Why is software which can introduce defects?
As long as people will make mistakes. Even a good programmer will commit low-level nature of the error, according to statistics, even the best programmers, developers of software products, if not tested, legacy code defects per thousand lines of code in at least 6 or more.
Common root cause of flawed software are:
1, lack of effective communication, or no communication
2, software complexity
3, programming errors
4, constantly changing needs
5 pressure, time
6, the lack of documentation of the code
7, software development tools
8, arrogant person
The type and severity of defects
Software error (software error)
Software bugs (software defect)
Software fault (software fault)
Software failure (software failure)
Software failure mechanism can be described as: software error -> Software Defect -> Software fault -> software failure
Software error: at each stage of the software life cycle, runs through people directly or indirectly intervene. However, people will inevitably make mistakes, this software is bound to leave a bad mark. Refers to software errors in the software for the lifetime of unwanted or unacceptable thought wrong, the result is to generate leads software defects. Visible, the software error is a human process, as opposed to the software itself, it is an external behavior.
Software defects: those software defects are undesirable or unacceptable deviations present in the software (documents, data, programs) among as few a comma, a multi-statement, etc., which result in the software running when a particular condition occurs software failure, said the software defects are then activated.
Software failure: software failure refers to the internal state of software process appears not want or do not accept. For example, an extra software in the implementation cycle, we say that the software is faulty. At this time, the absence of appropriate measures (fault tolerance) to be in time, will produce software failure. Therefore, the software failure is a dynamic behavior.
Software failure: failure refers to a software generated software is running does not want or does not accept the results of the external behavior.
In summary, the software error is a human error. A software error must produce one or more software defects. When a software bug is activated, it generates a software fault; the same software defect is activated under different conditions, may produce different software failures. Software fault tolerant if there is no timely measures to deal with, will inevitably lead to software failure; failure may result in different software under different conditions with a software failure.
Software Defect severity and priority
Severity:
Fatal: The system crashes, data loss, data corruption;
Severity: operational errors, incorrect results, missing function;
General: error message, UI layout, operation for too long;
Minor: the error does not affect or achieve better use.
priority:
The highest priority: repair immediately stop all testing;
The next highest priority: to be repaired between the product release;
Medium priority: If time permits should fix;
Lowest priority: it may fix, but can also be released.
General severity and prioritize the use of numbers 1 to 4 show the highest level of the digital representation of some small; and some with a large high-level digital representation;
What is the test?
Test case (Test Case) is to design a case, the software program in this case, must be able to function properly and achieve the results of programming.
Benefit test is mainly reflected in the following areas:
Before starting the test design a good test case, avoid blind test and improve test efficiency;
Software testing test cases to make use of the implementation of focused and purposeful;
In the updated version of the software need only a small number of test cases can be corrected to carry out testing, reduce the work intensity, shorten the project cycle;
Universal function modules and reuse of the software is easy to carry, and generalization of the test case and reuse of software testing is so easy to carry out, and with the constant essence of the test case of its efficiency is also rising.
What is the test execution?
Test execution is to run the software under test according to the test case.
Test execution of a test case
Test execution of a test suite
What are the main test engineers are working?
View the code, review development documents;
Test design, writing test documentation (test plan, test plan, test cases, etc.);
Perform testing, software defects found, post bug reports, and finally confirmed defects have been corrected;
By testing measure software quality.