Lightweight task modelling for system design

This paper describes a method for system design based on task modelling, alongside with software allowing to set up task models and translate them into UML use cases and use case descriptions. Some major task modelling methods are briefly considered to point at the broad context in which the conceptual framework has been designed. While introducing a resolute user-centered bias in the design process, the method builds on a simple set of categories (objects, facets, operations) combining into the descriptions and actions that populate task content (pre- and post-conditions, input, output, steps). As combination types are very limited, formal expressions translate easily into the controlled language used to specify tasks within the software.