Note:  Accepted by: Hans Weigand and Paul Johannesson
Abstract: The presented paper proposes a state machine of REA (Resource–Event–Agent) model. This model constitutes a fundamental building block for value modeling applications. Contrary to other approaches to this issue, the paper proposes the state machine “inside” the REA model utilizing the DEMO (Design & Engineering Methodology for Organizations) generic approach and its other features. This means that the states of the REA model itself are taken into consideration. One of the advantages of DEMO is its perception of an enterprise as a social system, of which the elements are human subjects that are in their roles of social individuals. It is obvious that human subjects have appropriate authority and bear the corresponding responsibility. From a wider perspective, the REA model can be considered a social system because the fundamental elements of the model are human subjects (economic agents). For this reason, the REA model and its relationships can be viewed from the DEMO transaction pattern perspective despite possible differences in modeling. The core relationships of the REA model acquire a new meaning and bearing. The result of this approach is the introduction of a clear and unambiguous state machine. This approach inherently integrates the current, past and future event into one structure (transaction) and simplifies the traditional REA distinction between current and past events and future events modeled by commitments. The paper also analyzes the phases of a business transaction to prove that the proposed solution is in compliance with the business transaction declaration.
Keywords: State machine, value modeling, DEMO, REA model, enterprise ontology