Dealing with Constraint-Based Processes: Declare and Supervisory Control Theory

The constraint-based processes are those that do not require a procedural model that explicitly specify the execution procedure. Declarative languages are more suitable for modeling and implementing this type of process. This paper aims to present and analyze two approaches that deal with the modeling and execution of constraint-based processes. The first approach makes use of Linear Temporal Logic and software Declare as a tool for modeling constraints. The second approach is based on the Supervisory Control Theory (SCT). Both approaches presented in this paper aims to monitor and restrict execution sequences of tasks such that constraints are not violated. Despite the control logic is built based on constraints, it does not limit the user by imposing rigid control-flow structures. A discussion of the results, advantages and the main drawbacks of the two approaches are presented in this paper.