An overview of RCM and FMEA

RCM and FMEA 1
RCM and FMEA
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RCM and FMEA 2
Question 1: Reflective essay
An overview of RCM methodology
Reliability centered maintenance can be defined as a process that is designed to systematically
analyze an engineered system with the aim to determine characteristics of the system such as (Peter,
2015):
i) The requirements for spare holding
ii) The failure modes for equipment and the causes of functional failures.
iii) The impact functional failure has on the system functions
iv) The best strategy for managing potential failures. This includes carrying out maintenance
tasks aimed at preventing failures from occurring or even detecting potential failures
before they happen
The major objective of reliability centered maintenance is to achieve system reliability in all its modes
of operation (Blokdyk, 2019). RCM has been widely applied in many different industries ranging from
the aviation industry to electrical utility and process industries for a long time with significant success
(Blokdyk, 2019). System maintenance can be applied and evaluated in a rational manner through the
application of RCM principles. This offers the greatest value to the system operator or owner. RCM
maintenance program enables the effective management of the risk losses that may arise from
equipment failure hence it forms a part of the overall risk management (Duffuaa & Raouf, 2015). To
achieve this failure management, maintenance resources are allocated to equipment maintenance
depending on the risk impact on the equipment or system (Amadi-Echendu, Brown, Willett, & Mathew,
2010).
Expertise in the following areas is necessary in order to successfully carry out an RCM analysis
on a system: familiarity with condition monitoring methods, design, engineering and operational
knowledge of the system including other maintenance practices (proactive) such as lubrication (Ren,
2016). In addition, analytical tools such as failure mode and effects analysis (FMEA) and RCM task
selection flow charts are valuable. With these tools and the outlined expertise, RCM analysis can
establish the relationship between system performance and equipment failure (Jasiulewicz-
Kaczmarek, 2014). To develop an RCM program, the following steps are followed in general
(Campbell, Jardine, & McGlynn, 2016):
i) Firstly, the major components of the system are listed as well as their definitions and
functions
ii) The failure modes likely to develop are identified for every major component
iii) Considering the failure history of the components, the severity of the failure modes is then
assigned a corresponding risk priority number (Jasiulewicz-Kaczmarek, 2014).
iv) The next step involves determining the preventive maintenance tasks for each failure
mode
v) From the above information, an RCM process is designed for the desired system
vi) Finally, the developed RCM program is evaluated to determine its effectiveness and
worth.
Advantages of RCM
i) RCM helps prevent or minimize damage to property or human injury. It can also minimize
environmental pollution such as pollution due to spillage (Singh, 2017).
ii) It significantly reduces the costs associated with maintenance and repair of equipment
due to the emphasis placed on improving the reliability of equipment
iii) A piece of equipment is only replaced based on its actual condition hence the maximum
equipment utilization is achieved (McMillan & Ault, 2014).
Disadvantages of RCM
i) The initial cost of RCM endorsement is usually high due to the purchase of necessary
technological apparatus (Anderson & Neri, 2012).
ii) Its ability to save costs is not readily seen by the management
iii) The large number of industrial equipment makes it cumbersome to select the best
maintenance strategy for every component.

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An overview of the FMEA process
Failure mode and effects analysis (FMEA) also referred to as failure modes, effects, and criticality
analysis (FMECA) can be defined as a procedure that is used to systematically identify, analyze, and
document potential system or product failures (Stamatis, 2014). It is a method designed to (Wilson,
2012):
i) Pinpoint potential system failure modes, their causes as well as the effects the failures
have on the system, its components or users
ii) Analyze and understand the risks related to the identified failure modes and suggest
possible corrective actions depending on the priority and severity of the failures
iii) Suggest and carry out corrective procedures to tackle the major concerns arising from the
failure modes
FMEA is usually a directive towards the development of a set of procedures that mitigate the risks
associated with a system or its components to levels acceptable to work with (Stamatis, 2019).
Primarily, FMEA is intended to improve the design of a system in the following aspects: in the case of
system FMEAs, the goal is to improve the system design. In the case of Design FMEAs, the goal is to
improve subsystem or component design. Finally, in the case of process FMEAs, the goal is to
improve manufacturing process design (Carlson, 2012). Secondary objectives of FMEAs include the
identification and prevention of safety hazards, minimization of the degradation of product
performance, development of techniques for online diagnostics, improvement of verification and test
plans, development of preventive maintenance plans for equipment and machinery in service and the
identification of process or product characteristics (Failure Mode Effects and Criticality Analysis
(FMECA), 2012).
