Regression testing

Basic forms of the trend tests (such as that of Tarone) have previously been presented in this text. These are a natural development from earlier methods of regression testing (Dinse and Lagakes, 1983), but are much more powerful. (Gaylor and Kodell, 2001). 

Trend analysis methods are a variation on the theme of regression testing. In the broadest sense, the methods are used to determine whether a sequence of observations taken over an ordered range of a variable (most commonly time) exhibit some form of pattern of change (either an increase-upward trend or decrease-downward trend) associated with another variable of interest (in toxicology, some form or measure of dosage and exposure). 

Mass balance, yields, and conversion were calculated. The yield to conversion functions were determined using linear regression. Tests with mass balances between 95 and 99 wt% were accepted. 

From National Toxicology Program (1993) Flepatocellular adenomas Squamous-cell papillomas and carcinomas p <0.05, logistic regression test p < 0.01, logistic regression test... 

System regression testing Make sure things that already worked before the changes were made still work. 

If any of the above testing fails, the developer is notified right away so that the bugs get fixed in the next build. Some open source tools can help to automate the testing. CruiseControl is a tool that automatically builds, deploys, and runs regression testing every time a code is checked into source control and notifies the person who checked in the code should problems be found. 

Regression testing must be executed in order to verify that all critical deviations were corrected. 

If applicable, perform regression testing of the application programs (OQ and PQ)... 

The impact of new versions of firmware and software on the validity of the existing qualification documentation should be reviewed and appropriate action taken. If applicable, after the new version is installed, regression testing should be conducted. The results of the regression test must be documented and approved by the appropriate personnel. 

The impact (criticality) of new versions on the standard product must be reviewed and appropriate action taken. After the new version has been installed, the new functionality must be tested and regression testing performed as part of the qualification activities. 

The replacement of hardware requires a formal IQ and, if applicable, regression testing to verily the correct integration of the hardware with the system and application software. When the hardware is replaced by an equivalent item (e.g., same model, revision, and manufacturer) it is necessary to record the details of the replacement part. 

When appropriate, regression testing (refer to Chapter 9) must be performed. The depth... 

Testing is necessary to determine whether the change works properly and has not compromised the system s functionality. The scope of testing should be based on the impact analysis. Where potential impact on other system functionality or other applications is identihed, testing must be extended to include affected areas. This is sometimes referred to as regression testing. 

During the operational life of the computer system, requirements traceability will enable impact assessments to be conducted in support of regression testing of changes. It is quite normal for a particular aspect of a computer system to require more than one test. When making a change, it is important to appreciate if this one-to-many situation exists and ensure that all appropriate tests are executed. 

Automated tools are best used for regression testing (to see if operation of the software remains the same after change). 

Regression testing verifies that modifications have had no impact on function or operation of the system. 

System failure during read/write operations Data retention following system failure Cyclical file management Prevention of duplicate record creation Referential integrity Impact on existing modules Regression testing... 

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