Reliability engineering is concerned with ensuring systems and components function as intended for a specified period of time. It involves tasks like requirements specification, design, testing, and maintenance to analyze and improve reliability. A reliability engineer identifies potential failure modes and assesses risks to reduce costs from downtime and repairs. Key responsibilities include advising on new installation designs, participating in risk management, and developing engineering solutions to recurring problems. Reliability engineering differs from safety engineering in considering a broader set of hazards focused on costs rather than severe accidents.

2. Outline
• Reliability Definition
• Engineering Definition
• Reliability Engineering Definition
• Reliability Engineering versus Safety Engineering
• Roles of a Reliability Engineer
• Terotechnology

3. Reliability Definition
It is theoretically defined as
the probability of failure, the
frequency of failures, or in
terms of availability, a
probability derived from
reliability and maintainability.

5.  The idea that an item is fit for a purpose with respect to time.
 The capacity of a designed, produced or maintained item to
perform as required over time
 The capacity of a population of designed, produced or
maintained items to perform as required over specified time
 The resistance to failure of an item over time
 The probability of an item to perform a
required function under stated conditions for
a specified period of time
 The durability of an object.
Reliability Definition

6. "Reliability is, after all,
engineering in its most
practical form.”
-James R. Schlesinger
Former US Secretary of Defence

7. Engineering
• is the application of scientific,
economic, social, and practical
knowledge in order to design, build,
and maintain structures, machines,
devices, systems, materials and
processes. It may encompass using
insights to conceive, model and scale
an appropriate solution to a problem
or objective.

8. Reliability Engineering
• is an engineering field that deals
with the study, evaluation, and life-
cycle management of reliability:
the ability of a system or
component to perform its
required/intended functions under
stated conditions for a specified
period of time.

9. Reliability Engineering
• Reliability engineering is a sub-discipline
within Systems Engineering.
• Reliability engineering may involve the
creation of proper use studies and
requirements specification, hardware &
software design, functional (failure)
analysis, testing and analyzing
manufacturing, maintenance, transport,
storage, spare parts stocking, operations
research, human factors and technical
documentation.

10. Many engineering techniques are used in reliability engineering,
such as Reliability Hazard analysis, Failure mode and effects analysis
(FMEA), Fault tree analysis (FTA), Material Stress and Wear calculations,
Fatigue and Creep analysis, Finite Element Analysis, Reliability Prediction,
Thermal (Stress) analysis, Corrosion Analysis, Human error analysis,
Reliability testing, Statistical uncertainty estimations, Monte Carlo
simulations, Design of Experiments, Reliability Centered Maintenance
(RCM), Failure Reporting and Corrective Actions management.
Because of the large number of reliability
techniques, their expense, and the varying degrees of
reliability required for different situations, most
projects develop a reliability program plan to specify
the reliability tasks that will be performed for that
specific system.

11. Consistent with the creation of safety cases, for
example ARP4761, the goal is to provide a
robust set of qualitative and quantitative
evidence that use of a component or system will
not be associated with unacceptable risk.
ARP4761, Guidelines and Methods for Conducting
the Safety Assessment Process on Civil Airborne
Systems and Equipment is a standard (actually a
Recommended Practice) from the Society of
Automotive Engineers

12. The basic steps to take are to:
1. First thoroughly identify relevant unreliability "hazards", e.g.
potential conditions, events, human errors, failure modes,
interactions, failure mechanisms and root causes, by specific
analysis or tests.
2. Assess the associated system risk, by specific analysis or testing.
3. Propose mitigation, e.g. requirements, design changes,
detection, maintenance, training, by which the risks may be
lowered and controlled for at an acceptable level.
4. Determine the best mitigation and get agreement
on final, acceptable risk levels, possibly based
on cost-benefit analysis

13. • Risk is the combination of probability and severity of the
failure incident (scenario) occurring.
• Severity of failures include the cost of spare parts, man
hours, logistics, damage (secondary failures) and
downtime of machines which may cause production loss.
• What is acceptable is determined by the managing
authority or customers.
• Residual risk is the risk that is left over after all reliability
activities have finished and includes the
un-identified risk and is therefore
not completely quantifiable.

14. Reliability engineering
vs
Safety Engineering

15. Reliability engineering differs from safety engineering
with respect to the kind of hazards that are considered.
Reliability engineering is in the end only concerned with
cost. It relates to all Reliability hazards that could transform
into incidents with a particular level of loss of revenue for
the company or the customer. These can be cost due to
loss of production due to system unavailability, unexpected
high or low demands for spares, repair costs, man hours,
(multiple) re-designs, interruptions on normal
production (e.g. due to high repair times
or due to unexpected demands for non-stocked
spares) and many other indirect costs.

