Effective Reliability-based Approach to RCM
We designed our trademark RCM methodology, RCM2™, with the optimization of your company’s assets in mind. RCM2 is one of the most effective processes to help determine and safeguard the reliability and maintainability of assets. It results in the implementation of an effective and cost-saving maintenance strategy on each of the assets of the facility.
For more than three decades, we’ve used RCM2 to help organizations decide what must be done to ensure that any physical asset, system or process continues to do whatever the team wants and needs it to do.
Here’s how RCM2 can support your organization’s reliability culture:
- Increase reliability, availability and productivity
- Optimize maintenance and avoid unnecessary costs
- Boost safety awareness and environmental integrity
- Generate better understanding of equipment behavior
- Share information across the entire organization
Hit Your Targets with RCM2
RCM2 identifies the most critical assets of a company and how best to optimize its maintenance strategies to reduce system failures. Any assets that are likely to fail or have a large consequence if they do—are considered your most critical assets.
In essence, users may expect a whole host of different things from their assets, depending on certain performance parameters, such as output, throughput, speed, range and carrying capacity. Where relevant, the RCM2 process defines what users want in terms of risk (safety and environmental integrity), quality (precision, accuracy, consistency and stability), control, comfort, containment, economy, customer service and so on.
The RCM2 process identifies the ways in which the system can fail to live up to these expectations (failed states), followed by an FMECA (failure modes, effects and criticality analysis), to identify all the events which are reasonably likely to cause each failed state.
Effective techniques are then adopted to minimize the possibility of failure and improve the reliability of the facility as a whole. The RCM2 process provides powerful rules for deciding the effectiveness of any failure management policy. It also provides precise criteria for deciding how often routine tasks should be done to better boost reliability.
Gaining a Deeper Understanding
RCM2 completely transforms the view that any organization has of its physical assets. Not only does it revolutionize views about maintenance and how it can work together with operations, but it also leads to a far broader and deeper understanding about how things work in general.
As a result, assets become more reliable because they are better maintained, plus operators are less likely to do things which cause their assets to fail. A better understanding of how systems work also means that operators are far more likely to react quickly, confidently and correctly when things do go wrong—a capability which is quite literally priceless, especially in complex, hazardous, tightly coupled facilities.
The RCM2 Process
The first step in our methodology is to define the operating context and the functions of each asset in its operating context, together with the associated desired standards of performance. The objectives of maintenance are defined by the functions and associated performance expectations of the asset under consideration. The only thing likely to stop any asset performing to the standard required by its users is some kind of failure. This suggests that maintenance achieves its objectives by adopting a suitable approach to preserve asset functions and manage failures.
Therefore, before we can apply a suitable blend of failure management tools, we need to identify what failures can occur. The RCM2 process does this at two levels:
- First, by identifying what circumstances amount to a failed state then by asking what events can cause the asset to get into a failed state.
- In the world of RCM, failed states are known as functional failures because they occur when an asset is unable to fulfill a function to a standard of performance which is acceptable to the user.
The RCM2 definition leaves room for dealing with partial failures, where the asset still functions but at an unacceptable level of performance (including situations where the asset cannot sustain acceptable levels of quality or accuracy). Clearly, these can only be identified after the functions and performance standards of the asset have been defined.
Once this happens, the next step is to try to identify all the events, which are reasonably likely to cause each failed state (or failure modes). “Reasonably likely” failure modes include those which have occurred on the same or similar equipment operating in the same context, failures which are currently being prevented by existing maintenance regimes, and failures which have not happened yet but which are considered to be real possibilities in the context in question.
Most traditional lists of failure modes incorporate failures caused by deterioration or normal wear and tear. However, the list should also include failures caused by human errors (on the part of operators and maintainers), random events and design flaws so that all reasonably likely causes of equipment failure can be identified and dealt with appropriately.
It is also important to identify the cause of each failure in enough detail to ensure that time and effort are not wasted trying to treat symptoms instead of causes. On the other hand, it is equally important to ensure that time is not wasted on the analysis itself by going into too much detail. In identifying failure effects, the Facilitator should include all the information needed to support the evaluation of the consequences of the failure, such as:
- When is the failure most likely to occur (under what conditions)
- What evidence (if any) that the failure has occurred
- In what ways (if any) it poses a threat to safety or the environment
- In what ways (if any) it affects production or operations
- What physical damage (if any) is caused by the failure
- What must be done to repair the failure
- What is the revenue loss
The process of identifying functions, functional failures, failure modes and failure effects yields surprising and often very exciting opportunities for improving performance and safety, and also for eliminating waste in the maintenance process.
A detailed analysis of an average industrial undertaking is likely to yield roughly three thousand to ten thousand possible failure modes. Each of these failures affects the organization in some way, but in each case, the effects are different. They may impact operations. They may also impact product quality, customer service, safety or the environment.
They will all take time and cost money to repair. These consequences most strongly influence the extent to which we try to prevent each failure. In other words, if a failure has serious consequences, we are likely to go to great lengths to try to avoid it. On the other hand, if it has little or no effect, then we may decide to do no routine maintenance beyond basic cleaning and lubrication.
Strength of RCM2
One of the greatest strengths of RCM2 is that it recognizes that the consequences of failures are far more important than their technical characteristics. In fact, it recognizes that the only reason for doing any kind of proactive maintenance is not to avoid failures per se, but to avoid or at least to reduce the consequences of failure.
The RCM2 process classifies these consequences into four groups:
- Hidden failure consequences: Hidden failures have no direct impact, but they expose the organization to multiple failures with serious, often catastrophic, consequences. (Most of these failures are associated with protective devices, which are not fail-safe.)
- Safety and environmental consequences: A failure has safety consequences if it could hurt or kill someone. It has environmental consequences if it could lead to a breach of any corporate, regional, national or international environmental standard.
- Operational consequences: A failure has operational consequences if it affects production (output, product quality, customer service or operating costs in addition to the direct cost of repair)
- Non-operational consequences: Evident failures, which fall into this category, affect neither safety nor production, so they involve only the direct cost of repair.
The RCM2 process uses these categories as the basis of a strategic framework for maintenance decision-making. By forcing a structured review of the consequences of each failure mode in terms of the above categories, it integrates the operational, environmental and safety objectives of the maintenance function. This helps to bring safety and the environment into the mainstream of maintenance management.
If there’s one idea the consequence evaluation process cancels out from the outset, it’s the idea that all failures are bad and must be prevented. In doing so, it focuses attention on the maintenance activities, which have the most effect on the performance of the organization, and diverts energy away from those that have little or no effect.
It also encourages us to think more broadly about different ways of managing failure, rather than to concentrate only on failure prevention. Failure management techniques are divided into two categories:
- Proactive tasks: these are tasks undertaken before a failure occurs, in order to prevent the item from getting into a failed state. They embrace what is traditionally known as ‘predictive’ and ‘preventive’ maintenance, although we will see later that RCM uses the terms scheduled restoration, scheduled discard and on-condition maintenance
- Default actions: these deal with the failed state, and are chosen when it is not possible to identify an effective proactive task; Default actions include failure-finding, one-time changes and run-to-failure
The users of the assets are usually in the best position by far to know exactly what contribution each asset makes to the physical and financial wellbeing of the organization as a whole, so it is essential that they are involved in the RCM2 process from the outset.
Done properly, this step usually takes up about a third of the time involved in an RCM2 analysis. It also usually causes the team doing the analysis to learn a remarkable amount about how the equipment actually works.
To gain a better understanding of how RCM2 works, consider attending one of the RCM2 Training courses offered by The Aladon Network. Click here to see what courses are available.