A Tool For A Flexible Posterior Analysis Of Simulation Experiments

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-oriented processes whereby the simulation of business processes can be used to evaluate the quality of processes and to identify areas of improvements. For modeling of business processes as an event driven simulation model Rump(1999), Scheer(2000) we use the Epc-Simulator (Figure 1) as simulation system (Muller 2012), (Muller 2014a). Extensions of EpcSimulator are discussed in (Steglich and Muller 2013) and (Muller 2014) For analysis, the Epc-Analyzer (Muller and Kruger 2015), is presented and compared with the classical analysis approach. The functionality and use of EpcAnalyzer is demonstrated in a case study of Wildau University Library. CREATING A SIMULATION MODEL USING EPC-SIMULATOR For generating a simulation model with Epc-Simulator all required business processes must modeled as event process chains (EPC) in Bflow (Bflow 2014), (Kern et. al. 2010). Bflow is an EPC modeling system and runs as Beside the EPC diagrams, the available resource entities and the frequencies of master entities, that are running through the process chains, are described in a separate model diagram. The Epc-Simulator checks the validity of process chains and the model diagram. When all diagrams are valid the simulation model is generated as Figure 1: EpcSimulator concept image Proceedings 29th European Conference on Modelling and Simulation ©ECMS Valeri M. Mladenov, Petia Georgieva, Grisha Spasov, Galidiya Petrova (Editors) ISBN: 978-0-9932440-0-1 / ISBN: 978-0-9932440-1-8 (CD) a Java program. The simulation model uses the DesmoJ simulation frame-work (DesmoJ 2014), (Page 2005). DesmoJ runs with Apache 2 License (Apache License 2004). This concept is painted in the Epc-Simulator concept image (Figure 1). A sample process is shown in Figure 2. Every master entity that runs through this process is splitted at the first gateway into two parallel running siblings. At the second gateway both siblings are waiting together for synchronization and running afterwards into the next step as one integrated entity. For processing of function 0 and 3 resources are required. Before a master entity can pass this function it must wait for an available resource entity. For classical statistical analysis by Epc Simulator the data for all master and resource entities are registered. For master entities these are: • the process times inside a function, • the waiting time before entering a function, • the synchronization time inside a join gateway, • the lifetime and there • key performance indices. And for resource entities these are: • the process times inside a function, • there utilization and there • key performance indices. This data are stored in dependency of the observed entity and partially of the passed function or join gateway. For statistical representation the data are reported unchanged or aggregated as entity groups or function or join gateway groups. With an animation viewer application every simulation run can be animated in posterior. For this all changes of states of animated entities are stored during the simulation run in a file, named cmds file (Figure 4). The animation viewer reads the cmds file afterwards. The viewer can pause, restart and repeat the animation. It is also possible to have an detailed look on every entity. The writing of cmds file by simulation model increase its running time by a factor between 1.4 and 4.0. This is a result of some internal investigations. Figure 3 shows an animated simulation run of the example model. In the function nodes are some master entities processed together with there associated resource entities. In front of some function nodes are waiting master entities for processing. Inside the join gateway (17_AND) some paralleled siblings and there parent are waiting on synchronization.