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Performance testing

Not all software systems have specifications on performance explicitly. But every system will have implicit performance requirements. The software should not take infinite time or infinite resource to execute. "Performance bugs" sometimes are used to refer to those design problems in software that cause the system performance to degrade.

Performance has always been a great concern and a driving force of computer evolution. Performance evaluation of a software system usually includes: resource usage, throughput, stimulus-response time and queue lengths detailing the average or maximum number of tasks waiting to be serviced by selected resources. Typical resources that need to be considered include network bandwidth requirements, CPU cycles, disk space, disk access operations, and memory usage. The goal of performance testing can be performance bottleneck identification, performance comparison and evaluation, etc. The typical method of doing performance testing is using a benchmark - a program, workload or trace designed to be representative of the typical system usage.

Security testing

Software quality, reliability and security are tightly coupled. Flaws in software can be exploited by intruders to open security holes. With the development of the Internet, software security problems are becoming even more severe.

Many critical software applications and services have integrated security measures against malicious attacks. The purpose of security testing of these systems include identifying and removing software flaws that may potentially lead to security violations, and validating the effectiveness of security measures. Simulated security attacks can be performed to find vulnerabilities.

Testing automation

Software testing can be very costly. Automation is a good way to cut down time and cost. Software testing tools and techniques usually suffer from a lack of generic applicability and scalability. The reason is straight-forward. In order to automate the process, we have to have some ways to generate oracles from the specification, and generate test cases to test the target software against the oracles to decide their correctness. Today we still don't have a full-scale system that has achieved this goal. In general, significant amount of human intervention is still needed in testing. The degree of automation remains at the automated test script level.

The problem is lessened in reliability testing and performance testing. In robustness testing, the simple specification and oracle: doesn't crash, doesn't hang suffices. Similar simple metrics can also be used in stress testing.

When to stop testing?

Testing is potentially endless. We can not test till all the defects are unearthed and removed - it is simply impossible. At some point, we have to stop testing and ship the software. The question is when.

Realistically, testing is a trade-off between budget, time and quality. It is driven by profit models. The pessimistic, and unfortunately most often used approach is to stop testing whenever some, or any of the allocated resources - time, budget, or test cases - are exhausted. The optimistic stopping rule is to stop testing when either reliability meets the requirement, or the benefit from continuing testing cannot justify the testing cost. This will usually require the use of reliability models to evaluate and predict reliability of the software under test. Each evaluation requires repeated running of the following cycle: failure data gathering - modeling - prediction. This method does not fit well for ultra-dependable systems, however, because the real field failure data will take too long to accumulate.

Questions & Answers

Which SDLC Model will you select to develop the system as a software engineer and why?
Subrato Reply
communication techniques in software development
SANJANA Reply
👋👋👋
Aslam
what is communication techniques in software development
Aslam
hii
Ritika
hi
prabhu
Hlw
Subrato
hi
Pedro
who is Charles Babbage
Marvin Reply
is father of computer
Pedro
how to do documents in the computer
Mark Reply
Kashmir
akmal
k
akmal
hello
Anil
Hi
Rohid
how are you?
Rohid
Which of these are standards for assessing software processes
own Reply
hello teacher may I give me example of format of software
Aurianne
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
Hi, Everyone
Rohid
how can ,I download windows 10 pleases
Pedro
hello
Pedro
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
but we have tobe serious in k.dge.. what is the meaning of java coding if you are gineous you will answer me
Eyiba
hie
Mark
hi
Rana
Quids on software engineering
Enongene Reply
software testing practice
Prerana
Ho
Rang
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
hi
Rohid
hi
martin
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

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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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