Yet Another Workflow Language Research Articles

Data Warehousing Process Modeling from Classical Approaches to New Trends: Main Features and Comparisons

The extract, transform, and load (ETL) process is at the core of data warehousing architectures. As such, the success of data warehouse (DW) projects is essentially based on the proper modeling of the ETL process. As there is no standard model for the representation and design of this process, several researchers have made efforts to propose modeling methods based on different formalisms, such as unified modeling language (UML), ontology, model-driven architecture (MDA), model-driven development (MDD), and graphical flow, which includes business process model notation (BPMN), colored Petri nets (CPN), Yet Another Workflow Language (YAWL), CommonCube, entity modeling diagram (EMD), and so on. With the emergence of Big Data, despite the multitude of relevant approaches proposed for modeling the ETL process in classical environments, part of the community has been motivated to provide new data warehousing methods that support Big Data specifications. In this paper, we present a summary of relevant works related to the modeling of data warehousing approaches, from classical ETL processes to ELT design approaches. A systematic literature review is conducted and a detailed set of comparison criteria are defined in order to allow the reader to better understand the evolution of these processes. Our study paints a complete picture of ETL modeling approaches, from their advent to the era of Big Data, while comparing their main characteristics. This study allows for the identification of the main challenges and issues related to the design of Big Data warehousing systems, mainly involving the lack of a generic design model for data collection, storage, processing, querying, and analysis.

Designing Conceptual Framework for Aligning Service Oriented Architecture with Business Process

A problem in most of the organizations is to find the best way to mature their business processes. Process maturity can make the organizations more profitable and competent for other competitors. The problem can be solved by aligning service oriented architecture (using web services) with business processes within the organization. The purpose of this paper is to design a conceptual framework for aligning business processes with the Service Oriented Architecture and then prove the framework’s validity using simulation. An organization is working in education sector and wants to integrate its multiple web applications to allow data flow from one system to another. The framework will help the organization to align business process of service oriented architecture and to easily mold their business process according to business needs. The framework’s validity will be proved by simulating the entire process using Yet Another Workflow Language (YAWL).

Formal Specification of the Assurance Point Web Service Composition Model

This paper presents a formal specification of the Assurance Point (AP) web service composition model. The AP model provides a flexible way of checking constraints and responding to execution errors in service composition. An AP is a combined logical and physical checkpoint, providing an execution milestone that stores critical data and interacts with integration rules (IRs) to alter program flow and to invoke different forms of recovery depending on the execution status. In this paper, the execution and recovery semantics of assurance points have been fully defined in the context of if-else, parallel, and loop control structures. The activities and complex control structures of the AP model have been formalized and tested in the Yet Another Workflow Language (YAWL) engine. By doing so, the correctness of the execution and recovery semantics in the AP model has been verified, demonstrating that YAWL nets of the AP model satisfy the soundness property. Different from existing web service composition models, the AP model presented by this research provides multiple levels of protection against service execution failure with a combination of forward and backward recovery techniques.

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 guage's 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.

Transformation of BPMN Diagrams to YAWL Nets

Business Process Modeling Notation (BPMN) is the de facto standard for modeling business processes on a conceptual level. However, BPMN lacks a formal semantics and many of its features need to be further interpret, Consequently that hinders BPMN as a standard to statically check the semantic correctness of models. YAWL (Yet Another Workflow Language) allows the specification of executable workflow models. A transformation between these two languages enables the integration of different levels of abstraction in process modeling. This paper discusses how to transform BPMN diagrams to YAWL nets. The benefits of the transformation are threefold. Firstly, it clarifies the semantics of BPMN via a mapping to YAWL. Secondly, the deployment of BPMN business process models is simplified. Thirdly, BPMN models can be analyzed with YAWL verification tools.

Surmounting BPM challenges: the YAWL story

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

Business process verification – finally a reality!

