Problem statement: Organisations need real estate to enable them to perform their activities effectively and efficiently in a safe, protected and pleasurable environment. Typically, large organisations use many buildings to perform their activities. The relationship between a building (supply) and its users (demand) is constantly changing. This change is fuelled by technology and a host of economic and cultural trends. Because the supply - demand is changing continuously, most of the time there is a mismatch between what a building can offer and what an organisation requires. Therefore, one of the biggest challenges in Corporate Real Estate Management is reducing the gap between the high speed of business and the slow speed of real estate, i.e. between the so-called dynamic real estate demand and relatively static real estate supply. Research objective: Based on the objective of Corporate Real Estate Management, the research objective of this graduation work is to develop and present knowledge of how the physical resource can be enhanced by implementing ‘Office as a Service’. Because the mismatch is dynamic and will change frequently, a strategic decision approach to managing the mismatch between the user organisation and the building is proposed in order to offer a suitable way of approaching these problems. Therefore the main research question is: “How can ‘Office as a Service’ be a strategic decision approach for an organization to optimize their physical resources in order to obtain maximum added value?” Research method: By conducting operational-empirical research, the research questions are answered. By means of operational research, a strategic decision approach is developed that can be used in the process of forming an accommodation strategy to align real estate to the needs of the core business. Empirical research was used to obtain input for the development of the operational model. This empirical research focused on the performance of ‘Office as a Service’ strategies in relation to both the presumed added values of real estate and the various typologies of occupier space demands. To obtain the required input, a method of a literature review, semi-structured interviews and a cross-case study was used. Key findings and conclusion: A strategic decision approach is developed based on the concept of a Multi-Criteria Decision Analysis (MCDA) model. The development of this Multi-Criteria Decision Analysis model integrates the decision-makers criteria, which are based on the presumed added values of real estate as well as the five typologies of occupier space demand, with the alternative ‘Office as a Service’ strategies. Based on the model of Den Heijer (2011) to assess the added value of real estate decisions regarding the four stakeholder perspectives with their corresponding presumed added values, eight added values divided over all four stakeholder perspectives can be related to the concept of ‘Office as a Service’. Next to the presumed added values of real estate which contribute to the strategic goals of an organization, an operational aspect is added to the decision-criteria taking into account five typologies of occupier space demand of an organisation. Based on the Core-Periphery operational real estate portfolio space model of Gibson and Lizieri (1999) in relation to the alternative ‘Office as a Service’ strategies this results in the following interpretation: a stepped ascending relationship where the increase of flexibility is answered by a more external ‘Office as a Service’ strategy.