Reliability Engineering, ENGI 8670/9116
Midterm Test
June 19, 2014
Duration: 60 minutes
Evaluation: 25%
Dr. Faisal Khan & Dr. Nima Khakzad
Referring to Book/Notes/Assignments Permitted
Section A (5%) (10 minutes)
Q1. Answer the following questions precise
Chapter 9: Exercise Questions
1. A system consists of three components in series having the following
parameters:
Components
1
2
3
Current reliability
0.85
0.80
0.90
Cost coefficient
$25
$20
$40
The upper bound reliability is 0.99, and system reliability
Assignment 4: Reliability of systems
Due date: Thursday, July 10th, 2014
1. Find the minimum number of redundunt components, each having a reliability of 0.4,
necessary to achieve a system reliability of 0.95. There is also a common mode
failure probabili
Reliability engineering
The Failure distributions
Including the
exponential, Weibull, extreme value, normal, lognormal and gamma.
The time to failure of a typical household vacuum
cleaner made by the Kanknot Cleane Company has
the following probability de
Problem solved in class
Introduction
1. A two component parallel system is in failure state (both components are failed)
4% of time. Component 1 is in failed state 8% of time whereas component 2 is in
failed state for 6% of the time. Compute different pro
Assignment # 6: Physical reliability models
Due Date: 31 July 2014
1. The time to failure of a drill bit is lognormal with s = 1.43. From field data the median
life of the bit has been found to depend on the hardness and the density of the material
being
Design for Reliability
Reliability design
Reliability is an inherent attribute
It is important in analyzing the system
life-cycle-cost
Reliability design is an iterative process
that begins with
the specification of reliability goals
cost association an
Problem solved in class
Introduction
1. A two component parallel system is in failure state (both components are failed)
4% of time. Component 1 is in failed state 8% of time whereas component 2 is in
failed state for 6% of the time. Compute different pro
Chapter 1: Reflective Questions
1. Who is primarily responsible for the engine failure of a newly-purchased car?
(a). Driver
(b). Design Engineer
(c). Manager
2. According to you, which factor is most important while selecting a product?
(a). Cost
(b). La
Failure distribution
1
Failure Distribution
While thinking of developing mathematical models to describe the
reliability of components or systems, four probability functions
are important. They are reliability function, cumulative
distribution function, p
Time dependent failure models
1
Time Dependent Failure Models
The time dependent failure processes can be modeled using Weibull,
normal and lognormal distributions. These distributions
have hazard rate functions that are not constant over time,
thus provi
Reliability of systems
1
Reliability of Systems
This section deals with determining the system reliability. One
approach to analyze a complex system is to apply a
particular failure law to the entire system. An alternate
approach is to determine an approp
State dependent model: Markov analysis
1
State-Dependent Systems: Markov Analysis
A fundamental computation in reliability engineering is the
determination of system reliability from the knowledge of component
reliabilities and their system configuration.
Introduction to Reliability engineering
1
Introduction to Reliability Engineering
Introduction
Things fail in nature. Examples of such failures are the cracking of
lawn-mower chasing, failure of a washing machine and car battery,
burning of a toaster oven
Chapter 3: Exercise Questions
1. Consider the probability density function.
t 0
0.002e 0.002t
f (t )
otherwise
0
for t is in hours
Calculate reliability function, failure times, and design life if a reliability of 0.95
is desired.
2. Prove that reliabil
Quiz #2 A Mighty Fine
Review
February 27: A reliable
adventure; a day like all days
filled with those events that
alter and change the course of
historyand you will be there!
What is a Quiz #2?
Three problems to work from chapters 5, 6 and 7
Each question
INGESTION
Agent
C
DDT
Ammonia
DERMAL
Agent
C
DDT
Ammonia
CR
0.000001
35
EF
2
2
SA
0.000001
35
ED
365
365
PC
18150
18150
INHALATION
Agent
C
CR
EF
DDT
0.000001
32.9
Ammonia
0.2
0.002
RR
33
33
ABS
0.001
0.0025
CF
0.03
0.03
ED
365
365
ABS
1
1
ET
0.001
0.001
R
A Quiz #3 most
excellent review
ENM 565 Reliability Engineering
Another opportunity to do good
The Glorious Exam
z
z
Date/Time: Monday, March 25: 4:30 pm to
5:45 pm
Topic: chapters 9 -11, a single component
z
z
z
Either a renewal process or minimal repair
Section 14.4.1 Maximum Likelihood Estimation
b=
a=
0.286850489
1.013008999
enter ts =
12035
ab =
(t ) abt b 1, a, b 0, t 0
0.2905821263
E N (t ) at b
enter failure times, ti, in ascending order
ti
count
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Assignment # 7
Design for Reliability
Submission Date: August 5, 2014
1.
In the design of a space station, four major subsystems have been identified, each having
a Weibull failure distribution with parameter values as given here:
Subsystem
Computer
Avion
Reliability Assessment of Subsea X-mas
Tree Configurations
Petter Gullhav Wanvik
Subsea Technology
Submission date: June 2015
Supervisor:
Anne Barros, IPK
Co-supervisor:
Marvin Rausand, IPK
Norwegian University of Science and Technology
Department of Prod
Question 1: Journal Paper Review
Paper Title: A predictive approach to fitness-for-service assessment of pitting corrosion
Authors: Elahe Shekari, Faisal Khan, Salim Ahmed.
Publication and year: International Journal of Pressure Vessels and Piping 137 (20
Chapter 2: Exercise Questions
1. A two component parallel system is in failure state (both components are failed)
4% of time. Component 1 is in failed state 8% of time whereas component 2 is in
failed state for 6% of the time. Compute different probabilit
Memorial University
Faculty of Engineering & Applied Science
Reliability Engineering, ENG. 8670
Final Examination
12th April 2010
Duration: Two and half hours (150 minutes)
Evaluation: 40%
Faisal I Khan
Question paper has three sections (A, B, and C) and
Term Design Project Guidelines
Learning objective:
To have design application of the reliability engineering concepts
Rationale
The goal of term project in this course is to provide a demonstration the understanding of
the course material through a design
Physical reliability models
1
Physical Reliability Models
So far the study was focused on development of reliability models in
which the system or component reliability was considered as a function
of time only. In many applications, other factors may be