PurposeThe purpose of this paper is to demonstrate that process verification has matured to a level where it can be used in practice. This paper reports on new verification techniques that can be used to assess the correctness of real‐life models.Design/methodology/approachThe proposed approach relies on using formal methods to determine the correctness of business processes with cancellation and OR‐joins. The paper also demonstrates how reduction rules can be used to improve the efficiency. These techniques are presented in the context of the workflow language yet another workflow language (YAWL) that provides direct support for 20 most frequently used patterns found today (including cancellation and OR‐joins). But the results also apply to other languages with these features (e.g. BPMN, EPCs, UML activity diagrams, etc.). An editor has been developed that provides diagnostic information based on the techniques presented in this paper.FindingsThe paper proposes four properties for business processes with cancellation and OR‐joins, namely: soundness, weak soundness, irreducible cancellation regions and immutable OR‐joins and develop new techniques to verify these properties. Reduction rules have been used as a means of improving the efficiency of the algorithm. The paper demonstrates the feasibility of this verification approach using a realistic and complex business process, the visa application process for general skilled migration to Australia, modelled as a YAWL workflow with cancellation regions and OR‐joins.Originality/valueBusiness processes sometimes require complex execution interdependencies to properly complete a process. For instance, it is possible that certain activities need to be cancelled mid‐way though the process. Some parallel activities may require complex “wait and see” style synchronisation depending on a given context. These types of business processes can be found in various domains, such as application integration, B2B commerce, web service composition and workflow systems. Even though cancellation and sophisticated join structures are present in many business processes, existing verification techniques are unable to deal with such processes. Hence, this paper plays an important role in making process verification a reality.

Workflow-based semantics for peer-to-peer specifications

In this paper we introduce SMoL, a simplified BPEL-like language for specifying peer and service behaviour in P2P systems. We then define a transformational semantics of SMoL in terms of Yet Another Workflow Language (YAWL) workflows, which enables the simulation (e.g., testing possible execution scenarios) and analysis (e.g., verifying reachability or lock freedom) of the behaviour of P2P peers and services.

Verifying Workflows with Cancellation Regions and OR-joins: An Approach Based on Relaxed Soundness and Invariants

YAWL (Yet Another Workflow Language) workflow language supports the most frequent control-flow patterns found in the current workflow practice. As a result, most workflow languages can be mapped onto YAWL without the loss of control-flow details, even languages allowing for advanced constructs such as cancellation regions and OR-joins. Hence, a verification approach for YAWL is desirable, because such an approach could be used for any workflow language that can be mapped onto YAWL. Unfortunately, cancellation regions and OR-joins are ‘non-local’ properties, and in general we cannot even decide whether the desired final state is reachable if both patterns are present. This paper proposes a verification approach based on (i) an abstraction of the OR-join semantics; (ii) the relaxed soundness property; and (iii) transition invariants. This approach is correct (errors reported are really errors), but not necessarily complete (not every error might get reported). This incompleteness can be explained because, on the one hand, the approach abstracts from the OR-join semantics and on the other hand, it may use only transition invariants, which are structural properties. Nevertheless, our approach can be used to successfully detect errors in YAWL models. Moreover, the approach can be easily transferred to other workflow languages allowing for advanced constructs such as cancellations and OR-joins.

YAWL: yet another workflow language

Based on a rigorous analysis of existing workflow management systems and workflow languages, a new workflow language is proposed: yet another workflow language (YAWL). To identify the differences between the various languages, we have collected a fairly complete set of workflow patterns. Based on these patterns we have evaluated several workflow products and detected considerable differences in their ability to capture control flows for non-trivial workflow processes. Languages based on Petri nets perform better when it comes to state-based workflow patterns. However, some patterns (e.g. involving multiple instances, complex synchronisations or non-local withdrawals) are not easy to map onto (high-level) Petri nets. This inspired us to develop a new language by taking Petri nets as a starting point and adding mechanisms to allow for a more direct and intuitive support of the workflow patterns identified. This paper motivates the need for such a language, specifies the semantics of the language, and shows that soundness can be verified in a compositional way. Although YAWL is intended as a complete workflow language, the focus of this paper is limited to the control-flow perspective.