Master Thesis

ion for IBs because if it is not defined clearly which leads to ambiguity in discussions and publications. In TALL, the agent-role diagram and the role-interaction diagram have been used to model agents, roles, and the (dynamic) interactions between them. However, the choice to draw the agent-role diagram at the instance level and to draw the role-interaction diagram at the type level is not scientifically grounded. Therefore, the level of abstraction must also be defined for these diagrams. In addition, the role concept that appears in these diagrams must be clarified because it is not clear what the abstraction level of a role is and how roles should be depicted in the two diagrams. 2.1.2 Interaction Decomposition TALL is interaction centred and agent-oriented, which means that communication, negotiation, collaboration, cooperation and coordination between agents, either human or artificial, have the focus. As discussed in chapter 1 each local view of the agents involved in interactions is presented as IBs. For each IB a separate IB diagram shows the process view of a specific agent (who plays a specific role). In the current version of TALL, much is unclear about the role-interaction diagram and the IB diagrams. For instance, when an interaction is surrounded by ten roles does this mean that all of these roles are interacting? To answer this question an interaction has to be defined more precisely. As explained due to the agent-orientation each participant has to have its own local view of the process. On a high level of abstraction, TALL allows an entire process to be described as a single over-encompassing interaction. From a modelling perspective, such a representation is very simple but at the same time, its simplicity reduces the expressiveness and richness of the model. From the perspective of the agents performing the roles, such a conceptual interaction is very complex and undesirable. To be useful, it is necessary to decompose a high-level interaction into ‘smaller’ interactions in a top-down analysis fashion. Alternatively, it is possible to have a set of interactions where all interactions are elementary interactions (i.e. these cannot be decomposed further). Such a set of interactions is not very useful either, because we want to be able to show a coupling between the interactions. There is clearly a need to define interactions that are “in between” the overall BP-describing interaction and the elementary interactions. In our view, interactions are compositional; they can be grouped and divided. In short, it is important to make some ontological commitments concerning the interaction concept, and research how it can be decomposed into possible subinteractions. 2.2 Research Justification It is a common notice that most existing processes in companies are not as efficient as they could be and that new technologies can be used to design processes that are more efficient. A business process redesign or improvement effort usually starts with the analysis of an existing business processes after which the process is improved, (re)designed or automated. Finally, the changed business process is implemented. A business process change cycle is shown in figure 2-1, which is a general description of the lifecycle of business processes. The environments in which companies operate changes and companies respond by changing their strategies and goals. Those changes drive changes in processes. In an extreme case, a process must be retired and replaced by a new process. In most cases, existing processes are redesigned or gradually improved to conform to new corporate strategies and goals. Environmental changes keep occurring and this cycle keeps going, leading to a continuous business process redesign and improvement effort.