Evaluation of a requirements engineering approach for adaptive component-based systems

Abstract

Component-based software engineering uses already existing building blocks of software (components) to develop new individual software. But sometimes it is possible that one or many of these used components have a malfunction. In such cases parts or the whole software doesn't work properly. To avoid this risk of malfunctioned components it is necessary to define one or many additional components which can also fulfil the requirements equally. Software which can handle this is called adaptive component-based software. Especially for adaptive software it is necessary to define the requirements in a way so that a set of fitting component candidates can be found among existing components. We propose an approach to define requirements for such an adaptive component-based software development.<br />Our CRRE (Circuit Response driven Requirements Engineering) process is based on SeCSE ESD (Service Centric System Engineering - Early Service Discovery). SeCSE is concerned with service-based software engineering which is one possible implementation of component-based software engineering. ESD is responsible to bring the consumer needs (requirements) in touch with the offered services.<br />We use the ESD process and enrich it on the one side with a definition of software borders. This should specify the consumer needs for the later software in a very coarse-grained way. We have also simplified some steps in the process to make it more comprehensible for the consumer. Last we have enriched it with a Feature Modification Model.<br />This model is necessary to define the software features in ranges, so that a candidate set of components can be found based on these features.<br />So it is possible to find more components which probably fulfil the consumer needs. As an initial evaluation we present a word processor as a case study. This word processor offer functionalities like a text editor or a spellchecker in combination with a thesaurus. Based on this case study we can show first results like a higher response rate of possible components. We found in average about one third more of adequate components in compare to traditional component-based approaches.