Ahm Arthur ter Hofstede

Pattern-based analysis of the control-flow perspective of UML activity diagrams

The Unified Modelling Language (UML) is a well-known family of notations for software modelling. Recently, a new version of UML has been released. In this paper we examine the Activity Diagrams notation of this latest version of UML in terms of a collection of patterns developed for assessing control-flow capabilities of languages used in the area of process-aware information systems. The purpose of this analysis is to assess relative strengths and weaknesses of control-flow specification in Activity Diagrams and to identify ways of addressing potential deficiencies. In addition, the pattern-based analysis will yield typical solutions to practical process modelling problems and expose some of the ambiguities in the current UML 2.0 specification [9].

Patterns-based evaluation of open source BPM systems: The cases of jBPM, OpenWFE, and Enhydra Shark

In keeping with the proliferation of free software development initiatives and the increased interest in the business process management domain, many open source workflow and business process management systems have appeared during the last few years and are now under active development. This upsurge gives rise to two important questions: What are the capabilities of these systems? and How do they compare to each other and to their closed source counterparts? In other words: What is the state-of-the-art in the area?. To gain an insight into these questions, we have conducted an in-depth analysis of three of the major open source workflow management systems - jBPM, OpenWFE, and Enhydra Shark, the results of which are reported here. This analysis is based on the workflow patterns framework and provides a continuation of the series of evaluations performed using the same framework on closed source systems, business process modelling languages, and web-service composition standards. The results from evaluations of the three open source systems are compared with each other and also with the results from evaluations of three representative closed source systems: Staffware, WebSphere MQ, and Oracle BPEL PM. The overall conclusion is that open source systems are targeted more toward developers rather than business analysts. They generally provide less support for the patterns than closed source systems, particularly with respect to the resource perspective, i.e. the various ways in which work is distributed amongst business users and managed through to completion.

Root cause analysis with enriched process logs

In the field of process mining, the use of event logs for the purpose of root cause analysis is increasingly studied. In such an analysis, the availability of attributes/features that may explain the root cause of some phenomena is crucial. Currently, the process of obtaining these attributes from raw event logs is performed more or less on a case-by-case basis: there is still a lack of generalized systematic approach that captures this process. This paper proposes a systematic approach to enrich and transform event logs in order to obtain the required attributes for root cause analysis using classical data mining techniques, the classification techniques. This approach is formalized and its applicability has been validated using both self-generated and publicly-available logs.

Visual Support for Work Assignment in Process-Aware Information Systems

Process-aware information systems ranging from generic workflow systems to dedicated enterprise information systems use work liststo offer so-called work itemsto users. The work list handlers typically show a sorted list of work items comparable to the way that e-mails are presented in most e-mail programs. Since the work list handler is the dominant interface between the system and its users, it is worthwhile to provide a more advanced graphical interface that uses context information about work items and users. This paper uses the map metaphor to visualise work items and resources (e.g., users) in a sophisticated manner. Moreover, based on distance notions work items are visualised differently. For example, urgent work items of a type that suits the user are highlighted. The underlying map and distance notions may be of a geographical nature (e.g., a map of a city of office building), but may also be based on the process design, organisational structures, social networks, due dates, calenders, etc. The approach presented in this paper is supported by a visualisation framework implemented in the context of YAWL. The framework is set up in such a way that it can easily be combined with other workflow systems.

Open Source Software for Workflow Management: The Case of YAWL

Workflow management systems support business process design, execution, and analysis. They must guarantee that work is conducted at the right time-and by the right person or software application-through the execution of a workflow process model. YAWL (Yet Another Workflow Language) was developed in 2002 to show that comprehensive support for workflow patterns is achievable. Soon after the lan guages inception, a prototype system was built to show that system support for such a complex language was possible. From that initial prototype, YAWL has grown into a full-fledged open source workflow management system and support environment.

Designing a Workflow System Using Coloured Petri Nets

Traditional workflow systems focus on providing support for the control-flow perspective of a business process, with other aspects such as data management and work distribution receiving markedly less attention. A guide to desirable workflow characteristics is provided by the well-known workflow patterns which are derived from a comprehensive survey of contemporary tools and modelling formalisms. In this paper we describe the approach taken to designing the newYAWL workflow system, an offering that aims to provide comprehensive support for the control-flow, data and resource perspectives based on the workflow patterns. The semantics of the newYAWL workflow language are based on Coloured Petri Nets thus facilitating the direct enactment and analysis of processes described in terms of newYAWL language constructs. As part of this discussion, we explain how the operational semantics for each of the language elements are embodied in the newYAWL system and indicate the facilities required to support them in an operational environment. We also review the experiences associated with developing a complete operational design for an offering of this scale using formal techniques.

Surmounting BPM challenges: the YAWL story

AbstractThe field of Business Process Management (BPM) has evolved considerably over the past decade. Manyn proposals for business process modelling and/or execution have emerged and some of these have faded inton oblivion again. The Workflow Patterns Initiative aimed at achieving axa0more structured approach ton language comparison and development. The patterns that were distilled served as the basis for YAWL (Yetn Another Workflow Language). In this paper YAWL is positioned with respect to historical developments inn BPM and current challenges in the field.n

Event interval analysis

Through the application of process mining, valuable evidence-based insights can be obtained about business processes in organisations. As a result, the field has seen an increased uptake in recent years as evidenced by success stories and increased tool support. However, despite this impact, current performance analysis capabilities remain somewhat limited in the context of information-poor event logs. For example, natural daily and weekly patterns are not considered but they are vital for understanding the performance of processes and resources. In this paper, a new framework for analysing event logs is defined. Our framework is based on the concept of event interval. The framework allows for a systematic approach to sophisticated performance-related analysis beyond the capabilities of existing log-based analysis techniques, even with information-poor event logs. The paper formalises a range of event interval types and then presents an implementation as well as an evaluation of the proposed approach. A new framework is proposed to analyse process performance via information-poor log.It is built upon a new concept of event interval to systematically extract rich insights.It has been implemented as a plug-in tool within an open-source environment.It has been validated using a real log from an Australian insurance organisation.It has been applied to gain interesting performance insights from the industry log.

newYAWL: Towards Workflow 2.0

The field of workflow technology has burgeoned in recent years providing a variety of means of automating business processes. It is a great source of opportunity for organisations seeking to streamline and optimise their operations. Despite these advantages however, the current generation of workflow technologies are subject to a variety of criticisms, in terms of their restricted view of what comprises a business process, their imprecise definition and their general inflexibility. As a remedy to these potential difficulties, in this paper we propose a series of development goals for the next generation of workflow technology. We also present new YAWL, a formally defined, multi-perspective reference language for workflow systems.

Soundness of Workflow Nets with Reset Arcs

Petri nets are often used to model and analyze workflows. Many workflow languages have been mapped onto Petri nets in order to provide formal semantics or to verify correctness properties. Typically, the so-called Workflow nets are used to model and analyze workflows and variants of the classical soundness property are used as a correctness notion. Since many workflow languages have cancelation features, a mapping to workflow nets is not always possible. Therefore, it is interesting to consider workflow nets with reset arcs. Unfortunately, soundness is undecidable for workflow nets with reset arcs. In this paper, we provide a proof and insights into the theoretical limits of workflow verification.