UNIVERSITY OF ZIMBABWE

FACULTY OF ENGINEERING

Department of Mechanical Engineering

Name: kelvin Wasili

Reg Number: R158993X

Lecture: K Mugwindiri

Email: wasililloyd@gmail.com

Due date: 01-10-2018

Assignment 2
Part 1 [1]

(FMECA) Failure Mode, Effects and Criticality Analysis

It is defined as a methodology used to identify and analyze all potential failure modes of various
parts of a system, the effects these failures have on the system, how to avoid the failures
and /or mitigate the effects of the failures on the system [1]. In simple terms it is just defined as
a technique used to identify, prioritize and eliminate potential failures from the system, design
or process before they reach the customer [1]. Lastly but not least FMECA is a technique to
“revolve potential problems in a system before they occur”. Initially, the FMECA was called the
FMEA that is (Failure Modes and Effects Analysis) and later on a C was introduced to indicates
the criticality (or severity) of the various failure effects are considered and ranked. This method
is the most widely used reliability analysis technique in the initial stages of product /system
development usually performed during the conceptual and initial design phases of the system
in order to assure that all potential failure modes have been considered and the proper
provisions have been made t eliminate these failures.

FMECA can be used to design alternatives with high reliability and high safety potential during
the early design phases that is when design of new products is underway (FMECA) is used to
provide alternatives solutions which are more liable and provide high safety potential during
early stages of the design. It also ensures that all conceivable failure modes and their effects on
the operational success of the system have been considered. FMECA list all potential failures
and identify the severity of these effects and also develop early criteria for test planning and
requirements for test equipment [3]. A historical documentation for future reference to aid in
analysis of field failures and consideration of design chances is provided along with a bases of
maintenance planning and a bases for quantitative reliability and availability analyses [4].
FMECA is famously known for its basic seven questions which are, what are the functions and
associated performing standards of the asset, in what ways does it fail to fulfill its function,
what causes its functional failure, what could the effects be if the failure did occur, in what way
does each failure matter, what can be done to prevent each failure and what can be done if a
suitable preventive task can not be found. FMECA should be initiated early in the design
process, where we are able to have the greatest impact on the equipment reliability. Three
types of FMECA exist which are design FMECA which is carried out to eliminate failures during
equipment design, considering all types of failures during the whole life-span of the equipment
[5]. Process FMECA is focused on problems stemming from how an equipment is manufactured,
monitored maintained or operated. System FMECA looks for potential problems and
bottlenecks in larger process, such as entire production line of an automobile manufacturing
company. Two approaches to FMECA are the bottom-up approach which is used when a system
concept has been decided and each component on the lowest level of indenture is studied one
by one and all components are considered hence the analysis is complete. This approach is also
termed the hardware approach [4]. The second approach is the top down approach mainly
used in an early phase before the whole system structure is decided and the analysis is function
oriented that is it starts with main functions and how these may fail that is they prioritize
functional failures with significant effects unlike the bottom up approach the analysis is not
necessarily complete. This approach is best suited for already existing system just to focus on
problem areas.

Total Productive Maintenance (TPM)

According to total productive maintenance (TPM) is defined as a company-wide, team-based

effort to build quality into equipment and to improve productivity by reducing the time lose
due to breakdowns [6]. It is also defined as a systematic approach for understanding the
equipment’s function, the equipment’s relationship to product quality and the likely cause and
frequency of the critical equipment components. It prevents quality defects and breakdowns,
eliminate the need for equipment adjustments, and makes the work easier and safer for
equipment operators [7]. It is aimed at maximizing equipment effectiveness through the
optimization of equipment availability, performances, efficiency and product quality. Also
aimed at increasing productivity by reducing lost production time, increasing available time for
production and therefore from the process. TPM is based on eight key strategies also referred
to as pillars which are autonomous maintenance and it involve the operator in daily machine
maintenance, planned maintenance thus the maintenance activities are planned so that
production is not interrupted, equipment and process improvement which involves
identification and problem solving of recurring problems, early management of new equipment
since new equipment achieve desired performance levels earlier, quality management which is
the introduction of improving projects to address quality issues, TPM in the office which
addresses waste in administration functions, education and training develop operators so that
they can routinely maintain equipment and lastly safety and environmental management this
strategy eliminate potential safety risks, improve the working environment [8]. TPM functions
in three main areas preventive maintenance which is the continuous checking and prevention
of major maintenance by planning regular checkup. Corrective maintenance which is the
correction of problem when they occur. Maintenance prevention a process which include like
purchasing correct machinery for the job and or modifying machine to avoid maintenance [7].
The essentials of TPM are self-maintained workplace, elimination of six big losses (breakdown,
setups, minor stoppages, reduced speed, startup defects, production defects), zero breakdown,
zero defects, optimal life and availability of tools, self-improvement, short production-
development time &low machine life cost, productivity in indirect departments and zero
accidents. Benefits associated with TPM are productivity improvement through fewer losses in
the company. Quality improvement, quality is improved as a result of reductions of
equipment’s malfunctions and failures. Employee ownership, ownership of equipment by
operators through autonomous maintenance. Employee gain confidence through “zero failure”,
“zero defect” and “zero accident” conditions. Improved working environment, clean working
conditions provides a good working environment. increased plant reliability and customer
satisfactory, TPM leads to high delivery performance and customer satisfaction [9].

