Validating Specifications for Model-Based Testing

In m odel-based testing the behavior of a system u n d er test is com pared autom atically w ith the behavior of a model. A significant fraction of issues found in testing appear to be caused by m istakes in the model. In o rd e r to ensure th a t it prescribes the desired behavior, it has to be validated by a hum an. In this w ork we describe a tool, esm V iz, to support this validation. M odels a re given in a pure, lazy functional p ro ­ gram m ing language. esm V iz provides an interactive sim ulator o f the model, as well as d iagram s of the observed behavior. The tool is built on the iTask toolkit w hich results in an extremely concise G U I definition. E xperim ents show th a t esm V iz helps to gain understanding of a m odel and to detect and rem edy errors.