WRAD: Tool Support for Workflow Resiliency Analysis and Design

Designing efficient workflows is complex especially when considering security constraints that restrict which users can perform which tasks. This is further exacerbated when considering users could become unavailable at runtime, which is known as the workflow resiliency problem. Ideally, designers undertake resiliency analysis at the design stage so that the likely impact of security constraints on a workflow can be assessed before its execution. In this paper, we describe a new tool called Workflow Resiliency Analysis and Design (WRAD) which automatically encodes a textual description of a workflow into the probabilistic model-checker PRISM, and carries out a resiliency evaluation. WRAD also computes optimal change sets for security constraints to assure a given resiliency threshold is reached.