacturing sector. Reliability it's in our DNA. For more information about Allied Reliability Group, please contact: Global Headquarters Allied Reliability Group Reliability Centered Maintenance