Analyzing workflows implied by instance-dependent access rules

Abstract

Recently proposed form-based web information systems liberate the capture and reuse of data in organizations by substituting the development of technical implementations of electronic forms for the conceptual modelling of forms' tree-structured schemas and their data access rules. Significantly, these instance-dependent rules also imply a workflow process associated to a form, eliminating the need for a costly workflow design phase. Instead, the workflows thus created in an ad hoc manner by unsophisticated end-users can be automatically analyzed, and incorrect forms rejected. This paper examines fundamental correctness properties of workflows that are implied by instance-dependent access rules. Specifically, we study the decidability of the form completability property and the semi-soundness of a form's workflow. These problems are affected by a choice of constraints on the path language used to express access rules and completion formulas, and on the depth of the form's schema tree. Hence, we study these problems by examining them in the context of several different fragments determined by such constraints.