Arthur H. M. ter Hofstede

Business process management: a survey

Business Process Management (BPM) includes methods, techniques, and tools to support the design, enactment, management, and analysis of operational business processes. It can be considered as an extension of classical Workflow Management (WFM) systems and approaches. Although the practical relevance of BPM is undisputed, a clear definition of BPM and related acronyms such as BAM, BPA, and STP are missing. Moreover, a clear scientific foundation is missing. In this paper, we try to demystify the acronyms in this domain, describe the state-of-the-art technology, and argue that BPM could benefit from formal methods/languages (cf. Petri nets, process algebras, etc.).

Process Mining Manifesto

Process mining techniques are able to extract knowledge from event logs commonly available in today’s information systems. These techniques provide new means to discover, monitor, and improve processes in a variety of application domains. There are two main drivers for the growing interest in process mining. On the one hand, more and more events are being recorded, thus, providing detailed information about the history of processes. On the other hand, there is a need to improve and support business processes in competitive and rapidly changing environments. This manifesto is created by the IEEE Task Force on Process Mining and aims to promote the topic of process mining. Moreover, by defining a set of guiding principles and listing important challenges, this manifesto hopes to serve as a guide for software developers, scientists, consultants, business managers, and end-users. The goal is to increase the maturity of process mining as a new tool to improve the (re)design, control, and support of operational business processes.

Workflow resource patterns: identification, representation and tool support

In the main, the attention of workflow researchers and workflow developers has focussed on the process perspective, i.e., control-flow. As a result, issues associated with the resource perspective, i.e., the people and machines actually doing the work, have been largely neglected. Although the process perspective is of most significance, appropriate consideration of the resource perspective is essential for successful implementation of workflow technology. Previous work has identified recurring, generic constructs in the control-flow and data perspectives, and presented them in the form of control-flow and data patterns. The next logical step is to describe workflow resource patterns that capture the various ways in which resources are represented and utilised in workflows. These patterns include a number of distinct groupings such as push patterns (“the system pushes work to a worker”) and pull patterns (“the worker pulls work from the system”) to describe the many ways in which work can be distributed. By delineating these patterns in a form that is independent of specific workflow technologies and modelling languages, we are able to provide a comprehensive treatment of the resource perspective and we subsequently use these patterns as the basis for a detailed comparison of a number of commercially available workflow management systems.

Formal semantics and analysis of control flow in WS-BPEL

Web service composition refers to the creation of new (Web) services by combination of functionality provided by existing ones. This paradigm has gained significant attention in the Web services community and is seen as a pillar for building service-oriented applications. A number of domain-specific languages for service composition have been proposed with consensus being formed around a process-oriented language known as WS-BPEL (or BPEL). The kernel of BPEL consists of simple communication primitives that may be combined using control-flow constructs expressing sequence, branching, parallelism, synchronisation, etc. As a result, BPEL process definitions lend themselves to static flow-based analysis techniques. In this report, we describe a tool that performs two useful types of static checks and extracts meta-data to optimise dynamic resource management. The tool operates by translating BPEL processes into Petri nets and exploiting existing Petri net analysis techniques. It relies on a comprehensive and rigorously defined mapping of BPEL constructs into Petri net structures.

Service interaction patterns

With increased sophistication and standardization of modeling languages and execution platforms supporting business process management (BPM) across traditional boundaries, has come the need for consolidated insights into their exploitation from a business perspective. Key technology developments in BPM bear this out, with several web services-related initiatives investing significant effort in the collection of compelling use cases to heighten the exploitation of BPM in multi-party collaborative environments. In this setting, we present a collection of patterns of service interactions which allow emerging web services functionality, especially that pertaining to choreography and orchestration, to be benchmarked against abstracted forms of representative scenarios. Beyond bilateral interactions, these patterns cover multilateral, competing, atomic and causally related interactions. Issues related to the implementation of these patterns using established and emerging web services standards, most notably BPEL, are discussed.

Advanced Workflow Patterns

Conventional workflow functionality like task sequencing, split parallelism, join synchronization and iteration have proven effective for business process automation and have widespread support in current workflow products. However, newer requirements for workflows are encountered in practice, opening grave uncertainties about the extensions for current languages. Different concepts, although outwardly appearing to be more or less the same, are based on different paradigms, have fundamentally different semantics and different levels of applicability – more specialized for modeling or more generalized for workflow engine posit. By way of developmental insight of new requirements, we define workflow patterns which are described imperatively but independently of current workflow languages. These patterns provide the basis for an in-depth comparison of 12 workflow management systems. As such, the work reported in this paper can be seen as the academic response to evaluations made by prestigious consulting companies. Typically, these evaluations hardly consider the workflow modeling language and routing capabilities and focus more on the purely technical and commercial aspects.

UML Activity Diagrams as a Workflow Specification Language

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 and the adequacy of activity diagrams for workflow specification, by systematically evaluating their ability to capture a collection of workflow patterns. This analysis provides insights into the relative strengths and weaknesses of activity diagrams. In particular, it is shown that, given an appropriate clarification of their semantics, activity diagrams are able to capture situations arising in practice, which cannot be captured by most commercial Workflow Management Systems. On the other hand, the study shows that activity diagrams fail to capture some useful situations, thereby suggesting directions for improvement.

Verification of workflow task structures: A petri-net-based approach

Abstract While many workflow management systems have emerged in recent years, few of them provide any form of support for verification. Consequently, most workflows become operational before they have been thoroughly checked. This frequently results in runtime errors which need to be corrected on-the-fly at, typically, prohibitive costs. This paper shows how verification of a typical process control specification, which is at the heart of most workflow specifications, can benefit from state-of-the-art Petri-net based analysis techniques. To illustrate the applicability of the approach, a verification tool has been developed. This tool can download and verify the correctness of process definitions designed with Staffware, one of the leading workflow management systems.

Worklets: a service-oriented implementation of dynamic flexibility in workflows

This paper presents the realisation, using a Service Oriented Architecture, of an approach for dynamic flexibility and evolution in workflows through the support of flexible work practices, based not on proprietary frameworks, but on accepted ideas of how people actually work A set of principles have been derived from a sound theoretical base and applied to the development of worklets, an extensible repertoire of self-contained sub-processes aligned to each task, from which a dynamic runtime selection is made depending on the context of the particular work instance.

What's in a Service?

A proper understanding of the general nature, potential and obligations of electronic services may be achieved by examining existing commercial services in detail. The everyday services that surround us, and the ways in which we engage with them, are the result of social and economic interaction that has taken place over a long period of time. If we attempt to provide electronic services, and do not take this history into account, then we will fail. Any attempt to provide automated electronic services that ignores this history will deny consumers the opportunity to negotiate and refine, over a large range of issues, the specific details of the actual service to be provided. To succeed, we require a rich and accurate means of representing services. An essential ingredient of service representation is capturing the non-functional properties of services. These include the methods of charging and payment, the channels by which the service is requested and provided, constraints on temporal and spatial availability, service quality, security, trust and the rights attached to a service. Not only are comprehensive descriptions essential for useful service discovery, they are also integral to service management, enabling service negotiation, composition, and substitution. This paper builds on an understanding of services and their interactions, to outline the non-functional properties of services and their uses.