Enhanced Traceability for the Unified Process

Complex, business critical software systems have to adapt to frequently changing needs. Evolutionary development processes have been developed to enable short responses to changes. In complex settings the changes bear high risks, such as incomplete implementation, misunderstood depen- dencies, missing comprehension and lacking coverage. To manage these risks, the concept of traceability has been de- veloped and introduced to most development process stan- dards. However, we have to state that traceability is poorly used in practice, mostly limited to tracing requirements. Nevertheless, traceability links are needed to connect de- sign and implementation elements as well. To be useful, traceability links have to be defined at a fine-grained level and maintained in a correct and complete state. Since a high number of links has to be managed, and the mainte- nance tasks have to be carried out manually, an extremely high eort is required. Tool support would be very helpful, Based on that, all required links between the artefacts of the UP activities of requirements engineering and design are chosen out of the amount of all possible valid links. Ad- ditionally, a syntactical and semantical definition of trace- ability links is established, customized to the UP's methods. These steps lead us to a milestone and provide a basis for further works e.g., empirical investigations for rules concern- ing the suitable level of detail for traceability links, or for rules how far to follow traceability links during the impact analysis of a change. As results of these works, guidelines for the level of detail and rules for the verification of traceability links have been established. The analysis of the UP and the customisation of the traceability link model are performed during practical development projects. Currently, the developed traceability link model is refined towards a detailed level of coverage of the methodical activ- ities, to facilitate appropriate tool support for the creation, update and verification of the traceability links with a mini- mum interaction with the developer. To extend the UP's de- velopment methods, the architectural design method Qasar (1) is integrated into them. Other development methods and processes like Fusion (2) and Refactoring (3) are currently investigated aiming to- wards a generally usable traceability model. For the realisa- tion of tool support we have started the implementation of extensions for existing UML tools. The extensions will sup- port the developer by the establishment of traceability links in the background while modelling and by maintaining the consistency of existing links during changes of artefacts. To extend the practical application of traceability links, trace- ability link model is currently implemented by two major CASE-Tool vendors. Furthermore, it is integrated to project management methods and software process models.