Workflows in UML

Lecture Notes in Computer Science, 2001

If UML activity diagrams are to succeed as a standard in the area of organisational process modeling, they need to compare well to alternative languages such as those provided by commercial Workflow Management Systems. This paper examines the expressiveness ...

Proceedings of the …, 2006

UML is posited as the "swiss army knife" for systems modelling and design activities. It embodies a number of modelling formalisms that have broad applicability in capturing both the static and dynamic aspects of software systems. One area of UML that has received particular attention is that of Activity Diagrams (ADs), which provide a high-level means of modelling dynamic system behaviour. In this paper we examine the suitability of UML 2.0 Activity Diagrams for business process modelling, using the Workflow Patterns as an evaluation framework. The Workflow Patterns are a collection of patterns developed for assessing control-flow, data and resource capabilities in the area of Process Aware Information Systems (PAIS). In doing so, we provide a comprehensive evaluation of the capabilities of UML 2.0 ADs, and their strengths and weaknesses when utilised for business process modelling.

UML and the Unified Process

This chapter proposes an extension to the activity graph of the Unified Modeling Language (UML) to support the Workflow Management Coalition (WfMC) standard. The definition of a business process has been standardized by the WfMC with the purpose of satisfying the need of interaction and connectivity between process definition tools and different workflow systems. Here, the WfMC meta-model is explained. The UML activity diagrams, used for the business process modeling, support less detail than the WfMC standard. In this chapter, an extension of the UML's activity graph metamodel is proposed, and its formalization using the workflow meta-model is defined. The purpose of this chapter is to obtain an extension of UML to support the workflow process definition without changing the standard with the same expressive power as the WfMC. It increments the expressive power of the activity diagrams so that the business processes modeled with the UML notation can be executed by a workflow engine.

2003

ABSTRACT Although UML offers models that can be used to describe business processes, many practitioners nevertheless prefer to employ languages that are specifically designed for this purpose. These business process languages typically provide only a weak integration with software modeling languages such as UML. To enhance the support of software development we therefore suggest to extend UML's activity diagrams with a business process semantics which leads us to Business Process Diagrams (BPDs).

This paper exposes the transformation of UML activity diagrams into Event B for the specification and the verification of parallel and distributed workflow applications. With this transformation, UML models could be verified by verifying derived event B models. The design is initially expressed graphically with UML and translated into Event B. The resulting model is then enriched with invariants describing dynamic properties such as deadlock freeness, livelock freeness and reachability. The approach uses activity diagrams metamodel.

UML and the Unified Process

Today, modeling business processes and modeling software is done using different notations that are designed to fit the special needs of the respective tasks. However, this fact results in a painful methodological gap between business models and software models, which is hard to bridge. This problem becomes even more painful if we try to build software to support certain business models because a smooth transition between the employed notations is usually not supported, or due to methodological problems, impossible. In order to allow for a smoother transition, we propose using Business Process Diagrams (BPDs), which are based on the UML activity diagrams ( in both business and software worlds). We show how to derive BPDs from the well-known business process language of Event-driven Process Chains (EPCs) using Petri nets as a common process meta- model.

2012

In this paper, we propose an UML Activity Diagram (AD) approach based on stepwise refinement technique for modeling and describing workflow applications. Thus, we present a set of UML AD refinement patterns that support the different forms of refining process in a workflow. The workflow application is constructed in a hierarchical fashion. We show that thanks to the hierarchical workflow construction by refinement, a simple view of the workflow is maintained at each level of abstraction. In addition, we provide formal support for building process refinement graphs that are complete, proved correct.

2009

In today's distributed applications, semi automatic and semantic composition of workflows from Grid services is becoming an important challenge. We focus in this paper on how to model and compose interactively workflow applications from Grid services without considering lower level description of the Grid environment. To reach this objective, we propose a Model-Driven Approach for developing such applications based on semantic and syntactic descriptions of services available on the Grid and abstract description provided by UML activity diagram language as well. As there are particular needs for modeling composed workflows interactively from Grid services, we propose to extend the UML activity diagram notation. These extensions deal with additional information allowing an interactive and semi automatic composition of workflows. In addition this specific domain language contains appropriate data to describe matched Grid services that are useful for the execution of the obtained wo...

2001

In this report we define a formal execution semantics for UML activity diagrams that is appropriate for workflow modelling. Our workflow models express software requirements and therefore assume a perfect implementation. In our semantics, software state changes do not take time. It is based upon the Statemate semantics of statecharts, extended with some transactional properties to deal with data manipulation. Our semantics also deals with real time and with multiple state instances. We first give an informal description of our semantics and then formalise this in terms of labelled transition systems. We compare our semantics with other semantics for UML activity diagrams and workflow modelling by analysing the different choices made in those semantics. * Supported by NWO/SION, grant nr. 612-62-02 (DAEMON).

2011

Researchers in software engineering proposed design method for distributed applications to construct a set of communicating system components from a global behavior. The joint behaviors of these components must precisely satisfy the specified global behavior. The next concern is to transform the constructed models of these components into executable business processes by ensuring the exchange of asynchronous messages among the generated business processes. The introduction of Service-Oriented Architecture (SOA) has helped to achieve this goal. SOA provides high flexibility in composing looselyintegrated services that can be used among business domains to carry out business transactions; this composition is known as service orchestration. Moreover, SOA supports Model Driven Architecture (MDA) such that services modeled as UML Activity Diagrams (AD) can be transformed into a set of Business Execution Language (BPEL) processes. Many researchers discussed the transformation of UML AD and the Business Process Modeling Notation (BPMN) into BPEL. However, they did not discuss the practical limitations that some of these transformations impose. This thesis addresses the imitations of the transformation from UML AD to BPEL processes using the IBM Rational Software Architect (RSA). We showed here that the tool is unable to create the correct BPEL artifacts from UML AD components in certain cases, for instance when the behavior includes the alternative for receiving single or concurrent messages, a weak loop, or certain choice activities. Furthermore, we provided novel solutions to the transformations in these cases in order to facilitate the transformation from UML AD to BPEL.