Model-driven design, simulation and implementation of service compositions in COSMO

The success of software development projects to a large extent depends on the quality of the models that are produced in the development process, which in turn depends on the conceptual and practical support that is available for modelling, design and analysis. This paper focuses on model-driven support for service-oriented software development. In particular, it addresses how services and compositions of services can be designed, simulated and implemented. The support presented is part of a larger framework, called COSMO (COnceptual Service MOdelling). Whereas in previous work we reported on the conceptual support provided by COSMO, in this paper we proceed with a discussion of the practical support that has been developed. We show how reference models (model types) and guidelines (design steps) can be iteratively applied to design service compositions at a platform independent level and discuss what tool support is available for the design and analysis during this phase. Next, we present some techniques to transform a platform independent service composition model to an implementation in terms of BPEL and WSDL. We use the mediation scenario of the SWS challenge (concerning the establishment of a purchase order between two companies) to illustrate our application of the COSMO framework

Modeling Service Choreographies with Rule-enhanced Business Processes

The participation at EDOC 2010 was overwhelming in every positive sense, and I am very thankful to the committee for this award. Our presentation was received highly positive and triggered several questions. The questions were mainly about the relations of our work with the use of ontology and vocabulary representation languages, and our plans for developing executable models rather than generating code from models. In fact, this was already in line with our previous plans and research directions. Some of these discussions even continued during the following days. In particular, we had plans for two concrete collaborations. One is related to the development of a formal semantics of the rBPMN languages by using process algebra, that is, by using the mCRL2 language in particular. Moreover, we also created a common plan for integration of semi-structured English language for defining business rules and vocabularies. This will also allow us to have a more effective way to capture rules in rBPMN process models. Moreover, our presentation of the rBPMN editor, as an practical implementation tool for the work with the rBPMN language received a special attention, and several researchers have already approached us to establish research collaboration and/or to use our tool, which is now publically available. The overall experience was also extremely valuable. The program of the conference covered nearly all of the diverse topics in enterprise computing. That is, the selected papers cover engineering aspects in many phases of development life cycle of enterprise systems, especially those designed for distributed environments. I have also delivered a keynote at the VORTE 2010 workshop with the audience with was the largest of all workshop keynotes at the conference. The participants very positively received my insights. In a very interactive session, we discussed some of the main research challenges important for better integration of business rules and business process modeling languages.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

A Requirements-Led Approach for Specifying QoS-Aware Service Choreographies: An Experience Report.

[Context and motivation] Choreographies are a form of service composition in which partner services interact in a global scenario without a single point of control. The absence of an explicitly specified orchestration requires changes to requirements practices to recognize the need to optimize software services choreography and monitoring for satisfaction with system requirements. [Question/problem] We developed a requirements-led approach that aims to provide tools and processes to transform requirements expressed on service-based systems to QoS-aware choreography specifications. [Principal ideas/results] The approach is used by domain experts to specify natural language requirements on a service-based system, and by choreography designers to adapt their models to satisfy requirements more effectively. Non-functional requirements are mapped to BPMN choreography diagrams as quality properties, using the Q4BPMN notation, that support analysis and monitoring facilities. [Contribution] We report the new integrated approach and provide lessons learned from applying it to a real-world example of dynamic taxi management

Data perspective in process choreographies : modeling and execution

Process choreographies - communication between different organizations to exchange information - is part of daily business. While the correct ordering of exchanged messages can be modeled and enacted with current choreography techniques, no approach exists to describe the data perspective for a successful process choreography. In this paper, we describe an entirely model-driven approach for BPMN, the industry standard, to include the data perspective while maintaining control flow aspects by utilizing a recent concept to enact data dependencies in internal processes. This work provides a modeling guideline with the require artifacts and their operational semantics to allow automatic choreography enactment covering data retrieval, transformation, and correlation. We show applicability of our approach by an implementation for the Camunda BPM platform, a java-based process engine, and validate it with the service interaction patterns. Keywords: Process Modeling, Data Modeling, Process Choreographies, Process Enactment, BPMN, SQ

Extending a Business Process Modeling Language for Domain-Specific Adaptation in Healthcare

