Chun Ouyang

From business process models to process-oriented software systems

Several methods for enterprise systems analysis rely on flow-oriented representations of business operations, otherwise known as business process models. The Business Process Modeling Notation (BPMN) is a standard for capturing such models. BPMN models facilitate communication between domain experts and analysts and provide input to software development projects. Meanwhile, there is an emergence of methods for enterprise software development that rely on detailed process definitions that are executed by process engines. These process definitions refine their counterpart BPMN models by introducing data manipulation, application binding, and other implementation details. The de facto standard for defining executable processes is the Business Process Execution Language (BPEL). Accordingly, a standards-based method for developing process-oriented systems is to start with BPMN models and to translate these models into BPEL definitions for subsequent refinement. However, instrumenting this method is challenging because BPMN models and BPEL definitions are structurally very different. Existing techniques for translating BPMN to BPEL only work for limited classes of BPMN models. This article proposes a translation technique that does not impose structural restrictions on the source BPMN model. At the same time, the technique emphasizes the generation of readable (block-structured) BPEL code. An empirical evaluation conducted over a large collection of process models shows that the resulting BPEL definitions are largely block-structured. Beyond its direct relevance in the context of BPMN and BPEL, the technique presented in this article addresses issues that arise when translating from graph-oriented to block-structure flow definition languages.

WofBPEL: a tool for automated analysis of BPEL processes

The Business Process Execution Language for Web Service, known as BPEL4WS, more recently as WS-BPEL (or BPEL for short) [1], is a process definition language geared towards Service-Oriented Computing (SOC) and layered on top of the Web services technology stack. In BPEL, the logic of the interactions between a given service and its environment is described as a composition of communication actions. These communication actions are interrelated by control-flow dependencies expressed through constructs close to those found in workflow definition languages. In particular, BPEL incorporates two sophisticated branching and synchronisation constructs, namely “control links” and “join conditions”, which can be found in a class of workflow models known as synchronising workflows formalised in terms of Petri nets in [3].

Translating standard process models to BPEL

Standardisation of languages in the field of business process management has long been an elusive goal. Recently though, consensus has built around one process implementation language, namely BPEL, and two fundamentally similar process modelling notations, namely UML Activity Diagram (UML AD) and BPMN. This paper presents a technique for generating BPEL code from process models expressed in a core subset of BPMN and UML AD. This model-to-code translation is a necessary ingredient to the emergence of model-driven business process development environments based on these standards. The proposed translation has been implemented as an open source tool.

APQL : a process-model query language

As business process management technology matures, organisations acquire more and more business process models. The management of the resulting collections of process models poses real challenges. One of these challenges concerns model retrieval where support should be provided for the formulation and efficient execution of business process model queries. As queries based on only structural information cannot deal with all querying requirements in practice, there should be support for queries that require knowledge of process model semantics. In this paper we formally define a process model query language that is based on semantic relationships between tasks in process models and is independent of any particular process modelling notation.

The Service Adaptation Machine

The reuse of software services often requires the introduction of adapters. In the case of coarse-grained services, and especially services that engage in long-running conversations, these adapters must deal not only with mismatches at the level of individual interactions, but also across interdependent interactions. Existing techniques support the synthesis of adapters at design-time by comparing pairs of service interfaces. However, these techniques only work under certain restrictions. This paper explores a runtime approach to service interface adaptation. The paper proposes an adaptation machine that sits between pairs of services and manipulates the exchanged messages according to a repository of mapping rules. The paper formulates an operational semantics for the adaptation machine, including algorithms to compute rule firing sequences and criteria for detecting deadlocks and information loss. The adaptation machine has been implemented as a prototype and tested on common business processes.