FMEA comprises of three main elements namely (Carnero & González-Prida, 2016):
i) Failure mode: this specifies the method in which a system fails to perform according to its
specifications or its intended function
ii) Effect: this refers to the impact the failure mode has on the component, process or
customer
iii) Cause(s): this describes the means through which the component or equipment resulted
in failure
An FMEA analysis can be performed via the following nine steps (Gómez et al, 2017):
Step 1
Identification of the system components and their functions
Step 2
Identification of the failure modes associated with each component
Step 3
Identification of the effects of the failure modes
Step 4
Determination of the severity of the failure modes
Step 5
Identification of the failure causes
Step 6
Determination of the probabilities of occurrence
Step 7
Identification of controls and the determination of their effectiveness
Step 8

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Calculation of risk priority numbers
Step 9
Determination of actions to mitigate failure mode risks
Benefits of FMEA analysis
i) It enables the designer to take actions to mitigate failure depending on risk priority
numbers (Minnaard, 2013).
ii) It is useful in identifying the parts of a system whose failure greatly impacts customers
iii) It enables a designer to identify the major system components whose design should be
given special attention during design
Drawbacks of FMEA analysis
i) In some instances, the use of FMEA does not affect the design or the decision-making
process as it is applied much later (Sarno Severi, 2014).
ii) It can be time-consuming to trace component failure via FMEA tables and charts
iii) It does not take into account the relationships between system components
Question 2: Article review
EVALUATING A RELIABILITY CENTERED MAINTENANCE PROGRAM FOR SUBSTATION
EQUIPMENT AT NEW CENTURY ENERGIES
Introduction
The aim of this article was to investigate the application of reliability centered maintenance on
direct current (DC) power supply at a power substation. The choice of DC power supplies was based
on their relative simplicity and their significantly associated low cost of RCM analysis. Despite their
simplistic nature, DC equipment is very crucial in every substation as they are required to provide the
necessary power for the operation of protective equipment such as circuit breakers.
Summary of the article
Scope of the substation DC power supply
According to Wilmeth & Usrey (2010), the direct current power supply equipment at a
substation consists of storage batteries and battery chargers. The function of the battery charger is to
power the direct current operated equipment and to keep the battery fully charged during normal
operation. In the case of battery charger failure or interruption of the alternating current (AC) supply,
the battery steps in and provides an emergency DC supply to the station equipment for its continued
operation. For this study, Wilmeth & Usrey (2010), considered the DC power supply as a system due
to the fact that it is made up of two separate pieces of equipment (the battery and battery charger). As
a result, instead of carrying out two distinct studies on the battery charger and the battery. Wilmeth &
Usrey (2010) grouped the components in order to perform a system study. The authors performed a
system analysis on the DC power supply aimed at establishing its operation, design and the actual
maintenance actions necessary.
System boundary and interfaces
According to (2010), it is important to define a system boundary in order to set the limits of the
reliability centered maintenance study. The system's physical boundaries were identified as the
battery charger, the battery and the interconnection between them consisting of cables. In addition to
the system boundaries, interfaces are necessary to support the system or equipment operation. An
interface is defined as an item that is external to the system boundary (Wilmeth & Usrey, 2010). The
authors identified the following interfaces for the DC supply system:
i) Cable connections to the DC bus
ii) AC to DC converter for the battery charger
iii) The grounding connection on the battery charger for operator and equipment safety

RCM and FMEA 5
iv) Remotely controlled SCADA alarm system
Results and analysis
Dominant failure modes
Dominant failure modes define the likely manner in which an equipment is to fail (Wilmeth & Usrey,
2010). During the system’s equipment analysis, the authors identified the following dominant failure
modes:
i) Breaking of the battery conduction path
() identified the failure effects associated with this failure mode. These include the inability of the
circuit breakers controlled by the DC source to trip in case of fault development. Another effect
includes the probable employee or public safety compromise and the prospective damage to
expensive station protective gear. They further identified this as a critical failure mode.
