Dienstgütebehandlung im Dienstlebenszyklus

Description and survey of the possible, guaranteed or offered
quality of a service (QoS) is one of the key features to establish
a performance and quality oriented assesment or accounting of
IT-services. This task is accomplished using various criteria - the
so called QoS-characteristics - which, in most cases, are specific
to a certain service. From the point of view of the service life
cycle, characteristics of a service are evaluated with in the usage
phase but are usually determined in the negotiation phase before a
service is implemented. The realization of this specifications in
the following phases of the service life cycle, service
provisioning or implementation and service usage, has not been
methodically supported until now and has to be done by hand . Thus,
the impact of a specification made in the negotiation phase on the
other life cycle phases can only be estimated with expert
knowledge. An objective assessment of this impact is impossible.
The work presented introduces a technique enabling the formal
specification of QoScharacteristics, thus allowing an automatic
realization of the specification in the provisioning and usage
phase of a service. Until now, only isolated approaches on the
specification of QoS-characteristics focusing on specific
technologies have been made. In this thesis we present a completely
technology independent approach distilled from the typical
processes used for measuring QoS in different technologies. In
order to implement this idea, a formal model of a common
measurement process, based on the MNM service model, is introduced
and the specification of a QoScharacteristic is formalized as a
refinement of this model. A formal language, capable of
facilitating the generation of these models has been developed for
this purpose. Consequently, a compiler for this language has been
developed to automatically generate a measurement system out of the
specification of a QoS-characteristic. This enables the uniform and
technology independent specification of QoS-characteristics. In
conclusion, a concept for the computer aided specification of
QoS-characteristics has been established which, as an audit
included in this thesis demonstrates, can be applied to various
scenarios in the area of service management. The concept introduced
adds quality orientation to existing approaches like CSM (customer
service management) and thus paves the way to quality oriented
service management.