A structured approach to VO reconfigurations through Policies

One of the strength of Virtual Organisations is their ability to dynamically and rapidly adapt in response to changing environmental conditions. Dynamic adaptability has been studied in other system areas as well and system management through policies has crystallized itself as a very prominent solution in system and network administration. However, these areas are often concerned with very low-level technical aspects. Previous work on the APPEL policy language has been aimed at dynamically adapting system behaviour to satisfy end-user demands and - as part of STPOWLA - APPEL was used to adapt workflow instances at runtime. In this paper we explore how the ideas of APPEL and STPOWLA can be extended from workflows to the wider scope of Virtual Organisations. We will use a Travel Booking VO as example.Comment: In Proceedings FAVO 2011, arXiv:1204.579

The SENSORIA reference modelling language

This chapter provides an overview of SRML - the Sensoria Reference Modelling Language. Our focus will be on the language primitives that SRML offers for modelling business services and activities, the methodological approach that SRML supports, and the mathematical semantics the underpins the modelling approach, including techniques for qualitative and quantitative analysis. © 2011 Springer-Verlag Berlin Heidelberg

From StPowla processes to SRML models

Service Oriented Computing is a paradigm for developing software systems as the composition of a number of services. Services are loosely coupled entities, that can be dynamically published, discovered and invoked over a network. The engineering of such systems presents novel challenges, mostly due to the dynamicity and distributed nature of service-based applications. In this paper, we focus on the modelling of service orchestrations. We discuss the relationship between two languages developed under the Sensoria project: SRML as a high level modelling language for Service Oriented Architectures, and StPowla as a process-oriented orchestration approach that separates core business processes from system variability at the end-user’s level, where the focus is towards achieving business goals. A fundamental challenge of software engineering is to correctly align business goals with IT strategy, and as such we present an encoding of StPowla to SRML. This provides a formal framework for StPowla and also a separated view of policies representing system variability that is not present in SRML

Engineering Service Oriented Applications: From StPowla Processes to SRML Models

Service Oriented Computing is a paradigm for developing software systems as the composition of a number of services. Services are loosely coupled entities, can be dynamically published, discovered and invoked over a network. The engineering of such systems presents novel challenges, mostly due to the dynamicity and distributed nature of service-based applications. In this paper, we focus on the modelling of service orchestrations. We discuss the relationship between two languages developed under the Sensoria project: SRML as a high level modelling language for Service Oriented Architectures, and StPowla as a process-oriented orchestration approach that separates core business processes from system variability at the end-user’s level, where the focus is towards achieving business goals. We also extend the current status of StPowla to include workflow reconfigurations. A fundamental challenge of software engineering is to correctly align business goals with IT strategy, and as such we present an encoding of StPowla to SRML. This provides a formal framework for StPowla and also a separated view of policies representing system variability that is not present in SRML

Policy-driven Reconfiguration of Service-targeted Business Processes

Workflows are a key part of Business Process Management, o ering the potential to automate a number of business activities. Workflows are though constrained to their design, i.e. workflow functionality does not extend outside its own specification. A relatively small number of solutions to this inflexibility have been proposed. However, all approaches so far are either at the orchestration level or are tightly-coupled with the workflow, whereas we consider that the problem is at the business level and needs to be loosely coupled from the workflow. Significant value can be gained from separating core functionality in a workflow from variability to that core process. Both can be defined separately and yet still corporately execute to provide a variety of execution states that match the given context. Functionality of the workflow can be supplied by Service Oriented Architecture. Thus we define StPowla as a combination of workflows, policies and Service Oriented Architecture. Workflows define the core business process, policies define the possible variability of the processes and Service Oriented Architecture provides the underlying functionality. We specifically present a set of reconfiguration functions that can be called by policies on workflows and define each of these as graph transformation rules. We provide an encoding from StPowla processes to SRML models, including core workflow descriptions and variability, in order to make precise the relationship between the constituent parts of StPowla. We apply the StPowla approach to an industrial case study, provided by an industrial partner

Policy-driven reconfiguration of service-targeted business processes

Workflows are a key part of Business Process Management, o ering the potential to automate a number of business activities. Workflows are though constrained to their design, i.e. workflow functionality does not extend outside its own specification. A relatively small number of solutions to this inflexibility have been proposed. However, all approaches so far are either at the orchestration level or are tightly-coupled with the workflow, whereas we consider that the problem is at the business level and needs to be loosely coupled from the workflow. Significant value can be gained from separating core functionality in a workflow from variability to that core process. Both can be defined separately and yet still corporately execute to provide a variety of execution states that match the given context. Functionality of the workflow can be supplied by Service Oriented Architecture. Thus we define StPowla as a combination of workflows, policies and Service Oriented Architecture. Workflows define the core business process, policies define the possible variability of the processes and Service Oriented Architecture provides the underlying functionality. We specifically present a set of reconfiguration functions that can be called by policies on workflows and define each of these as graph transformation rules. We provide an encoding from StPowla processes to SRML models, including core workflow descriptions and variability, in order to make precise the relationship between the constituent parts of StPowla. We apply the StPowla approach to an industrial case study, provided by an industrial partner.EThOS - Electronic Theses Online ServiceGBUnited Kingdo