It is often required to provide a modeling language that enables the representation of domain-specific problems and concepts. Domain-specific modeling approaches can be applied for that. However, these approaches usually suffer from low dissemination, missing tool support and high design costs. Thus, it might be more reasonable to adapt and extend common standard modeling languages. This research article presents an extension of the common process modeling language BPMN for modeling clinical pathways in the healthcare sector. The extension is designed methodically by application of the extension design method of Stroppi et al. (2011), which was extended regarding to a deeper domain analysis. The domain analysis considers the design of a domain ontology, requirements analysis as well as an equivalence check between domain concept and BPMN concepts. Finally, the evolved extension is compared with the CPmod modeling language of Burwitz et al. (2013) in order to discuss strengths and limitations

Data-Aware Interaction in Distributed and Collaborative Workflows: Modeling, Semantics, Correctness

IT support for distributed and collaborative workflows and related interactions between business partners is becoming increasingly important. For modeling such partner interactions as flow of message exchanges, different top-down approaches, covered under the term interaction modeling, are provided. Like for workflow models, correctness constitutes a fundamental challenge for interaction models as well; e.g., to ensure the boundedness and absence of deadlocks and lifelocks. Due to their distributed execution, in addition, interaction models should be message-deterministic and realizable, i.e., the same conversation (i.e. sequence of messages) should always lead to the same result, and it should be ensured that partners always have enough information about the messages they must or may send in a given context. So far, most existing approaches have addressed correctness of interaction models without explicitly considering the data exchanged through messages and used for routing decisions. However, data support is crucial for collaborative workflows and interaction models respectively. This paper therefore enriches interaction models with the data perspective. In particular, it defines the behavior of data-aware interaction models based on Data-Aware Interaction Nets, which use elements of both Interaction Petri Nets and Workflow Nets with Data. Finally, formal correctness criteria for Data-Aware Interaction Nets are derived, guaranteeing the boundedness and absence of deadlocks and lifelocks, and ensuring message-determinism as well as realizability

Correctness of services and their composition

We study correctness of services and their composition and investigate how the design of correct service compositions can be systematically supported. We thereby focus on the communication protocol of the service and approach these questions using formal methods and make contributions to three scenarios of SOC.Wir studieren die Korrektheit von Services und Servicekompositionen und untersuchen, wie der Entwurf von korrekten Servicekompositionen systematisch unterstützt werden kann. Wir legen dabei den Fokus auf das Kommunikationsprotokoll der Services. Mithilfe von formalen Methoden tragen wir zu drei Szenarien von SOC bei

Declarative process modeling in BPMN

Traditional business process modeling notations, including the standard Business Process Model and Notation (BPMN), rely on an imperative paradigm wherein the process model captures all allowed activity flows. In other words, every flow that is not specified is implicitly disallowed. In the past decade, several researchers have exposed the limitations of this paradigm in the context of business processes with high variability. As an alternative, declarative process modeling notations have been proposed (e.g., Declare). These notations allow modelers to capture constraints on the allowed activity flows, meaning that all flows are allowed provided that they do not violate the specified constraints. Recently, it has been recognized that the boundary between imperative and declarative process modeling is not crisp. Instead, mixtures of declarative and imperative process modeling styles are sometimes preferable, leading to proposals for hybrid process modeling notations. These developments raise the question of whether completely new notations are needed to support hybrid process modeling. This paper answers this question negatively. The paper presents a conservative extension of BPMN for declarative process modeling, namely BPMN-D, and shows that Declare models can be transformed into readable BPMN-D models. © Springer International Publishing Switzerland 2015

A Formal Framework for Data-Aware Process Interaction Models

IT support for distributed and collaborative workflows as well as related interactions between business partners are becoming increasingly important. For modeling such partner interactions as flow of message exchanges, different topdown approaches, covered under the term interaction modeling, are provided. Like for workflow models, correctness constitutes a fundamental challenge for interaction models; e.g., to ensure the boundedness and absence of deadlocks and lifelocks. Due to their distributed execution, in addition, interaction models should be message-deterministic and realizable, i.e., the same conversation (i.e. sequence of messages) should always lead to the same result, and it should be ensured that partners always have enough information about the messages they must or may send in a given context. So far, most existing approaches have addressed correctness of interaction models without explicitly considering the data exchanged through messages and used for routing decisions. However, data support is crucial for collaborative workflows and interaction models respectively. This technical report enriches interaction models with the data perspective. In particular, it defines the behavior of data-aware interaction models based on Data- Aware Interaction Nets, which use elements of both Interaction Petri Nets and Workflow Nets with Data. Finally, formal correctness criteria for Data-Aware Interaction Nets are derived, guaranteeing the boundedness and absence of deadlocks and lifelocks, and ensuring message-determinism as well as realizability