919 research outputs found
SECURITY POLICY ENFORCEMENT IN APPLICATION ENVIRONMENTS USING DISTRIBUTED SCRIPT-BASED CONTROL STRUCTURES
Business processes involving several partners in different organisations impose demanding
requirements on procedures for specification, execution and maintenance. A
framework referred to as business process management (BPM) has evolved for this purpose
over the last ten years. Other approaches, such as service-oriented architecture
(SOA) or the concept of virtual organisations (VOs), assist in the definition of architectures
and procedures for modelling and execution of so-called collaborative business
processes (CBPs).
Methods for the specification of business processes play a central role in this context,
and, several standards have emerged for this purpose. Among these, Web Services
Business Process Execution Language (WS-BPEL, usually abbreviated BPEL) has
evolved to become the de facto standard for business process definition. As such, this
language has been selected as the foundation for the research in this thesis.
Having a broadly accepted standard would principally allow the specification of
business processes in a platform-independent manner, including the capability to
specify them at one location and have them executed at others (possibly spread across
different organisations). Though technically feasible, this approach has significant
security implications, particularly on the side that is to execute a process.
The research project focused upon these security issues arising when business processes
are specified and executed in a distributed manner. The central goal has been the
development of methods to cope with the security issues arising when BPEL as a
standard is deployed in such a way exploiting the significant aspect of a standard to be
platform-independent
The research devised novel methods for specifying security policies in such a manner
that the assessment of compliance with these policies is greatly facilitated such that the
assessment becomes suited to be performed automatically. An analysis of the securityrelevant
semantics of BPEL as a specification language was conducted that resulted in
the identification of so-called security-relevant semantic patterns. Based on these
results, methods to specify security policy-implied restrictions in terms of such semantic
patterns and to assess the compliance of BPEL scripts with these policies have been
developed. These methods are particularly suited for assessment of remotely defined
BPEL scripts since they allow for pre-execution enforcement of local security policies
thereby mitigating or even removing the security implications involved in distributed
definition and execution of business processes.
As initially envisaged, these methods are comparatively easy to apply, as they are based
on technologies customary for practitioners in this field. The viability of the methods
proposed for automatic compliance assessment has been proven via a prototypic
implementation of the essential functionality required for proof-of-concept.Darmstadt Node of the NRG Network at University of Applied Sciences Darmstad
Web Services Support for Dynamic Business Process Outsourcing
Outsourcing of business processes is crucial for organizations to be effective, efficient and flexible. To meet fast-changing market conditions, dynamic outsourcing is required, in which business relationships are established and enacted on-the-fly in an adaptive, fine-grained way unrestricted by geographic distance. This requires automated means for both the establishment of outsourcing relationships and for the enactment of services performed in these relationships over electronic channels. Due to wide industry support and the underlying model of loose coupling of services, Web services increasingly become the mechanism of choice to connect organizations across organizational boundaries. This paper analyzes to which extent Web services support the dynamic process outsourcing paradigm. We discuss contract -based dynamic business process outsourcing to define requirements and then introduce the Web services framework. Based on this, we investigate the match between the two. We observe that the Web services framework requires further support for cross - organizational business processes and mechanisms for contracting, QoS management and process-based transaction support and suggest ways to fill those gaps
Context constraint integration and validation in dynamic web service compositions
System architectures that cross organisational boundaries are usually implemented based on Web service technologies due to their inherent interoperability benets. With increasing exibility requirements, such as on-demand service provision, a dynamic approach to service architecture focussing on composition at runtime is needed. The possibility of technical faults, but also violations of functional and semantic constraints require a comprehensive notion of context that captures composition-relevant aspects. Context-aware techniques are consequently required to support constraint validation for dynamic service composition. We present techniques to respond to problems occurring during the execution of dynamically composed Web
services implemented in WS-BPEL. A notion of context { covering physical and contractual
faults and violations { is used to safeguard composed service executions dynamically. Our aim is to present an architectural framework from an application-oriented perspective, addressing practical considerations of a technical framework
Integration of BPM systems
New technologies have emerged to support the global economy where for instance suppliers, manufactures and retailers are working together in order to minimise the cost and
maximise efficiency. One of the technologies that has become a buzz word for many businesses is business process management or BPM. A business process comprises activities
and tasks, the resources required to perform each task, and the business rules linking these activities and tasks. The tasks may be performed by human and/or machine actors.
Workflow provides a way of describing the order of execution and the dependent relationships between the constituting activities of short or long running processes.
Workflow allows businesses to capture not only the information but also the processes that transform the information - the process asset (Koulopoulos, T. M., 1995). Applications which involve automated, human-centric and collaborative processes across organisations are
inherently different from one organisation to another. Even within the same organisation but over time, applications are adapted as ongoing change to the business processes is seen as the norm in today’s dynamic business environment. The major difference lies in the specifics of business processes which are changing rapidly in order to match the way in which businesses operate. In this chapter we introduce and discuss Business Process Management (BPM) with a focus on the integration of heterogeneous BPM systems across multiple organisations. We identify the problems and the main challenges not only with regards to technologies but also in the social and cultural context. We also discuss the issues that have arisen in our bid to find the solutions
Modelling and Analysis Using GROOVE
In this paper we present case studies that describe how the graph transformation tool GROOVE has been used to model problems from a wide variety of domains. These case studies highlight the wide applicability of GROOVE in particular, and of graph transformation in general. They also give concrete templates for using GROOVE in practice. Furthermore, we use the case studies to analyse the main strong and weak points of GROOVE
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Towards an aspect weaving BPEL engine
This position paper proposes the use of dynamic aspects and
the visitor design pattern to obtain a highly configurable and
extensible BPEL engine. Using these two techniques, the
core of this infrastructural software can be customised to
meet new requirements and add features such as debugging,
execution monitoring, or changing to another Web Service
selection policy. Additionally, it can easily be extended to
cope with customer-specific BPEL extensions. We propose
the use of dynamic aspects not only on the engine itself
but also on the workflow in order to tackle the problems of
Web Service hot deployment and hot fixes to long running
processes. In this way, composing aWeb Service "on-the-fly"
means weaving its choreography interface into the workflow
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