Eine Methode zur Spezifikation der IT-Service-Managementprozesse Verketteter Dienste

The growing complexity of IT services poses new challenges to IT Service Management (ITSM). The issue of end-to-end service quality challenges service providers, as most services are no longer realized stand-alone by a single provider but composed of multiple building blocks supplied by several providers. In the past, relationships between service providers were organised according to a hierarchical model: a service provider offers services to his customers and relies on a set of underpinning services delivered by sub-providers to realize these services. In their current releases, both the IT Infrastructure Library (ITIL) and the Enhanced Telecom Operations Map (eTOM) stress that due to new sourcing strategies, market trends like e-business or regulatory policies new necessities and also opportunities for collaboration between service providers arise. Beyond the hierarchical model, alternative forms of provider cooperation gain importance, where multiple providers aim to co-provide services jointly and have to coordinate their activities on an equal footing. The specification of inter-organisational processes is a precondition for delivering advanced services in a cooperation of IT service providers. However, the existing ITSM frameworks fail to provide reference processes for scenarios beyond hierarchy. IT providers are left in the lurch with the nontrivial task of defining concise, yet unambigious specifications of inter-organisational ITSM processes as a basis for their cooperation. In order to be able to concentrate on the challenges of inter-organizational ITSM scenarios not covered by existing frameworks, this thesis is focused on the so-called class of Concatenated Services, i.e. services provided as a sequence of partial services at the same technical layer by a set of independent providers. In contrast to well-known scenarios, like IP Peering and Transit between Autonomous Systems in the Internet, Concatenated Services are offered with tight end-to-end service quality guarantees and managed according to the best practices of service orientation. In the first part of the thesis, a thorough analysis of management challenges based on real scenarios is given and specific requirements for the definition of ITSM processes for Concatenated Services are derived which are used for a review of related work. The concept of Coordination Patterns is introduced as a means of categorisation of the numerous types of provider cooperation. Even though quite a lot of research has been performed in the areas of ITSM on the one hand and on information and process modelling languages on the other hand, the application of general-purpose languages on the definition of inter-organisational ITSM processes is barely covered. To address this issue, the new method ITSMCooP (ITSM Processes for Cooperating Providers) is presented in the main part. Based on the process modelling language BPMN and the Shared Information/Data Model (SID), the method consists of a collection of modeling conventions and recommendations, covering all relevant aspects in the the specfication of interorganisational processes. A top-down modeling procedure guides the utilisation of ITSMCooP, considering the incorporation of both reference processes from ITSM frameworks and Coordination Patterns. The thesis concludes with an application of ITSMCooP to a complex scenario.