Testing-based assessment process for upgrading component systems

Updating component-based systems demand a careful treatment due to stability risks. Replacement components must be analysed on behaviour equivalence for the provided functionality. Our proposal complements the conventional compatibility analysis with black-box testing criteria as a support for substitutability. The aim is to analyse functions of data transformation encapsulated on components, i.e. their behaviour. This is reflected by the observability testing metric. For a piece under substitution, a component behaviour test suite is built for being later applied on candidate replacement components. The approach is supported through a tool, testooj, which is focused on testing Java components.