TADEUS: Seamless development of task-based and user-oriented interfaces

Task-based and user-oriented user interfaces utilize knowledge about user tasks and end user characteristics to the utmost extent, They not only support end users throughout the work flows they are involved in their business, but need also to be constructed throughout a development process that allows to proceed without loss of application context and user feedback from requirements specification to code generation. The concepts behind the task analysis/design/end users systems (TADEUS) approach to enable seamless development based on end user tasks are a semantically rich representation scheme, a model-driven development procedure, a diagrammatic notation and unifying specification scheme. They are to be used for task analysis, design, and code generation. This way, interactive applications can be developed seamlessly, starting with task analysis, proceeding with design, and generating customized user interfaces for the actual task performers (users), Specifications comprise problem domain knowledge, work processes, user roles and personal profiles, as well as interaction modalities (required for task accomplishment). For user-interface prototyping the TADEUS environment contains a model interpreter that executes structure and behavior specifications. This way, early feedback on task-based portals can be provided by users. In this paper we detail the latest developments in the TADEUS project when implementing a work-process based usability life cycle. We review the underlying methodology and the features of the TADEUS environment, in order to demonstrate the benefits for developers and users resulting of smooth transition support for and between the different stages of development.