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 all we need is this one tool, apply it to everything, don’t 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 in this article 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 OEE (Overall Equipment Effectiveness) and TEEP (Total Effective Equipment Performance) calculated in terms of good product produced over key manufacturing losses (Good Product/Operational Losses+Speed Losses+Quality Losses+Planned Losses).  OEE and TEEP can easily be calculated and applied to all critical manufacturing equipment.  This measure alone will provide the engineer of how reliable each piece of manufacturing is.  The information is typically used as a benchmark to determine; is our process reliable?  Is the process more reliable this month, or last month?

Lets propose we use this measure for a more than a benchmark.  If that’s all we were looking for I would suggest you use Nakajima’s TPM calculation,  (OEE=Availability x Performance x 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 are losses are located (fig 1).  With this information, we can now begin to access where Reliability Centered Maintenance and Root Cause Analysis can best be applied to get the maximum return on the cost of the analysis investment.

Once OEE and TEEP have been calculated, the analyst can now 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 are key losses are located in the OEE and TEEP chart.   Should your process suffer 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 instead of emotions.

Reliability Centered Maintenance

Reliability Centered Maintenance 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 where the team meets from start to finish.

The RCM Process

Reliability Centered Maintenance 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 or even a declining OEE.  This will result in declining support for your RCM effort and eventually failure.

Analysis Preparation is the selection on 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 the requirements needed to start an analysis have been completed and communicated. The analysis contract is written by the facilitator and client and clearly states:

  1. The Names of RCM Analysis Team Members
  2. The Analysis Meeting Schedule and Location
  3. The Expected Outputs of the RCM Analysis
  4. Drawings, OEM’s, Existing Procedures and History Have Been Collected
  5. An Operational History Report Has Been Written Clearly Stating the Design Intent of the Process and its Present Operating Condition
  6. Assigns an Implementation Manager for the Analysis Tasks
  7. Details an Implementation Meeting Schedule
  8. Signatures of The RCM Team, Facilitator, Operations and Maintenance Managers

Completing this contract has in every case guaranteed a successful analysis.  The objective of the contract is to communicate what we are preparing to do and resources and time required to complete the RCM process. Once this has been communicated, there are no surprises, everyone involves is aware of the requirements and committed to meeting them.

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 BlitzÔ  process where a team starts 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 listed in order are:

  1. List Process Functions
  2. List the Functional Failures
  3. List the Failure Modes
  4. List the Probability 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

In performing this step of the process, also known as a Modified FMEA, the RCM facilitator should now 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 Cause Analysis.  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 now have a complete maintenance strategy for the process being analyzed.  This will include a variety of maintenance tasks including:

  1. On-Condition Maintenance Tasks (Vibration Analysis, Thermographic Analysis, Motor Current Analysis, Process Verification, Etc.)
  2. Preventive Maintenance Tasks (Schedule Rework, Scheduled Discard, Scheduled Inspection)
  3. Failure Finding Tasks
  4. Recommended Redesigns
  5. Consequence Reduction Tasks (For components where run to failure is the maintenance strategy)

These 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 an undesired condition exists.

Once the analysis has been completed and reviewed, the team will set up the implementation strategy.

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.  While the analysis itself is an education experience equaled by no other training, it takes implementing the tasks to show the real benefits.  Implementation can be broken into four steps:

  1. Prioritize the Tasks Based on Probability and Consequence
  2. Assign a Specific Person Responsible to Implement the Task
  3. Assign a Due Date the Task Should Be Implemented by
  4. Track and Report the Progress of Implementation

Once the implementation has been completed, you can expect to see results from the effort.  Some typical results from performing an RCM analysis:

  • Improved OEE and TEEP
  • Lower Maintenance Cost
  • 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 Turn Around Time
  • Reduced Speed Losses

A completed and implemented analysis can easily save millions of dollars, the key is using the tools together to maximize the benefits, OEE and TEEP to identify the process to perform Reliability Centered Maintenance, and RCM to identify where to use Root Cause Analysis.

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