Master Thesis Anja Bog
A Visual Environment for the Simulation of Business Processes based on the Pi-Calculus
© 2006 Anja Bog
The π-calculus poses as a serious alternative to existing approaches for formal represen- tation and modeling of business processes. In contrast to traditional formal modeling techniques, like Petri nets and enhancements of Petri nets for process pattern support (e.g. Workflow nets, YAWL), the π-calculus additionally offers the possibility to model systems with dynamic structures. In such systems, the actors as well as the communication links between these actors are subject to changes, e.g. omission of existing actors or addition of new actors and communication links, respectively. With regard to the increasing relevance of service oriented architectures, i.e. systems with dynamic structures, the interest in modeling techniques for processes being able to describe these properties rises and lets the π-calculus come to the fore.
This thesis deals with the development of a software application for the execution and observation of business processes based on the π-calculus. Starting from explanations of the basic principles of business processes, business process modeling, business process management and the π-calculus, the concepts for the development of a simulation environment for π-calculus processes are described. These concepts comprise both, ideas for the design of an execution engine for π-calculus processes as well as their graphical representation. The execution engine requires an internal data structure for storing and handling the processes. This data structure and appropriate rules for processing the data structure are defined.
Besides the execution of π-calculus processes, the user of the simulation environment is offered interactive means for exerting influence on the further evolution behavior of the observed system. Interactions become manifest, for example, in choosing the next communication step or adding new actors to the system that are immediately able to communicate with already existing actors. An intuitional use, which allows a user to directly manipulate the graphical representation, is striven for. Existing approaches for graphically representing π-calculus processes are analyzed. One of them is extended to obtain an adequate graphical representation for the simulation environment and to provide sufficient information for user interaction.
Moreover, the scope of this work contains a prototypical implementation of the elaborated concepts. The requirements for the prototype of the simulation environment and the resultant architecture as well as its implementation are described. The appearance and functionality of the prototype are presented by means of an example, subsequently.