In Part I we discuss the general background of problem-solving in organizations. We start by describing the characteristics and general setup of problem-solving projects, which aim to improve the performance of a certain business system on one or more performance indicators in the real world. We compare this with business research projects, which aim to develop general knowledge. We then discuss the characteristics of the methodology for business problem-solving presented in this handbook, and compare this with other problem-solving strategies. As design is a key activity in our approach, we provide some general design theory plus some theory on social system design. Finally, we discuss the various sources of knowledge to be used in business problem-solving, and the development of general design knowledge through scholarly research.