Milan Milanovic

Modeling Flexible Business Processes with Business Rule Patterns

In the paper, we investigate principles for modeling flexible business processes enhanced by business rules. In our work, we start from a set of rule patterns, which are identified in the literature as a mean for increasing flexibility of business processes. The previous work on these patterns only considered the implementation level, but not the implications on the modeling level. Moreover, the potential for business process flexibility have not been fully leveraged due to some limitations in externalization of business logic into business rules. In this work, we report on the experience in modeling the set of rule patterns by using a rule-enhanced business process modeling language (rBPMN), and demonstrate the applicability of our findings on a business process case study.

Towards a Language for Rule-Enhanced Business Process Modeling

Business process modeling is a commonlyused approach in the development of serviceorientedarchitectures. The previous research onthis topic demonstrated that process-oriented modelsmight be too rigid for dynamic adaptations ofthe business logic. Rule-based approaches are consideredan alternative, which offers more flexibilitythanks to the declarative nature of rules and theirunderlying reasoning algorithms. However, modelinga business process through rules is a tediousprocess for developers in terms of the overall businessprocess comprehension. In this paper, we proposea hybrid solution – a modeling language thatintegrates both rule- and process-oriented modelingperspectives. The language (Rule-based BPMN –rBPMN) is based on the integration of the BusinessProcess Modeling Notation with the REWERSERule Markup Language. In this paper, after introducingrBPMN, we report on the experience inmodeling of Service-Oriented Architectures (SOA)from the perspective of message exchange patterns.

Combining Rules and Activities for Modeling Service-Based Business Processes

It is widely acknowledged that business process management would greatly benefit from integration with business rule management. But there is still no established solution to this integration problem, and the leading business process modeling language, BPMN, does not provide any explicit support for rules. In this paper, we are going to investigate the extension of BPMN by adding rules as a modeling concept in the form of a new gateway type, using the principles of model-driven engineering. The integration will be done on the level of the metamodels of the involved languages, resulting in a new rule-based process modeling language called rBPMN (rule-based BPMN).

Towards Sharing Rules Between OWL/SWRL and UML/OCL

The paper presents a metamodel-driven model transformation approach to interchanging rules between the Semantic Web Rule Language along with the Web Ontology Language (OWL/SWRL) and Object Constraint Language (OCL) along with UML (UML/OCL). The solution is based on the REWERSE Rule Markup Language (R2ML), a MOF-defined general rule language, as a pivotal metamodel and the bidirectional transformations between OWL/SWRL and R2ML and between UML/OCL and R2ML. Besides describing mapping rules between three rule languages, the paper proposes the implementation by using ATLAS Transformation language (ATL) and describes the whole transformation process involving several MOF-based metamodels, XML schemas, EBNF grammars.

Sharing OCL Constraints by Using Web Rules

This paper presents an MDE-based approach to interchanging rules between the Object Constraint Language (OCL) and REWERSE I1 Rule Markup Language (R2ML). The R2ML tends to be a standard rule markup language by following up the W3C initiative for Rule Interchange Format (RIF). The main benefit of this approach is that the transformations between languages are completely based on the languages’ abstract syntax (i.e., metamodels) and in this way we keep the focus on the language concepts rather than on technical issues caused by different concrete syntax. In the current implementation, we have supported translation of the OCL invariants into the R2ML integrity rules. While most of the OCL expression could be represented in the R2ML and other rule languages, we have also identified that collection operators could only be partially supported in other rule languages (e.g., SWRL).

Modeling service orchestrations with a rule-enhanced business process language

Business process modeling has been a promising direction in developing service compositions, including both service orchestrations and choreographies. This paper fully focuses on the problem of modeling service orchestrations. Despite many promising aspects of using business process modeling (BPM) languages for modeling service orchestrations, this paper aims to demonstrate that: i) best practices (workflow patters) for control flows (primary concern of service orchestrations) are not fully covered in present languages; ii) complete service compositions cannot be completely generated from business process models; and iii) BPM languages have limited support for representing logical expressions, business vocabularies, and business rules, which severely limits their flexibility and expressivity. To address these challenges, we have integrated business rule modeling constructs of the REWERSE Rule Markup Language (R2ML) with the Business Process Modeling Notation (BPMN), resulting in our rBPMN proposal.

Model-Driven Engineering of a General Policy Modeling Language

Despite many efforts in developing policy languages which work in different logical domains and with various reasoning engines, there has been limited attention paid to bringing policy definition, design, and integration into the realm of the mainstream software development process. There seems to be a lack of appropriate software development tooling that can allow for easy representation and integration of policies with other pieces of software at the design time. This paper presents a general policy modeling language (GPML), following the rationale of model driven engineering (MDE), as a means to design policies and integrate them to the software development process. We describe the logical foundation and the modeling rationale behind GPML and show how it is adjustable to the existing policy languages.

Rule-Enhanced Business Process Modeling Language for Service Choreographies

To address problem of modeling service choreographies, the paper tackles the following challenges of the state of the art in choreography modeling: i) choreography models are not well-connected with the underlying business vocabulary models. ii) there is limited support for decoupling parts of business logic from complete choreography models. This reduces dynamic changes of choreographies; iii) choreography models contain redundant elements of shared business logic, which might lead to an inconsistent implementation and incompatible behavior. Our proposal --- rBPMN --- is an extension of a business process modeling language with rule and choreography modeling support. rBPMN is defined by weaving the metamodels of the Business Process Modeling Notation (BPMN) and REWERSE Rule Markup Language (R2ML).

Modeling Service Choreographies with Rule-Enhanced Business Processes

The research community has so far mainly focused on the problem of modeling of service orchestrations in the domain of service composition, while modeling of service choreographies has attracted less attention. The following challenges in choreography modeling are tackled in this paper: i) choreography models are not well-connected with the underlying business vocabulary models. ii) there is limited support for decoupling parts of business logic from complete choreography models. This reduces dynamic changes of choreographies, iii) choreography models contain redundant elements of shared business logic, which might lead to an inconsistent implementation and incompatible behavior. Our proposal – rBPMN – is an extension of a business process modeling language with rule and choreography modeling support. rBPMN is defined by weaving the metamodels of the Business Process Modeling Notation and REWERSE Rule Markup Language. To evaluate our proposal, we use service-interaction patterns and compare our approach with related solutions.

Bridging concrete and abstract syntax of web rule languages

This paper proposes a solution for bridging abstract and concrete syntax of a Web rule language by using model transformations. Current specifications of Web rule languages such as Semantic Web Rule Language (SWRL) define its abstract syntax (e.g., EBNF notation) and concrete syntax (e.g., XML schema) separately. Although the recent research in the area of Model-Driven Engineering demonstrates that such a separation of two types of syntax is a good practice (due to the complexity of languages), one should also have tools that check validity of rules written in a concrete syntax with respect to the abstract syntax of the rule language. In this study, we use analyze the REWERSE I1 Rule Markup Language (R2ML) whose abstract syntax is defined by using metamodeling, while its textual concrete syntax is defined by using XML schema. We bridge this gap by a bi-directional transformation defined in a model transformation language (i.e., ATL).