1,279 research outputs found
Knowledge Representation Concepts for Automated SLA Management
Outsourcing of complex IT infrastructure to IT service providers has
increased substantially during the past years. IT service providers must be
able to fulfil their service-quality commitments based upon predefined Service
Level Agreements (SLAs) with the service customer. They need to manage, execute
and maintain thousands of SLAs for different customers and different types of
services, which needs new levels of flexibility and automation not available
with the current technology. The complexity of contractual logic in SLAs
requires new forms of knowledge representation to automatically draw inferences
and execute contractual agreements. A logic-based approach provides several
advantages including automated rule chaining allowing for compact knowledge
representation as well as flexibility to adapt to rapidly changing business
requirements. We suggest adequate logical formalisms for representation and
enforcement of SLA rules and describe a proof-of-concept implementation. The
article describes selected formalisms of the ContractLog KR and their adequacy
for automated SLA management and presents results of experiments to demonstrate
flexibility and scalability of the approach.Comment: Paschke, A. and Bichler, M.: Knowledge Representation Concepts for
Automated SLA Management, Int. Journal of Decision Support Systems (DSS),
submitted 19th March 200
CREOLE: a Universal Language for Creating, Requesting, Updating and Deleting Resources
In the context of Service-Oriented Computing, applications can be developed
following the REST (Representation State Transfer) architectural style. This
style corresponds to a resource-oriented model, where resources are manipulated
via CRUD (Create, Request, Update, Delete) interfaces. The diversity of CRUD
languages due to the absence of a standard leads to composition problems
related to adaptation, integration and coordination of services. To overcome
these problems, we propose a pivot architecture built around a universal
language to manipulate resources, called CREOLE, a CRUD Language for Resource
Edition. In this architecture, scripts written in existing CRUD languages, like
SQL, are compiled into Creole and then executed over different CRUD interfaces.
After stating the requirements for a universal language for manipulating
resources, we formally describe the language and informally motivate its
definition with respect to the requirements. We then concretely show how the
architecture solves adaptation, integration and coordination problems in the
case of photo management in Flickr and Picasa, two well-known service-oriented
applications. Finally, we propose a roadmap for future work.Comment: In Proceedings FOCLASA 2010, arXiv:1007.499
A formal verification framework and associated tools for enterprise modeling : application to UEML
The aim of this paper is to propose and apply a verification and validation approach to Enterprise Modeling that enables the user to improve the relevance and correctness, the suitability and coherence of a model by using properties specification and formal proof of properties
Towards Formal Interaction-Based Models of Grid Computing Infrastructures
Grid computing (GC) systems are large-scale virtual machines, built upon a
massive pool of resources (processing time, storage, software) that often span
multiple distributed domains. Concurrent users interact with the grid by adding
new tasks; the grid is expected to assign resources to tasks in a fair,
trustworthy way. These distinctive features of GC systems make their
specification and verification a challenging issue. Although prior works have
proposed formal approaches to the specification of GC systems, a precise
account of the interaction model which underlies resource sharing has not been
yet proposed. In this paper, we describe ongoing work aimed at filling in this
gap. Our approach relies on (higher-order) process calculi: these core
languages for concurrency offer a compositional framework in which GC systems
can be precisely described and potentially reasoned about.Comment: In Proceedings DCM 2013, arXiv:1403.768
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
Semantic Business Process Modeling
This book presents a process-oriented business modeling framework based on semantic technologies. The framework consists of modeling languages, methods, and tools that allow for semantic modeling of business motivation, business policies and rules, and business processes. Quality of the proposed modeling framework is evaluated based on the modeling content of SAP Solution Composer and several real-world business scenarios
A System for Deduction-based Formal Verification of Workflow-oriented Software Models
The work concerns formal verification of workflow-oriented software models
using deductive approach. The formal correctness of a model's behaviour is
considered. Manually building logical specifications, which are considered as a
set of temporal logic formulas, seems to be the significant obstacle for an
inexperienced user when applying the deductive approach. A system, and its
architecture, for the deduction-based verification of workflow-oriented models
is proposed. The process of inference is based on the semantic tableaux method
which has some advantages when compared to traditional deduction strategies.
The algorithm for an automatic generation of logical specifications is
proposed. The generation procedure is based on the predefined workflow patterns
for BPMN, which is a standard and dominant notation for the modeling of
business processes. The main idea for the approach is to consider patterns,
defined in terms of temporal logic,as a kind of (logical) primitives which
enable the transformation of models to temporal logic formulas constituting a
logical specification. Automation of the generation process is crucial for
bridging the gap between intuitiveness of the deductive reasoning and the
difficulty of its practical application in the case when logical specifications
are built manually. This approach has gone some way towards supporting,
hopefully enhancing our understanding of, the deduction-based formal
verification of workflow-oriented models.Comment: International Journal of Applied Mathematics and Computer Scienc
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