MOQ: Web services ontologies for QoS and general quality evaluations

Abstract

When describing Web services, one of the obvious aspects that needs representing is Quality of Service" (QoS), the capability of a Web service to meet an acceptable level of service as per factors such as availability and accessibility. However too much of a focus on developing functional QoS ontologies has led to an over-emphasis on representing solely QoS metrics and units of measurement. For instance, what does round trip time actually mean? Is the round trip time of every data item measured? Is it an average, or is every nth item measured? Is it the actual time that is important or just the % of items that are beyond a certain range? Arguably existing QoS ontologies cannot readily answer many of these design questions because these questions have less to do with evaluating QoS and more to do with representing "what is quality?" Therefore, there is an unmet need for Web services ontologies that are designed at a higher level encompassing domain independent concepts, and generally applicable beyond QoS evaluations. The MOQ set of ontologies designed from the premise that quality is "conformance to requirements" aims to fill this need. Comprised of ontologies of requirement, measurement, traceability, and quality management systems, MOQ can be extended to encompass QoS metrics and measurement units or be designed to interoperate with existing QoS ontology. Either way MOQ use promises to ensure that ambiguity in QoS evaluations is minimized.

A Semantic Model for Enhancing Network Services Management and Auditing

“…In [9] a new Service Level Objective (SLO) concept, metrics' monitoring and statistical calculation semantics are presented. MOQ [10] is another proposal of a QoS semantics model for WS, but it is not exactly an ontology. It only specifies axioms and does not present a taxonomy structure or a dictionary of concepts.…”

A semantic end-to-end QoS model for dynamic service oriented environments

“…For the purposes of this work, it is worth mentioning the service oriented computing community (e.g., [8,6,2,14,3]), the end-to-end QoS community (e.g., [7]), as well as the pervasive computing and mobile computing communities (e.g., [9,15]). Even if different in purpose, these efforts intended at least to identify relevant quality factors affecting QoS and being associated to a specific resource (e.g., an application service, a network, a device).…”

“…[6] proposes a methodology enabling to express user QoS requirements and to link them to quality factors using the notion of tracability. More recently, some authors [14,3] have derived semantic languages of QoS ontologies that represent generic models for QoS.…”

“…On one hand, we have ontologies tailored to a specific aspect of QoS centered on the service level [8,6,2]. These ontologies do not consider other important resources involved in services' provision such as the network and hardware infrastructure.…”

Evaluating Quality of Web Services: A Risk-Driven Approach

“…Bleul and Weiss [7] support service packaging and include a Unit-Transformation-Ontology to define functional relations between metrics. Four ontologies presented in [8]: requirements, measurement, traceability and quality management, aim to minimize ambiguities in QoS evaluations. An approach to specify user requirements with help of a QoS ontology and a requirement matching tool are presented in [9].…”