Models for Trustworthy Service and Process Oriented Systems

Service and process-oriented systems promise to provide more effective business and work processes and more flexible and adaptable enterprise IT systems. However, the technologies and standards are still young and unstable, making research in their theoretical foundations increasingly important. Our studies focus on two dichotomies: the global/local views of service interactions, and their imperative/declarative specification. A global view of service interactions describes a process as a protocol for interactions, as e.g. an UML sequence diagram or a WS-CDL choreography. A local view describes the system as a set of processes, e.g. specified as a mipi-calculus or WS-BPEL process, implementing each participant in the process. While the global view is what is usually provided as specification, the local view is a necessary step towards a distributed implementation. If processes are defined imperatively, the control flow is defined explicitly, e.g. as a sequence or flow graph of interactions/commands. In a declarative approach processes are described as a collection of conditions they should fulfill in order to be considered correct. The two approaches have evolved rather independently from each other. Our thesis is that we can provide a theoretical framework based on typed concurrent process and concurrent constraint calculi for the specification, analysis and verification of service and process oriented system designs which bridges the global and local view and combines the imperative and declarative specification approaches, and can be employed to increase the trust in the developed systems. This article describes our main motivations, results and future research directions

Extension du formalisme des flux opérationnels par une algèbre temporelle

National audienceWorkflows constitute an important language to represent knowledge about processes, but also increasingly to reason on such knowledge. On the other hand, there is a limit to which time constraints between activities can be expressed. Qualitative interval algebras can model processes using finer temporal relations, but they cannot reproduce all workflow patterns. This paper defines a common ground model-theoretical semantics for both workflows and interval algebras, making it possible for reasoning systems working with either to interoperate. Thanks to this, interesting properties and inferences can be defined, both on workflows and on an extended formalism combining workflows with interval algebras. Finally, similar formalisms proposing a sound formal basis for workflows and extending them are discussed.Les flux opérationnels (workflows) constituent un important langage de représentation des connaissances sur les processus, mais sont également de plus en plus utilisés pour raisonner sur ce type de connaissances. En revanche, ils sont limités pour l'expression de contraintes temporelles entre activités. Les algèbres qualitatives d'intervalles peuvent représenter des relations temporelles plus fines, mais elles sont incapables de reproduire toutes les structures de contrôle des flux. Cet article définit une sémantique, fondée sur la théorie des modèles, commune aux flux opérationnels et aux algèbres d'intervalles, rendant possible l'inter-opérabilité de systèmes de raisonnement utilisant ces deux formalismes. Cela met également en évidence des propriétés et des possibilités d'inférences intéressantes, à la fois pour les flux opérationnels et pour les flux étendus par l'utilisation d'une algèbre qualitative. Finalement, nous discutons de formalismes similaires, proposant également une base théorique au formalisme des flux et étendant ce dernier

Adaptive Process Management in Cyber-Physical Domains

The increasing application of process-oriented approaches in new challenging cyber-physical domains beyond business computing (e.g., personalized healthcare, emergency management, factories of the future, home automation, etc.) has led to reconsider the level of flexibility and support required to manage complex processes in such domains. A cyber-physical domain is characterized by the presence of a cyber-physical system coordinating heterogeneous ICT components (PCs, smartphones, sensors, actuators) and involving real world entities (humans, machines, agents, robots, etc.) that perform complex tasks in the “physical” real world to achieve a common goal. The physical world, however, is not entirely predictable, and processes enacted in cyber-physical domains must be robust to unexpected conditions and adaptable to unanticipated exceptions. This demands a more flexible approach in process design and enactment, recognizing that in real-world environments it is not adequate to assume that all possible recovery activities can be predefined for dealing with the exceptions that can ensue. In this chapter, we tackle the above issue and we propose a general approach, a concrete framework and a process management system implementation, called SmartPM, for automatically adapting processes enacted in cyber-physical domains in case of unanticipated exceptions and exogenous events. The adaptation mechanism provided by SmartPM is based on declarative task specifications, execution monitoring for detecting failures and context changes at run-time, and automated planning techniques to self-repair the running process, without requiring to predefine any specific adaptation policy or exception handler at design-time

An expanded and refined catalog of time patterns for workflows

Trabajos anteriores que definieron catálogos de patrones de control, recursos y datos para workflows tuvieron un rol fundamental en la evolución de esas dimensionesdentro de lenguajes y aplicaciones. Esos patrones han sido usados para evaluar la expresividad de los lenguajes, guiar su evolución, y para establecer una terminología básica que hoy en día es compartida por la mayoría de los desarrolladores de sistemas y lenguajes para workflows. Sin embargo, aún no se han obtenido resultados comparables en la dimensión de tiempo, a pesar de la gran importancia que esta tiene en muchos workflows y procesos de negocio. Aunque recientemente fueron propuestos algunos catálogos de patrones de tiempo, estas propuestas tienen variaslimitaciones en su alcance y en la precisión de las descripciones que los hacen inadecuados para tareas como evaluar lenguajes con respecto a su capacidad parasoportar esos patrones. En este artículo se presenta una aproximación para enfrentar este problema: por una parte, se presenta un catálogo extendido y refinado de patrones de tiempo para workflows; por otra parte, se presenta una formalización de dichos patrones basada en cálculo de eventos y en diagramas de estados, la cual permite hacer una evaluación de la expresividad de los lenguajes con respecto a los patrones y a la dimensión de tiempo

Investigating the Effort of Using Business Process Management Technology: Results from a Controlled Experiment

Business Process Management (BPM) technology has become an important instrument for supporting complex coordination scenarios and for improving business process performance. When considering its use, however, enterprises typically have to rely on vendor promises or qualitative reports. What is still missing and what is demanded by IT decision makers are quantitative evaluations based on empirical and experimental research. This paper picks up this demand and illustrates how experimental research can be applied to technologies enabling enterprises to coordinate their business processes and to associate them with related artifacts and resources. The conducted experiment compares the effort for implementing and maintaining a sample business process either based on standard workflow technology or on a case handling system. We motivate and describe the experimental design, discuss threats for the validity of our experimental results (as well as risk mitigations), and present the results of our experiment. In general, more experimental research is needed in order to obtain valid data on the various aspects and effects of BPM technology and BPM tools

Change Support in Process-Aware Information Systems - A Pattern-Based Analysis

In today's dynamic business world the economic success of an enterprise increasingly depends on its ability to react to changes in its environment in a quick and flexible way. Process-aware information systems (PAIS) offer promising perspectives in this respect and are increasingly employed for operationally supporting business processes. To provide effective business process support, flexible PAIS are needed which do not freeze existing business processes, but allow for loosely specified processes, which can be detailed during run-time. In addition, PAIS should enable authorized users to flexibly deviate from the predefined processes if required (e.g., by allowing them to dynamically add, delete, or move process activities) and to evolve business processes over time. At the same time PAIS must ensure consistency and robustness. The emergence of different process support paradigms and the lack of methods for comparing existing change approaches have made it difficult for PAIS engineers to choose the adequate technology. In this paper we suggest a set of changes patterns and change support features to foster the systematic comparison of existing process management technology with respect to process change support. Based on these change patterns and features, we provide a detailed analysis and evaluation of selected systems from both academia and industry. The identified change patterns and change support features facilitate the comparison of change support frameworks, and consequently will support PAIS engineers in selecting the right technology for realizing flexible PAIS. In addition, this work can be used as a reference for implementing more flexible PAIS

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? i.e. in other words what is the state-of-the-art in the area?. To gain an insight into the area, 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 modeling 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, documented in earlier works. 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 which describes the various ways in which work is distributed amongst business users and managed through to completion