Process Mining for Clinical Processes: A Comparative Analysis of Four Australian Hospitals

Business process analysis and process mining, particularly within the health care domain, remain under-utilized. Applied research that employs such techniques to routinely collected health care data enables stakeholders to empirically investigate care as it is delivered by different health providers. However, cross-organizational mining and the comparative analysis of processes present a set of unique challenges in terms of ensuring population and activity comparability, visualizing the mined models, and interpreting the results. Without addressing these issues, health providers will find it difficult to use process mining insights, and the potential benefits of evidence-based process improvement within health will remain unrealized. In this article, we present a brief introduction on the nature of health care processes, a review of process mining in health literature, and a case study conducted to explore and learn how health care data and cross-organizational comparisons with process-mining techniques may be approached. The case study applies process-mining techniques to administrative and clinical data for patients who present with chest pain symptoms at one of four public hospitals in South Australia. We demonstrate an approach that provides detailed insights into clinical (quality of patient health) and fiscal (hospital budget) pressures in the delivery of health care. We conclude by discussing the key lessons learned from our experience in conducting business process analysis and process mining based on the data from four different hospitals.

Dynamic Weaving in Aspect Oriented Business Process Management

Reducing complexity in Information Systems is an important topic in both research and industry. One strategy to deal with complexity is separation of concerns, which results in less complex, easily maintainable and more reusable systems. Separation of concerns can be addressed through the Aspect Oriented paradigm. Although this paradigm has been well researched in programming, it is still at the preliminary stage in the area of Business Process Management. While some efforts have been made to extend business process modelling with aspect oriented capability, it has not yet been investigated how aspect oriented business process models should be executed at runtime. In this paper, we propose a generic solution to support execution of aspect oriented business process models based on the principle behind dynamic weaving of aspects. This solution is formally specified using Coloured Petri Nets. The resulting formal specification serves as the blueprint to the implementation of a service module in the framework of a state-of-the-art Business Process Management System. Using this developed artefact, a case study is performed in which two simplified processes from real business in the domain of banking are modelled and executed in an aspect oriented manner. Through this case study, we also demonstrate that adoption of aspect oriented modularization increases the reusability while reducing the complexity of business process models in practice.

Aspect Oriented Business Process Modelling with Precedence

Complexity is a major concern which is aimed to be overcome by people through modelling. One way of reducing complexity is separation of concerns, e.g. separation of business process from applications. One sort of concerns are cross-cutting concerns i.e. concerns which are scattered and tangled through one or several models. In business process management, examples of such concerns are security and privacy policies. To deal with these cross-cutting concerns, the aspect orientated approach was introduced in the software development area and recently also in the business process management area. The work presented in this paper elaborates on aspect oriented process modelling. It extends earlier work by defining a mechanism for capturing multiple concerns and specifying a precedence order according to which they should be handled in a process. A formal syntax of the notation is presented precisely capturing the extended concepts and mechanisms. Finally, the relevance of the approach is demonstrated through a case study.

Data and process requirements for product recall coordination

When an organisation becomes aware that one of its products may pose a safety risk to customers, it must take appropriate action as soon as possible or it can be held liable. The ability to automatically trace potentially dangerous goods through the supply chain would thus help organisations fulfil their legal obligations in a timely and effective manner. Furthermore, product recall legislation requires manufacturers to separately notify various government agencies, the health department and the public about recall incidents. This duplication of effort and paperwork can introduce errors and data inconsistencies. In this paper, we examine traceability and notification requirements in the product recall domain from two perspectives: the activities carried out during the manufacturing and recall processes and the data collected during the enactment of these processes. We then propose a workflow-based coordination framework to support these data and process requirements.

A Formal Service Specification for the Internet Open Trading Protocol

This paper presents our service specification for the Internet Open Trading Protocol (IOTP) developed using Coloured Petri Nets. To handle IOTPs complexity, we apply a protocol engineering methodology based on Open Systems Interconnection (OSI) principles consisting of five iterative steps: the definition of service primitives and parameters; the creation of an automaton specifying the local service language for each of the four trading roles of IOTP; the development of a CPN model synthesizing the local automata into a specification of the global service capturing the correlations between the service primitives at the distributed trading roles; the generation of the occurrence graph representing the global service language; and lastly a new step, language comparison to ensure the consistency between the specifications of the local service language and the global service language. The outcome is a proposed formal service specification for IOTP.