| Abstract [eng] |
The concept of service-oriented architecture (SOA) becomes increasingly popular in the field of information systems as well as software systems engineering. The symbiosis between an Enterprise Architecture and SOA results in so-called Service-Oriented Enterprise Architecture. Systems that implement this architecture are addressed as service-oriented enterprise systems (SoES). They are composed of enterprise business services (EBS), i.e. components implementing some business logic that is embedded in web services. EBS is not a software product because it is a service. This raises a number of new software engineering problems including problem of assessment of investments necessary for the development and implementation of new EBSs. In order to assess required investments, the quality of each EBS (QoSEBS) should be planned at least roughly. It is far not simple problem because a number of stakeholders, which interpret the concept of QoSEBS differently and plan it from different role-dependent perspectives, are involved in this process. In addition, a right conceptual basis for describing QoSEBS planning algorithms and even QoSEBS itself still is absent. Conflicts between the requirements arise not only due to the role-dependent perspectives (service owner, computer network administrator, infrastructure administrator, service user, etc.), from which different stakeholders see this new service, but also due to a different understanding of the quality concept itself or, in other words, due to different viewpoints to the quality. Usually it is done during a long-lasting and time-consuming negotiation process. So, it is very desirable to replace this process by an appropriate software system. However, the existing theoretical basis is not mature enough for the development of such software and, consequently, some theoretical research should be performed for its improvement. The symbiosis between Enterprise Architecture (EA) and Service-Oriented Architecture (SOA) results in the so-called Service-Oriented Enterprise Architecture (SoEA) and brings up new problems for Service-Oriented Enterprise Systems (SoES) engineering. In the context of SoES, a number of different stakeholders exist. They have different, often conflicting understandings of a SoES business service quality and different opinions on how such a service should be defined, specified, and evaluated. Thus, despite a large number of existing QoS models and ontologies, the question “What does QoS mean?” still has no final answer, at least, in the context of SoES. This concept is still not well-defined even for the traditional SOA service. The concept of “Quality of Service” is still remains murky. Its definition strongly depends on the topic of discourse and is usually not adaptable to other discourses. The first thing that should be done to examine QoSEBS is to investigate the nature of the quality of enterprise business service (QoSEBS) and to define this concept more precisely. In turn, to do that, it is necessary to make analysis of different understandings of QoS and QoSEBS, to systematize and to generalize these understandings and to relate them each to other. It means that a theory of meaning should be developed for the QoSEBS. The theory of QoSEBS meaning is a conceptual basis for an empiric QoSEBS planning, prediction, and evaluation theory that should provide models, methods, and algorithms to solve the related planning, prediction and evaluation problems. The dissertation seeks to contribute to this field by developing a fragment of such an empiric theory aimed at the preliminary planning of QoSEBS for particular EBS and a fragment of the QoSEBS meaning theory, required to describe the related models, methods, and algorithms. The research is rather exploratory research and does not pretend to an exhaustive investigation of all the mentioned issues in detail. In an informal way, the problem investigated in the dissertation is formulated as follows: “Giving role-depended, subjective and conflicting preliminary requirements, that define an acceptable quality level of bottom level quality sub characteristics to be implemented in a particular web-based SoES, an enterprise business service, specified by a number of different stakeholders, to resolve conflicts and define preliminary requirements for the acceptable quality level of EBS quality characteristics.”. |
