Brocke, Henrik FinnHenrik FinnBrockeBrenner, WalterWalterBrennerUebernickel, FalkFalkUebernickel2023-04-132023-04-132011-01-07https://www.alexandria.unisg.ch/handle/20.500.14171/9463710.1109/HICSS.2011.134Whilst service providers of information technology (IT) seek to achieve cost-efficiency and optimization in request processing, customers increasingly demand flexibility and agility to align long lasting IT service relationships to changing requirements of their business processes. Customer individual adjustments of service agreements and changes in commitments of functionality and performance cause negotiation and service reengineering efforts. Amounts of service agreements and change requests impede the overview of currently valid commitments in service systems. In order to overcome these problems, this article proposes to customize service systems on demand only by selecting, parameterizing and arranging predefined and productized service propositions. A self-service reference model is introduced that allows the customer to continuously adjust service systems in their arrangements of committed IT services on demand. Its implementation as an online portal supports easy traceability of the current total of IT service commitments as well as consistency of additional service requests with the current service arrangement. Examples from its application in two major IT-projects illustrate the results.enCCIIMconference paper