Part ii
To a Zimbabwe manufacturing sector TPM maintenance strategy is better as compared to
FMECA Zimbabwe as a developing countries the production sector doesn’t have enough capital
to carry out expensive researches needed in FMECA maintenance strategy for example at a
production plant with a boiler research on how the boiler fails, and effects of its failure have to
be studied that is information that describes the system has to be analyzed including drawings,
specifications, schematics, components lists, interface information and functional description
and this is costly in terms of time and money whereas TPM is characterized by involves the
operator to do basic maintenance stuff for example an operator who operates a lathe machine
will do simple maintenance like dusting, oiling and tensioning of sag cables this is cheap and
very economic instead of hiring the maintenance team. It also means that the maintenance
team will have now to focus on more critical maintenance that threatens the running time of
the plant. This also means operator ownership for maintenance and frequent cleaning of
equipment leads to earlier detections of problem for example some leakages when some one is
cleaning the machine are easily noticeable. TPM also involves planned maintenance which is
when maintenance is scheduled to reduce loss of available time and this is economic since n
time is lost through downtimes and also less chances of overtimes which are expensive and
scheduling of maintenance is based on predictive failure rates. For example, an organization
that normally operates during the day will schedule their maintenance during the night so as to
avoid down time. In TPM there is improved safety and quality performance. TPM result also in
an overall equipment and process improvement thus the improvement of the three losses
equipment losses, manpower losses and material losses. Equipment losses also known as the
big six losses breakdowns, set-up/adjustments, idling/minor losses, speed, quality defects and
startup losses. These losses are addressed through the implementation of an overall equipment
efficiency OEE. TPM also through early management of new equipment improves the design of
new equipment so that they may became easy to maintain easy to use, easy to clean and more
reliable, in all cases this reduce the loss of time through unnecessary maintenance and cleaning
that machine and more time is used in production. TPM introduces improvement projects t
address the recurring quality issues which is its major advantage over FMECA. It identifies and
resolve quality issues t decrease the cost of quality and also introduces lean initiatives such as
error proofing and root cause analysis to reduce the occurrence of defects. Increased quality
means a better fighting opportunity for organizations that are facing fierce competition from
other organization who are also in the same business line. TPM improves efficiency of the
production by reducing the issues generated in the administration tasks such as raw materials
procurement, order entry and release of orders to production. Operators are developed s they
can routinely maintain production equipment like mentioned above frees-up maintenance
personnel to concentrate proactively on improvement activities such as preventive
maintenance. Lastly but not least TPM eliminates potential safety risks and improves the
working environment and healthy workforce means more productivity. FMECA is not suitable
for multiple failures it is more applicable to those organization with one main failure for
example a plant where only one machine is a key machine which results to downtimes other
machines or failures are minor. On FMECA approach it is too easy to forget human error since it
mainly focusses on major. The FMECA approach may be tedious, time consuming [3] and
expensive and with the current situation in Zimbabwe the TPM is the most appropriate
solution. How ever the FMECA is a very structured reliable method for revaluating hardware
systems.

References

[1] O. Maurice, TPM and OEE, LBSPartners press, 2002.

[2] M. Rausand, “FMECA,” in Production and Quality Engineering, Trondheim, RAMS GROUP Press,
2014, p. 45.

[3] T. M. EL-Dogdog, “Implementation of FMECA,” International Journal of Innovative research in

engineering, vol. 5, no. 11, p. 25, 2016.

[4] S. Waghmare, “FMECA and TPM A Review,” Research in advanced engineering, vol. 1, no. 6, p. 21,
2014.

[5] R. Onofrio, “FMECA for medical advice,” ScienceDirect , vol. 3, no. 9, pp. 43-50, 2015.

[6] Military Standard, “Procedure for perfoming FMECA,” Department of deffence force, Washington
DC, 1979.

[7] D. P. Prabhakar, “CBM, TPM, RCM and RCM,” Maintenance management strategies, vol. ii, no. 10,
p. 45, 2014.

[8] I. H. Afefy, “RCM Methodology and Application,” RCM, vol. 2, no. 12, p. 48, 2010.

[9] if industy forum, “Total Productive Maintenance,” Business Excellence through inspired people, vol.
iv, no. 10, p. 28, 2014.

[10] T. W. Kim, FMECA on mechanical subsystems of diseal generatr, Yusong, 1996.