Title: Purchasing Process of Services: A Study of the Purchasing Process of HumanResource (HR) services Background: The rise in competition among organizations continues to increase. The rise in globalization, outsourcing and continuous pressure from customers have been the source for the increase in competition. Additionally, the instability in various industries is leading to high competition among firms. The purchasing of professional services is vital to organizations. Contemporary organizations spend a huge portion of their resources on the purchasing of professional services. The proper purchase of professional services can lead to cost saving and competitive advantage for companies or organizations. Research Questions:  How can the various purchasing models be used to develop a process for professional HR service purchasing? What are the factors involved in developing a process for the purchasing of professional HR services Purpose: The purpose of this thesis is to develop a purchasing process for the purchasing of professional HR services. It takes into consideration the various classifications models of purchasing and the factors involved in the purchasing of services in order to develop a purchasing process for professional HR services. Method: Through a qualitative case study, the thesis gathered empirical data and used the deductive scientific approach to building a foundation of theory. Additionally, pattern matching was used to analyze both the theory and empirical data. Conclusion: The thesis developed a new classification model for HR services which resulted in the development of a new purchasing process that takes into consideration the classification of services and integrates the effects of the classification in the purchasing process. Additionally, the thesis discovered that personal relationship, clarity of problem and solution, specification of supplier’s inputs, specification of supplier’s throughputs or processes, specification of supplier’s output and specification of supplier’s outcome and the characteristics of service are factors involved in the development of a purchasing process forHR Services. Keywords: Professional Human Resource Services, Categorization of service, PurchasingModels, Service Purchasing Process