A Relational Algebraic Approach to the Representation and Analysis of Discrete Event Systems

The analysis and control of discrete event systems modeled by finite-state machines require possibly complex manipulations of these finite-state machines. Algorithms that involve such manipulations must be described formally, uniformly, concisely, and must be easy to program. This paper shows that the relational algebra from relational database theory can be employed to achieve these goals. We consider representative operations on finite-state machines that arise in the analysis and control of discrete event systems and show how these operations can be formally specified as algebraic expressions in relational algebra and how they can be implemented as SQL queries on a relational database management system.