ii) Low battery capacity
The identified failure effects corresponding to this failure mode include a shortened duration for the
battery to support its intended load and the inability of circuit breakers to trip in case of fault
development (Wilmeth & Usrey, 2010). Wilmeth & Usrey (2010) identified this failure mode as critical.
iii) No output from the battery charger
If the alternating current adapter that supplies energy to the battery fails, the storage will supply its
stored energy up to exhaustion after which the circuit breakers will not be able to function without the
necessary supply. Wilmeth & Usrey (2010) identified this failure mode as critical too.
iv) Alarm failure
According to Wilmeth & Usrey (2010), one of the important functions of the alarm is to provide a
warning if the storage battery is running low. As a result, the failure of the alarm system makes it
impossible to keep track of battery level and condition. This failure mode was also assigned a critical
value.
Dominant failure causes
According to Wilmeth & Usrey (2010), a dominant failure cause gives the reason why the
failure mode occurs. To determine the appropriate maintenance resources and to develop effective
strategies to avoid the failure mode, the cause of the failure must be fully understood. For instance,
the dominant failure causes leading to the break of battery conduction path include: loose connection
with a recommended task of condition monitoring, corrosion of the conduction path with a
recommended RCM task of cleaning corroded connections and grounding issues with a
recommended time directed task of measuring the voltage between the positive and negative
terminals of the battery to ground.
Task comparison
After carrying out RCM analysis and recommendations, it is necessary to compare the tasks
recommended by RCM, the prevalent maintenance tasks, and regulatory requirements. Wilmeth &
Usrey (2010) established that, if the recommended maintenance actions were adopted, it would be
possible to have savings equivalent to 3 man-hours per annum. Despite the fact that these savings
sound quite low, they become quite significant when the strategy is applied across the DC power
supply equipment in other substations.
Conclusions of the RCM study
Wilmeth & Usrey (2000) found that the DC power supply components at the stations were
being neglected in terms of maintenance while others were being overly maintained. They established
that for the maximum savings to be realized, the RCM studies and the recommended strategies would
have to be duplicated across the entire population of substations. The study also showed that many

RCM and FMEA 6
substation inspections were being performed on a monthly basis with assorted equipment other than
the DC power supplies being checked. They, therefore, concluded that it was necessary to automate
some more functions in the future which would cut the number of substation inspections carried out
each month. Previously, research had indicated that with the use of battery alarms, it would be
possible to reduce the inspections of DC power supplies from 12 to only 4 per year. Besides, the time
amount necessary to inspect a single station would be significantly reduced.
Question 3
My team was able to isolate the following dominant failure modes after the FMEA analysis of the
flashlight problem.
i) Flashlight unable to produce any light
This is a case in which the flashlight is completely unable to perform its intended function (to
produce light). This renders the flashlight completely useless and cannot be tolerated. Consequently,
the team assigned this failure mode the highest ranking in severity which is 4. Since it is quite easy to
recognize a flashlight in the off state, the detectability was awarded the highest number, 4.
Failure causes
Several causes for this failure mode were identified. One of these causes was identified as the
possible incorrect insertion of the flashlight batteries. For instance, the batteries may be inserted with
their similar polarities in contact (positive to positive or negative to negative). This would completely
break the electrical conduction path and no current would flow through the bulb and the flashlight
would remain in the off state. Another possible cause for this failure mode was identified as the result
of the slide switch being stuck while in the off position. This, in turn, could be the corrosion of the
switch contacts due to old age or to exposure to humid conditions constantly. The team decided that
these causes rarely happen and thus the probability of failure was assigned the lowest available
number. The recommended action is to clean any corroded contacts or replace them if possible.
ii) Flashlight working intermittently
This is a case in which the flashlight does part of its job unsatisfactorily. The bulb sometimes
grows bright while getting dim sometimes. In some cases, the bulb even goes off completely for some
time but resumes operation, for example when shaken.
Causes of this failure mode
My team identified one of the potential causes for this failure mode as loose contact between the
flashlight housing spring and the rear battery. It could also occur as a result of loose contact between
the bulb housing spring and the bulb. This, in turn, could be due to the weakening of the spring due to
old age. Another possible cause for this failure mode was identified as the corrosion of the flashlight
contacts such as the spring and the slide switch contact. A moderate severity was given to this failure
mode. The probability was given a low value as this usually happens as the flashlight gets older. The
detectability was assigned a high number. The recommended action is to clean the flashlight contacts
using a solution of vinegar.
iii) The flashlight produces continuous illumination (never goes off)
This is a case where the flashlight produces a continuous light and never goes off except for
instance if the batteries are removed. Like in the first case, this failure mode is also unacceptable and
the severity has the highest number. The probability was assigned a low number while the
detectability was given the highest available numeral.