16. Safety engineering, on the other hand, is more specific and
regulated. It relates to only very specific and system Safety
Hazards that could potentially lead to severe accidents. The
related functional reliability requirements are sometimes
extremely high. It deals with unwanted dangerous events (for
life and environment) in the same sense as reliability
engineering, but does normally not directly look at cost and is
not concerned with repair actions after failure / accidents (on
system level). Another difference is the level of impact of
failures on society and the control of
governments. Safety engineering is often strictly
controlled by governments (e.g. Nuclear,
Aerospace, Defense, Rail and Oil industries).

17. What is the role of
a reliability
engineer?

18. Reliability Engineer
The primary role of the reliability
engineer is to identify and manage
asset reliability risks that could
adversely affect plant or business
operations. This broad primary role can
be divided into three smaller, more
manageable roles: loss elimination, risk
management and life cycle asset
management (LCAM).

19. Loss Elimination
One of the fundamental
roles of the reliability
engineer is to track the
production losses and
abnormally high maintenance
cost assets, then find ways to
reduce those losses or high
costs.

20. Risk Management
Another role of the reliability
engineer is to manage risk to
the achievement of an
organization’s strategic
objectives in the areas of
environmental health and
safety, asset capability, quality
and production.

21. Some tools used by a reliability engineer
to identify and reduce risk include:
• PHA – Preliminary hazards analysis
• FMEA – Failure modes and effects analysis
• CA – Criticality analysis
• SFMEA – Simplified failure modes and effects
analysis
• MI – Maintainability information
• FTA – Fault tree analysis
• ETA – Event tree analysis

22. Life Cycle Asset
Management
Studies show that as much as 95 % of
the Total Cost of Ownership (TCO) or
Life Cycle Cost (LCC) of an asset is
determined before it is put into use.
This reveals the need for the reliability
engineer to be involved in the design
and installation stages of projects for
new assets and modification of
existing assets.

24. 1. Works with project engineering to ensure the reliability and maintainability of new
and modified installations. The reliability engineer is responsible for adhering to the
life cycle asset management (LCAM) process throughout the entire life cycle of new
assets.
2. Participates in the development of design and installation specifications along with
commissioning plans. Participates in the development of criteria for and evaluation
of equipment and technical maintenance service providers. Develops acceptance
tests and inspection criteria.
3. Participates in the final check-out of new installations. This includes factory and site
acceptance testing that will assure adherence to functional specifications.
4. Guides efforts to ensure reliability and maintainability of equipment,
processes, utilities, facilities, controls and safety/security systems.
5. Provides input to a risk management plan that will anticipate
reliability-related and non-reliability-related risks that could
adversely impact plant operations.
Here’s a list of responsibilities and duties commonly
found in the job description of a reliability engineer:

25. 6. Develops engineering solutions to repetitive failures and all other
problems that adversely affect plant operations. These problems include
capacity, quality, cost or regulatory compliance issues.
7. Works with Production to perform analyses of assets including:
a. Asset utilization
b. Overall equipment effectiveness
c. Remaining useful life
d. Other parameters that define operating condition, reliability and costs
of assets
8. Provides technical support to production, maintenance
management and technical personnel
9. Applies value analysis to repair/replace, repair/redesign
and make/buy decisions.
Continuation...

27. Terotechnology
The technology of installation,
commissioning, maintenance, replacement
and removal of plant machinery and
equipment, of feed-back to operation and
design thereof, and to related subjects and
practices.
A branch of “Maintenance
Engineering & Technology”

28. Terotechnology
Greek Word Tero = “I care”
+ Technology
– Refer to the study of the costs associated with an
asset throughout its life cycle – from acquisition to
disposal.
– The goals of this approach are to reduce the
different costs incurred at the various
stages of the asset’s life and to develop
methods that will help extend the asset’s
life span.

29. It is the maintenance of assets in
optimal manner. It is the combination of
management, financial, engineering, and
other practices applied to physical assets
such as plant, machinery, equipment,
buildings and structures in pursuit
of economic life cycle costs.

30. It is concerned with the reliability and
maintainability of physical assets and
also takes into account the processes of
installation, commissioning, operation,
maintenance, modification and
replacement.

31. References
1. en.wikipedia.org/wiki/Reliability_engineering
2. Institute of Electrical and Electronics Engineers (1990) IEEE Standard
Computer Dictionary: A Compilation of IEEE Standard Computer
Glossaries. New York, NY ISBN 1-55937-079-3
3. O'Connor, Patrick D. T. (2002), Practical Reliability Engineering (Fourth
Ed.), John Wiley & Sons, New York. ISBN 978-0-4708-4462-5.
4. http://lambdaconsulting.co.za/rwa%20barnard%20incose%202008.pdf
5. Federal Aviation Administration (19 March 2013). System Safety
Handbook (PDF). U.S. Department of Transportation. Retrieved 2 June
2013.
6. http://en.wikipedia.org/wiki/Terotechnology
7. http://www.reliableplant.com/Read/23083/role-reliability-engineer-
operations

32. Thank you for
Listening