Over the last decade, insight has grown that between a pure product manufacturer and a pure service provider, various business model options exist, in which products and services are combined to varying degrees. This concept is described by the term Product--Service Systems (PSSs), which is the subject of a considerable amount of recent research attention. The overarching goal of the presented work is to analyze the business potential of a PSS from the point of view of a manufacturer of investment goods. The PSS research field is often criticized for lacking maturity and a coherent terminology. In this thesis, a theoretical foundation for PSS research is proposed, including a new PSS definition, representation scheme and typology. Moreover, Functional Hierarchy Modeling is presented, a theoretical framework that allows to represent the functions of an investment good on different levels of abstraction. Three complementary approaches for PSS ideation, that support manufacturers in identifying a broad set of PSS options, are proposed and illustrated.The second part of this dissertation presents a generic methodology to evaluate the business potential of a PSS. This methodology focuses on the innovation potential of a PSS in cost and value and allows to analyze the impact of risks and uncertainties. It is validated through itsapplication on five in-depth case studies, performed for Belgian industrial manufacturers. The business potential of a PSS is analyzed for a manufacturer of elevators, a provider of lighting control systems, a provider of fire detection systems, a developer of diamond polishing systems and a manufacturer of wind turbine gearboxes. <w:latentstyles deflockedstate="false" defunhidewhenused="true" <w:lsdexception="" locked="false" priority="0" semihidden="false"