Automated error correction of business process models

As order dependencies between process tasks can get complex, it is easy to make mistakes in process model design, especially behavioral ones such as deadlocks. Notions such as soundness formalize behavioral errors and tools exist that can identify such errors. However these tools do not provide assistance with the correction of the process models. Error correction can be very challenging as the intentions of the process modeler are not known and there may be many ways in which an error can be corrected. We present a novel technique for automatic error correction in process models based on simulated annealing. Via this technique a number of process model alternatives are identified that resolve one or more errors in the original model. The technique is implemented and validated on a sample of industrial process models. The tests show that at least one sound solution can be found for each input model within a reasonable response time

Workflow control-flow patterns : a revised view

The Workflow Patterns Initiative was established with the aim of delineating the fundamental requirements that arise during business process modelling on a recurring basis and describe them in an imperative way. The first deliverable of this research project was a set of twenty patterns describing the control-flow perspective of workflow systems. Since their release, these patterns have been widely used by practitioners, vendors and academics alike in the selection, design and development of workflow systems [vdAtHKB03]. This paper presents the first systematic review of the original twenty control-flow patterns and provides a formal description of each of them in the form of a Coloured Petri-Net (CPN) model. It also identifies twenty three new patterns relevant to the control-flow perspective. Detailed context conditions and evaluation criteria are presented for each pattern and their implementation is assessed in fourteen commercial offerings including workflow and case handling systems, business process modelling formalisms and business process execution languages

Dimensions of coupling in middleware

It is well accepted that different types of distributed architectures require different degrees of coupling. For example, in client-server and three-tier architectures, application components are generally tightly coupled, both with one-another and with the underlying middleware. Meanwhile, in off-line transaction processing, grid computing and mobile applications, the degree of coupling between application components and with the underlying middleware needs to be minimised. Terms such as "synchronous", "asynchronous", "blocking", "non-blocking", "directed", and "non-directed" are often used to refer to the degree of coupling required by an architecture or provided by a middleware. However, these terms are used with various connotations. And while various informal definitions have been provided, there is a lack of an overarching formal framework to unambiguously communicate architectural requirements with respect to (de-)coupling. This article addresses this gap by: (i) formally defining three dimensions of (de-)coupling; (ii) relating these dimensions to existing middleware; and (iii) proposing notational elements to represent various coupling integration patterns. This article also discusses a prototype that demonstrates the feasibility of its implementation

newYAWL : achieving comprehensive patterns support in workflow for the control-flow, data and resource perspectives

The Workflow Patterns provide a conceptual foundation for the control-flow, data and resource perspectives of process-aware information systems (PAIS). In this paper we present newYAWL, a reference language for PAIS based on the workflow patterns. newYAWL radically extends previous work undertaken on the YAWL language and provides a comprehensive formal description of how the complete set of workflow patterns can be realized and integrated in the context of an operational PAIS

Facilitating process analysis through visualising process history: experiences with a Dutch municipality

Nowadays vast quantities of data are stored as a result of the operation of software systems and devices. The analysis of this data can provide valuable insights. In the field of Business Process Management, event logs may provide valuable information for business process improvement. This is the realm of process mining, an area which has provided many analysis techniques over the past decade. Despite the abundance of process mining techniques, it remains a challenge to provide results that are understandable by domain experts. Discovered process models are often perceived as abstract and static. Conformance checking techniques provide detailed results that are only understandable for process analysts. Therefore, we propose an approach to dynamically visualize event data on intuitive 'maps'. States of the process are visualized on a collection of maps thus resulting in sequences of 'photographs' of the process under investigation. By replaying the event log using such visualizations we can create a collection of 'process movies'. Our visualisation approach has been implemented in ProM and allows for any type of 'map' as long as activity instances can be associated to map coordinates. Moreover, the approach has been evaluated in collaboration with a Dutch municipality

Turning event logs into process movies : animating what has really happened

Today's information systems log vast amount of data which contains information about the actual execution of business processes. The analysis of this data can provide a solid starting point for business process improvement. This is the realm of process mining, an area which has provided a repertoire of many analysis techniques. Despite the impressive capabilities of existing process mining algorithms, dealing with the abundance of data recorded by contemporary systems and devices remains a challenge. Of particular importance is the capability to guide the meaningful interpretation of this 'ocean' of data by process analysts. To this end, insights from the field of visual analytics can be leveraged. An approach is proposed where process states are reconstructed from event logs and visualised in succession, leading to an animated history of a process. This approach is customisable in how a process state, partially defined through a collection of activity instances, is visualised: one can select a map and specify a projection of activity instances on this map based on their properties. In this paper an implementation of the proposal is described for the open-source process-mining framework ProM along with reporting an evaluation with one of Australia's largest insurance companies: Suncorp

Reduction rules for YAWL workflow nets with cancellation regions and OR-joins

A reduction rule can transform a large net into a smaller and simple net while preserving certain interesting properties and it is usually applied before verification to reduce the complexity and to prevent state space explosion. Reset nets have been proposed to formally describe workflows with cancellation behaviour. In our previous work, we have presented a set of reduction rules for Reset Workflow Net (RWF-net), which is a subclass of reset nets. In this paper, we will present a set of reduction rules for YAWL nets with cancellation regions and OR-joins. The reduction rules for RWF-nets combined with the formal mappings from YAWL nets provide us with the means to dene a set of reduction rules for YAWL nets. We will also demonstrate how these reduction rules can be used for efficient verification of YAWL nets these features

Reduction rules for reset workflow nets

When a workflow contains a large number of tasks and involves complex control flow dependencies, verification can take too much time or it may even be impossible. Reduction rules can be used to abstract from certain transitions and places in a large net and thus could cut down the size of the net used for verification. Petri nets have been proposed to model and analyse workflows and Petri nets reduction rules have been used for efficient verification of various properties of workflows, such as liveness and boundedness. Reset nets are Petri nets with reset arcs, which can remove tokens from places when a transition fires. The nature of reset arcs closely relates to the cancellation behaviour in workflows. As a result, reset nets have been proposed to formally represent workflows with cancellation behaviour, which is not easily modelled in ordinary Petri nets. Even though reduction rules exist for Petri nets, the nature of reset arcs could invalidate the transformation rules applicable to Petri nets. This motivated us to consider possible reduction rules for reset nets. In this paper, we propose a number of reduction rules for Reset Workflow Nets (RWF-nets) that are soundness preserving. These reduction rules are based on reduction rules available for Petri nets [19] and we present the necessary conditions under which these rules hold in the context of reset nets

Pattern-based analysis 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 and data 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 and data 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 draft specificatio