A Full R/I-Net Construct Lexicon for Declare Constraints

Abstract

Recently, declarative process languages are gaining ground as the procedural way of capturing activities in a fixed work-flow is deemed to be inflexible. Declare, one of the prime languages of the declarative process modeling paradigm, is composed of logic-based activity constraints which are event-driven. In this paper, a template-based conversion is proposed of every Declare constraint into a single Petri net fragment with weighted, reset and inhibitor arcs, i.e. a weighted R/I-net. As such, a formalization of the execution semantics of Declare is obtained, similar to linear temporal logic or regular expressions, but now expressed in the form of Petri nets. Equivalence of Declare constraints and the respective Petri net templates are analyzed at the theoretical level and by means of a simulation experiment.