Organization and stages of testing when testing the reliability of software.

The stages of testing software packages.
Testing and testing of PS as a whole consists of the following steps:
1. tests in real time according to the generators of tests that imitate separate objects of the external environment;
2. tests in real time with simulators of individual objects of the external environment and with real impacts from operators-users;
3. tests in a fully adequate real or simulated external environment and with real impacts from user operators.
At all stages, in addition to direct testing of the functioning of the programs, 2 more types of work are performed: 1- work on methodical support of testing and the creation of automated test generation tools and 2 - processing test results and evaluation of the achieved program quality indicators.
Each of the stages of testing provides for the creation of a specific intermediate product. Each stage must have a document confirming the results of the achieved program characteristics.

Organization of final testing of the program complexes.
The final tests of the program complexes are carried out in two ways, depending on the availability of customers.
If a set of programs has been developed for a specific customer, the maintenance tests are carried out jointly, in which the customer and the developers take part. A commission is created that checks the fulfillment of the requirements of the technical specification and the compliance of the PS with the documentation submitted. In the final tests, in addition to functional validation checks, it is necessary to conduct testing in the modes of limiting the use of resources to verify the reliability of the PS.
Testing of commercial software packages created by developers on the initiative in the absence of a specific customer is carried out in 2 stages, which are called Alpha - and Beta-testing. Tests are carried out pas compliance with the criteria defined by the project manager. They consist of normal and accelerated trial operation by the end users of the software product in accordance with the accompanying documentation.
Alpha testing involves end users working for the same company, but not directly involved in the development of this set of programs. For Beta testing, voluntary users are involved who receive a free version of the PS for trial operation. These users are obliged to inform developers of any defects and errors found and to replace versions according to the instructions of the developers. After successful Beta testing, a decision is made on the transfer of PS for sale to a wide range of users. A summary of Beta testing results can be used as part of certification tests.
In Alpha and Beta testing, accept separate progressive and regressive testing. Progressive means testing new software components to identify defects and errors in source programs and specifications. Regression testing is designed to control the quality and correctness of changes in programs after making adjustments. The necessity and breadth of regression testing is determined by the fact that a significant proportion of changes after Alpha and Beta testing, in turn, contain errors. The scope of tests and the duration of both stages are determined by the project manager depending on the complexity of the program complex.