In information systems, data are processed in various stages, and at every stage value is added in order to make the data useful for end users. Experts from different fields can assist these value-adding processes in various ways. This article discusses a theoretical model for determination of value-added processes in information systems. In this model, vital elements of every information system, that is, its goals, users, services and data, form a three-dimensional space. Each of these dimensions and the possible processes to add value in each dimension are discussed.