<< Chapter < Page
  Software engineering     Page 5 / 15
Chapter >> Page >

Software reliability refers to the probability of failure-free operation of a system. It is related to many aspects of software, including the testing process. Directly estimating software reliability by quantifying its related factors can be difficult. Testing is an effective sampling method to measure software reliability. Guided by the operational profile, software testing (usually black-box testing) can be used to obtain failure data, and an estimation model can be further used to analyze the data to estimate the present reliability and predict future reliability. Therefore, based on the estimation, the developers can decide whether to release the software, and the users can decide whether to adopt and use the software. Risk of using software can also be assessed based on reliability information. The primary goal of testing should be to measure the dependability of tested software.

There is agreement on the intuitive meaning of dependable software: it does not fail in unexpected or catastrophic ways. Robustness testing and stress testing are variances of reliability testing based on this simple criterion.

The robustness of a software component is the degree to which it can function correctly in the presence of exceptional inputs or stressful environmental conditions. Robustness testing differs with correctness testing in the sense that the functional correctness of the software is not of concern. It only watches for robustness problems such as machine crashes, process hangs or abnormal termination. The oracle is relatively simple, therefore robustness testing can be made more portable and scalable than correctness testing. This research has drawn more and more interests recently, most of which uses commercial operating systems as their target.

Stress testing, or load testing, is often used to test the whole system rather than the software alone. In such tests the software or system are exercised with or beyond the specified limits. Typical stress includes resource exhaustion, bursts of activities, and sustained high loads.

Regression testing

According to (IEEE610.12-90), regression testing is the “selective retesting of a system or component to verify that modifications have not caused unintended effects...” In practice, the idea is to show that software which previously passed the tests still does. Beizer defines it as any repetition of tests intended to show that the software’s behavior is unchanged, except insofar as required. Obviously a trade-off must be made between the assurance given by regression testing every time a change is made and the resources required to do that.

Regression testing can be conducted at each of the test levels. The target of the test and may apply to functional and nonfunctional testing.

Correctness testing

Correctness is the minimum requirement of software, the essential purpose of testing. Correctness testing will need some type of oracle, to tell the right behavior from the wrong one. The tester may or may not know the inside details of the software module under test, e.g. control flow, data flow, etc. Therefore, either a white-box point of view or black-box point of view can be taken in testing software. We must note that the black-box and white-box ideas are not limited in correctness testing only.

Questions & Answers

how to build apps
Andreas Reply
what is memory?
Hausa Reply
memory is billions of consecutive data storage cell where each of the cell has its own particular address of identification.
Shariful
what are the major difference in the external environment of an office automation system and that of an embedded systems
juma Reply
What is software engineering
Zohaib Reply
what is salary of a software engineer
Akash Reply
understand wllhi 😭am language somali bro 😇😣😣😣
what is agile
Qais Reply
what do you want
help
Billy
how to U download
Adam Reply
hi is there any mobile spy app best you know?
muddy Reply
what is software engineer
Soumen Reply
Who make the software he is the software engineer.
thando
i don't
Al
mobile spy android need it any one help me
muddy
🤔
I want to create a game
Rohith Reply
Requirements to create game
Rohith
yes i also
GURPREET
want to knoe about the reqirements
GURPREET
Yes
Rohith
what are software evolution processes
Software Evolution is a term which refers to the process of developing software initially, then timely updating it for various reasons, i.e., to add new features or to remove obsolete functionalities etc. ... If the proposed changes are accepted, a new release of the software system is planned
Fenkil
basic things of software engineer
Saroj Reply
Which languages need for web development? And how I can learn it? pls help me
Zhamshid Reply
basic things of software engineer
Saroj
hm
Dhruv
I also want to know basic training for software engineering
Dhruv

Get the best Software engineering course in your pocket!





Source:  OpenStax, Software engineering. OpenStax CNX. Jul 29, 2009 Download for free at http://cnx.org/content/col10790/1.1
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Software engineering' conversation and receive update notifications?

Ask