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Fault density (ieee982.1-88)

A program under test can be assessed by counting and classifying the discovered faults by their types. For each fault class, fault density is measured as the ratio between the number of faults found and the size of the program

Life test, reliability evaluation

A statistical estimate of software reliability, which can be obtained by reliability achievement and evaluation, n be used to evaluate a product and decide whether or not testing can be stopped.

Reliability growth models

Reliability growth models provide a prediction of reliability based on the failures observed under reliability achievement and evaluation They assume, in general, that the faults that caused the observed failures have been fixed (although some models also accept imperfect fixes), and thus, on average, the product’s reliability exhibits an increasing trend. There now exist dozens of published models. Many are laid down on some common assumptions, while others differ. Notably, these models are divided into failure-count and time-between-failure models.

Evaluation of the tests performed

Coverage/thoroughness measures (ieee982.1-88)

Several test adequacy criteria require that the test cases systematically exercise a set of elements identified in the program or in the specifications. To evaluate the thoroughness of the executed tests, testers can monitor the elements covered, so that they can dynamically measure the ratio between covered elements and their total number. For example, it is possible to measure the percentage of covered branches in the program flowgraph, or that of the functional requirements exercised among those listed in the specifications document. Code-based adequacy criteria require appropriate instrumentation of the program under test.

Fault seeding

Some faults are artificially introduced into the program before test. When the tests are executed, some of these eeded faults will be revealed, and possibly some faults which were already there will be as well. In theory, depending on which of the artificial faults are discovered, and how many, testing effectiveness can be evaluated, and the remaining number of genuine faults can be estimated. In practice, statisticians question the distribution and representativeness of seeded faults relative to genuine faults and the small sample size on which any extrapolations are based. Some also argue that this technique should be used with great care, since inserting faults into software involves the obvious risk of leaving them there.

Mutation score

In mutation testing, the ratio of killed mutants to the total number of generated mutants can be a measure of the effectiveness of the executed test set.

Comparison and relative effectiveness of different techniques

Several studies have been conducted to compare the relative effectiveness of different test techniques. It is important to be precise as to the property against which the techniques are being assessed; what, for instance, is the exact meaning given to the term “effectiveness”? Possible interpretations are: the number of tests needed to find the first failure, the ratio of the number of faults found through testing to all the faults found during and after testing, or how much reliability was improved. Analytical and empirical comparisons between different techniques have been conducted according to each of the notions of effectiveness specified above.

Questions & Answers

Which of these are standards for assessing software processes
own Reply
team a found 342 errors during the software engineering process prior to release. team b found 184 errors. what additional measures would have to be made for projects a and b to determine which of the teams eliminated errors more efficiently? what metrics would you propose to help in making the determination? what historical data might be useful?
Kaviya Reply
it's depend upon software testing and debugging
OMKAR
what is coding
Waswa Reply
programming languages is a coding it is also used software development, designing, modeling, etc..
OMKAR
presently I work as a computer engineering what course can I study in any computer institute to enable me promoting myself
Ichaba
AND here lot of course
OMKAR
How to calculate the basic salary of a payroll in Java coding?
Adjei Reply
ত্তচুরভহব
Parvez
hello
Bahadur
Quids on software engineering
Enongene Reply
software testing practice
Prerana
definition of software
Baba Reply
define system ,concepts of system and types of system?
Gurmeet Reply
iom
ADNAN
hello
arsh
hari Paulus hai
Hari
System is the way of Execution or a set of principles to do something or any task is called System.
Ayesha
There are many infinite forms and Types of System in different fields as well.
Ayesha
TELL ME ABOUT MAINFRAME?
OMKAR
hi
Md
System is the way of Execution or a set of principles to do something or any task is called System.
Sazed
is very important software engineer or not.
Riyanshu Reply
very important
arsh
2d
Dv
hello
Md
what is software engineering
Ravindra Reply
Software engineering is a detailed study of engineering to the design, development and maintenance of software
arsh
what is salary of software engineer
Akash Reply
it depend on organization's and quality
josephat
I think average salary 80000us dollars per year
arsh
what are naturs of software Engineering
BANDARU Reply
what is the nature of saftware
BANDARU Reply
what is nature of sotfware
BANDARU
hi
khushboo
can anyone help me I need to learn
khushboo
code debug
khushboo
in eclipse java
khushboo
@janak can u suggest
khushboo
what is the salary of software engineer
Akash
per month
Akash
please tell me what is the salary of software engineer per monthe
Akash
HELLO ENGINEERS ✍
OMKAR
which sdlc mode l is suitable for atm banking system
Rakesh Reply
how can I create my own software?
David
HUAWEI.ABBULLAG.45720891
Abdula Reply
how to build apps
Andreas Reply

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Source:  OpenStax, Software engineering. OpenStax CNX. Jul 29, 2009 Download for free at http://cnx.org/content/col10790/1.1
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