Oana Nicolae

Extending discrete event simulation by adding an activity concept for business process modeling and simulation

We show how a basic discrete event simulation language can be enabled for business process modeling and simulation by adding an activity construct. While activities are often not considered at all or not treated in a conceptually satisfactory way in the discrete event simulation literature, the great majority of business process modeling languages are based on an activity construct. However, unlike a simulation language, the predominant business process modeling languages, including UML Activity Diagrams and the Business Process Modeling Notation (BPMN), are not executable. So, the challenge for business process modeling is to define an executable semantics for activities, while the challenge for discrete event simulation is to find a way how to introduce an activity construct on top of the basic discrete event simulation concepts of objects and events. The main idea is to define an activity as a complex event having a start event and an end event. This idea is well-known from the business process modeling literature, e.g. from the Business Process Definition Metamodel (Bock 2008), but it has also been used in a rudimentary way in some discrete event simulation approaches, e.g. in (Fishman 2001). Our research contribution consists of two achievements: 1) we define a conceptual model of activities for discrete event simulation and implement it in our ER/AOR simulation language; 2) we show how to use BPMN for the purpose of simulation modeling.

Towards a BPMN Semantics Using UML Models

Standardization initiatives on the field claim to be a consequence of the long expected maturity of Business Process Management (i.e. BPM) market and they try to impose a precise semantics for an unique and common understanding. Standard specifications provide usually less or more informal description of the involved languages. Open-source/proprietary tools often do not succeed to generate an executable code by following only the specifications requirements. Therefore, they could not make a clear distinction between the specification technology they implement, and their own requirements vis-a-vis the enactment. For the sake of a common understanding of the concepts, and for future improvements of the languages, a high-level modelling using UML is needed. The aim of the paper is to discuss Service Interaction Patterns directly supported by BPMN 1.1, and to use UML models in order to describe the abstract syntax of the involved concepts. An informal correspondence with WS-BPEL 2.0 elements is provided, together with their associated UML models description. As a consequence of the limited support for Service Interaction Patterns, another purpose of the paper is to discuss the directions in which the BPMN Standard seems to evolve, in order to suit the industry demands.

Modeling and Simulating Organisations

The paper provides a survey comprising meaningful organisational approaches to Multi-Agent-Systems (MAS) that exist in the computational theory field. The organisational concepts are collected and represented as a metamodel of some commonly agreed organisational ontology of human systems. Next, this metamodel - a proposal for the extension of the Agent-Object-Relationship (AOR) simulation language with organisational constructs - will be analysed and improved by taking into consideration the organisational approaches originating from the fields of social sciences. Our account is exemplified by a case study where we model an academic environment with the help of the organisation-oriented concepts defined by the AOR simulation language.

Towards an Executable Semantics for Activities Using Discrete Event Simulation

The paper aims at answering to the challenge of defining an executable semantics for the activity concept, in the context of Business Process Modeling and Simulation. The main purpose for introducing an activity concept on top of the basic Discrete Event Simulation concepts of objects and events is to define an activity as consisting of a start event and an end event. This idea is well-known from the business process modeling literature, e.g. from BPDM. We also expect the adoption of this concept view for the BPMN activity in the future BPMN 2.0 Specification. A case study is used throughout the paper to illustrate the concepts and to present our results.

Verbalising R2ML Rules into SBVR

Nowadays, business rules receive a lot of attention from both industry and academia, as they are considered the ideal vehicle for capturing business logic. The purpose of our paper is to raise the level of business logic abstraction with the help of existing, mature enough, R2ML language, in order to obtain higher semantic representations of rules and their basic constructs i.e. SBVR. Our paper focuses on the informal translation from R2ML derivation and integrity rules, into SBVR structured English in order to provide means for business rules validation and authorization. SBVR semantic formulations of R2ML rule sand their basic atoms are also described and exemplified, as they are the unique construct of SBVR standard, that captures and structures the meaning of rules to enable further translations into executable rule languages/engines, following MDA abstract levels of rule modeling.

Sharing Rules between JBoss and Jena

The actual rule based implementations point to different rule target platforms and languages (object oriented rule languages, semantic Web rule languages, artificial intelligence rule languages) in a business landscape dominated by a limited number of tool vendors as well as competitive open-source platforms and rule interoperability initiatives. This work provides a description of business rules translation from JBoss-Rules - an object oriented rule-system, to Jena Rules - a semantic Web rule-system, via an interchange language. It focuses on the general lines of the JBoss- RZML-Jena translation and to outline the limitations and on the correctness of the proposed interchange.

On Interchange between JBoss Rules and Jess

There is a growing demand for research to provide insights into challenges, and solutions based on business rules related to target PSM (Platform Specific Model in OMG’s MDA terms - Implementation Model). As an answer to this needs, this paper argues on the relevance of business rules target platforms for the actual IT and business context, emphazising the important role of business rules inter-operability initiatives, so that rule-system developers can do their work without concern about a vendor-specific format and in particular without concern about the compatibility between the technologies. This paper provides a description of the business rules translation from a particular rule-system such as JBoss Rules to another rule-system representation as Jess, using R2ML as interchange language.

Towards a conceptual model and framework for management games

Management games have a long history in management and social science education, and a large number of such games has been developed and is being used in university education and in professional training. With the increasing use of computers in recent decades, most of them have been developed in computerized form. However, typically, these games are being developed in isolation, without (re-)using any general model, or methodology, or simulation engineering framework. In this paper we propose a basic conceptual model for business management games based on the classical Lemonade Stand Game and we show how to construct incremental extensions of this model and how to implement them as web-based simulations using standard web technologies.

Towards simulation of organizational norms

Unlike social norms, which are the unplanned, unexpected result of the interactions among human individuals, organizational norms are stipulated by the organization with the purpose of constraining the behavior of organizational actors in the context of business processes. We propose a simple conceptual model of organizations and organizational norms as an extension of the metamodel of the Agent-Object-Relationship (AOR) simulation language. In our approach an organization is modeled as an institutional agent with organizational units and human actors as subagents that participate in business processes involving other agents, which are possibly affiliated with other organizations. For simplicity, we consider only the most basic form of behavior, which is reactive behavior described in the form of reaction rules, and the most basic types of organizational norms, which are rights and duties defined for organizational positions and roles.

Web Services for Search Integration

This paper is closely related to the problem of finding elements having certain positions resulted after merging between two or more result sets. The problem is encountered frequently nowadays, a typical situation being a business distributed environment i.e. SOA approach, where as a direct consequence of aWeb search, each participating entity will provide a result set. The focus of paper is to describe a web service for optimally returning the k-th element obtained from joining web search services results into a composite result [3]. We introduce an optimized algorithm for solving the problem, based on a divide-and-conquer technique and we discuss, by means of examples, its performances as related to other approaches.