You must first get to know why there is software?
. Accelerated pace of life, lack of time
Used to buy clothes: the clothing store, a family selection, try, go find a suitable payment, calculated how much money the clerk, customer payments
Now buy clothes: open shopping software, Taobao, Jingdong and so on input conditions, trade data show the form in front of users, customers select merchandise, the system automatically calculates the amount the customer online payment, direct debit from a bank card
The software now what?
APP: vibrato, micro letter, QQ, Taobao .........
WB end: city, Baidu ........
Public No.
Why software testing?
When using a program developed there will be a variety of defects, these soft can cause significant economic losses. The work of software testing is to find defects in the software, to reduce losses due to software defects caused.
What is software testing?
The industry is how to test the definition of the software. Hetzel in 1973 for an early definition of software testing, he said, "Software testing is to establish a program to run as expected confidence" is more of software testing is to ensure that there is confidence in the quality of a future software release. Now we are more generic definition of classic, 1979 proposed Myers, "the test is to discover errors during the execution of the program," the purpose of testing is to find errors, and the means by executing the program.
Now the latest definitions defined by IEEE (ISO / IEC / IEEE 29119), "using manual or automatic means to run or process measurement software system to verify that the software meets the system requirements and identify with between expected results differences " , means testing can be manual or automatic, and his aim is to find expected given the requirements of the software and our actual results have a difference between them, the purpose of the test is to find software that gap.
Software testing in the end what is it measured? What the test subject is? It is not to say that our software to test its test object is our software itself? This is the program I run itself? the answer is negative. In fact, software testing in the entire software development cycle, in fact, are there. Detailed design objects from his program to the needs of the early software outline design, software, software source code, the software program can be run, and even the final software running in this environment, we are testing software test object, that we software testing should cover all aspects of the software development life cycle.
Five Elements software
There are five major elements of software testing, is the quality of personnel, resources, processes, technology
The first principle is that the test shows the presence of a defect, but the system can not prove there is no defect . That is, through our software testing, we can find some software faults which exist, but after testing the software, I can not guarantee that this software is no fault.
The second principle is that exhaustive testing is not possible, the conditions should be set promptly terminated . We can not find all the problems among software, so we can not test the software endless, which should test test promptly set conditions for termination.
The third principle is that software testing should be performed as soon as possible . Let's look at a well-known software metrics in a chart:
FIG abscissa is different from a software development life cycle test phase, the ordinate is the proportion of a defect at different stages, several curves representing the various stages of the introduction of defects, the defect found at this stage and then fix at this stage the cost of defects takes. It can be seen from this figure, more defects are in the early development of our software introduced, but the cost to repair this defect is that we have developed over a period of continuous rise, the more the software developed by the late defects repair costs will be higher, so we are the most economical approach is to find defects as much as possible in our early research and development, and to repair these defects.
The fourth principle is that defects have cluster characteristics . In other words, most of the defects found among our test software and fail, often caused by a small number of software modules in a module, if we find more defects often means that there are more modules number of defects was not found. It found the problem more modules may be the worse the quality of this module. The level of our programming and software developers, experience and habits, etc. have a great relationship. So software defects have cluster characteristics, we have to focus on these issues and more module objects, the more we should focus more discovery.
The fifth principle is that pesticide paradox testing . That is, we test them, if the same test, the same test method, repeated to test a module, and finally not be able to re-discover new bugs, so we test cases and test methods should from time to time review and revision. And increases different test methods or test, to test different parts of the software system and to find more software defects.
The sixth principle is that the 28 principles of the test . Our test of time and resources are often limited, to find all the software errors and defects it is impossible, so it is always a risk test, this time to follow the principle that the 28 principles. That we should put 80% of the time and resources used in 20% of key modules, which focus on testing the software 20% of the important modules to achieve efficiency and resource configuration we tested the best of a scale.
The seventh principle is that testing activity on the testing background . Testing activities for different test background should be different, for example, our carrier-grade software might and our financial software, banking system, some related to performance, such a large amount of concurrent access have higher requirements, software security requirements may be higher, we often have to rely on testing activities are defined and designed for different test scenarios. Here are some basic principles of our software testing should follow.