An Open Source Software Approach To Combine Simulation And Optimization Of Business Processes

Abstract

Business processes of modern companies are characterized by a huge complexity which is caused for example by quickly changing markets, short product life cycles or dynamic interactions between particular subsystems of a company. Business process management is intended to implement efficient and customer orientated processes whereby the simulation of business processes can be used to evaluate the quality of processes and to identify areas of improvements. Since real business processes usually contain decision processes which can be solved by optimization systems, it makes sense to combine the simulation and the optimization of business processes. (Marz et.al. 2010, p 3ff.) As an example of a reasonable combined simulation and optimization of business processes, the navigation in a road network is discussed in this paper. Consider vehicles seeking the fastest route from a starting node to a target node using a navigation system. The amount of time spent driving on an arc is influenced by the distance and the amount of the vehicles on this arc and is continuously changing. The structure of the road network and the traffic within the network is described in a simulation model while the fastest path decisions of each vehicle are made by using an optimization system. There is obviously a relationship between the individual decisions made for each of the vehicles and the state of the entire network. The aim of this paper is to describe how a combined simulation and optimization of business processes can be created through using EPC-Simulator (Muller 2012) as a simulation system and CMPL (Steglich and Schleiff 2010) as an optimization system where the network traffic simulation is used exemplarily. CREATING SIMULATIONS USING EPCSIMULATOR The EPC Simulator is a plugin of the EPC modelling toolbox bflow* (Kern et al. 2010). As shown in Figure 1 the first step to create a simulation model is the specification of a model document and several process documents in bflow*. The model document contains information about the model infrastructure (simulation time, available resources, inter-arrival times of entities, etc.). The process documents contain the process descriptions in EPC notation. Based on these documents, the EPC-Simulator can generate a simulation model. This is a Java Application that uses the DESMO-J Framework, whereby DESMO-J provides the basic functionality of a simulation. (Page and Kreutzer 2005) Figure 1: EPC-Simulator and its environment The Java source code generated by EPC-Simulator contains marked areas where the source code can be extended manually by individual functionalities in functions or decision rules. In this way it is possible to integrate CMPL easily by a code extension through