The Role of BPMN in a Modeling Methodology for Dynamic Process Solutions

This paper introduces a design method for dynamic business process management solutions in which the well-known modeling elements of business object life cycles, business rules, and business activities are integrated in a distributed system as equal communicating components. Using the EURENT car rental domain originally developed by the business rules community, it is demonstrated how this method can be used to enable adhoc and rule-driven activities integrated with the life cycle management of business objects. A modeling methodology based on BPMN collaboration diagrams is proposed to describe component interactions and behavior. Agile principles are applicable to incrementally build the solution in which scenarios play a major role to validate and further evolve the solution’s behavior. A clear separation between components, their interaction, and details of the internal component behavior facilitates change and the implementation of business patterns. 1 Towards Dynamic Process Solutions Over the past years, the Business Process Management (BPM) community has been increasingly discussing more flexible BPM solutions that have a stronger focus on data and offer simple, yet powerful ways to integrate business rules. For example, the authors of [1] discuss case handling as a paradigm for dynamic BPM solutions and identify the following requirements: – Avoid context tunneling and provide all information relevant to a case as needed, not just the information subset required to execute an activity within a predefined process flow. – Decide which activities are enabled on the basis of the available information rather than enforcing a specific activity flow. – Separate work distribution from authorization instead of using activity-based routing as a single mechanism to simultaneously address both requirements. In addition, a dynamic BPM solution must support actor-initiated activities, which means that the human participants in a business process should be able to decide when to perform a business function. However, business conduct as captured in business rules should always be followed and monitored. Business rules should thus not only be used as automated decisions as it is common today, but they should primarily serve to establish obligations for actors to perform activities within the boundaries of appropriate business conduct. This paper proposes a modeling methodology that addresses the above-mentioned requirements. It proposes a shift from the explicit modeling of predefined end-to-end processes to an agile design approach where the business capabilities (activities) of actors, the business rules that initiate and govern actor behavior, and the life cycles of the main business objects move into the primary focus of attention. Activities, rules, and life cycles are considered as three types of equal communicating components in a distributed system. None of the three component types is subordinate to the other; they interact via message exchanges with each component type having different capabilities. Whereas activities, business rules, and object life cycles are wellknown modeling elements, their equal interaction and uniform representation has not been investigated so far. The paper explores the consequences of such an integrated approach for a BPM solution. Instead of proposing a new modeling language, the approach relies on BPMN 2.0 [2] and introduces a modeling methodology using BPMN collaboration diagrams to specify a dynamic process solution. By using BPMN, a uniform representation of activity, rule, and object life cycle components is achieved, which integrates all functional aspects of a BPM solution in a seamless manner. As BPMN 2.0 strives for a new level of integrating business-user-friendly modeling with direct model execution, the immediate exploration and simulation of process scenarios during modeling will help to build dynamic process solutions of high quality. The paper uses a subset of the EURENT domain that models the typical operations of the branch office of a car rental company containing many adhoc activities and more than 100 business rules [3, 4]. To validate the proposed methodology, parts of the domain were implemented using the process engine ePVM [5]. As the methodology is independent of a particular runtime engine, the discussion in this paper focuses on the conceptual pillars and abstracts from implementation details. The paper is organized as follows: Section 2 introduces the main idea and shows examples of the three component types business rules, object life cycles, and actors in the EURENT domain. In Section 3, a 3-layer architecture as the foundation of the dynamic BPM solution is discussed, whereas Section 4 introduces principles of component interaction and BPMN collaboration diagrams as a means to specify component communication and behavior. Section 5 identifies next steps in research to further mature the proposed approach. Section 6 summarizes related work and Section 7 concludes. 2 Actors, Rules, and Object Life Cycles as Equal Communicating Components The basic idea of the proposed modeling methodology is simple. Instead of modeling a process by capturing the flow of activities, refining this flow with data, adding roles to activities, and eventually refining decisions with business rules, the focus shifts to actors and their business capabilities, business objects capturing the main data and possessing a life cycle, as well as business rules establishing obligations for actors. Actors, object life cycles, and business rules form three types of communicating components where none has control over the other. The interaction of the components using messages creates the end-to-end process.