Failure causes
The main failure cause for this mode was identified as a result of the slide switch getting stuck
while in the on-state. This, in turn, could be due to the corrosion of the switch contacts. The team
recommended replacing the switch as the best action in this case.

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References
Amadi-Echendu, J. E., Brown, K., Willett, R., & Mathew, J. (2010). Definitions, Concepts and Scope
of Engineering Asset Management. Berlin, Germany: Springer Science & Business Media.
Anderson, R., & Neri, L. (2012). Reliability-Centered Maintenance: Management and Engineering
Methods. Berlin, Germany: Springer Science & Business Media.
Blokdyk, G. (2019). FMEA Failure Modes Effects Analysis A Complete Guide - 2019 Edition.
5starcooks.
Campbell, J. D., Jardine, A. K., & McGlynn, J. (2016). Asset Management Excellence: Optimizing
Equipment Life-Cycle Decisions, Second Edition. Boca Raton, FL: CRC Press.
Carnero, M., & González-Prida, V. (2016). Optimum Decision Making in Asset Management.
Hershey, PA: IGI Global.
Carlson, C. (2012). Effective FMEAs: Achieving Safe, Reliable, and Economical Products and
Processes using Failure Mode and Effects Analysis. John Wiley & Sons.
Duffuaa, S. O., & Raouf, A. (2015). Planning and Control of Maintenance Systems: Modelling and
Analysis. Springer.
Failure Mode Effects and Criticality Analysis (FMECA). (2012). Effective FMEAs, 285-296.
doi:10.1002/9781118312575.ch12
Gómez Fernández, J. F., Ferrero Bermejo, J., Olivencia Polo, F. A., Crespo Márquez, A., & Cerruela
García, G. (2017). Dynamic Reliability Prediction of Asset Failure Modes. Advanced
Maintenance Modelling for Asset Management, 291-309. doi:10.1007/978-3-319-58045-6_12
Jasiulewicz-Kaczmarek, M. (2014). Practical aspects of the application of RCM to select optimal
maintenance policy of the production line. Safety and Reliability: Methodology and
Applications, 1187-1195. doi:10.1201/b17399-165
McMillan, D., & Ault, G. W. (2014). Towards Reliability Centred Maintenance of Wind
Turbines. Reliability Modeling and Analysis of Smart Power Systems, 183-194.
doi:10.1007/978-81-322-1798-5_12
Minnaard, H. (2013). Asset Reliability & Integrity Management for delivering asset value. IET & IAM
Asset Management Conference 2013. doi:10.1049/cp.2013.1935
Peter, R. W. (2015). Defining Maintenance Strategies for Critical Equipment With Reliability-Centered
Maintenance (RCM). Reliable Maintenance Planning, Estimating, and Scheduling, 145-155.
doi:10.1016/b978-0-12-397042-8.00009-7
Ren, D. (2016). Reliability centered maintenance for condition based maintenance application on
transformation equipment. Electronics, Electrical Engineering and Information Science.
doi:10.1142/9789814740135_0011
Sarno Severi, E. (2014). Reliability improvement programs and asset management optimization for
the asset intensive industries. Asset Management Conference 2014.
doi:10.1049/cp.2014.1050
Singh, R. (2017). Asset Integrity Management and Other Concepts of Asset Reliability. Pipeline
Integrity Handbook, 271-288. doi:10.1016/b978-0-12-813045-2.00018-1
Stamatis, D. (2014). The ASQ Pocket Guide to Failure Mode and Effect Analysis (FMEA). ASQ
Quality Press.
Stamatis, D. (2019). Risk Management Using Failure Mode and Effect Analysis (FMEA). ASQ Quality
Press.
Wilmeth, R. G., & Usrey, M. W. (2000). Reliability-centered maintenance: A case study. Engineering
Management Journal, 12(4), 25-31.
Wilson, A. (2012). Asset Maintenance Management: A Guide to Developing Strategy & Improving
Performance. Industrial Press.