© Scandinavian Journal of Information Systems, 1996, 8(1):89–118 Abstract The focus of this research is on the appropri- ateness of the Substance-Theory-Oriented approach to the implementation of an Organ- izational Decision Support Systems in a small company. An ODSS is a general-purpose, multiple-user, large-scale system that has a relatively definite, continuous and organized position in the planning and decision making processes of an organization and which are designed for a variety of organizational deci- sions. We constructively show by means of a real case how the substance theories can be used to determine the actual contents of an ODSS. We have tested design guidelines and implementation strategies that can be ex- ploited in small business companies in gener- al. The main idea of the proposed approach is that the managerial substance-theories should be utilized at each phase of the devel- opment process, beginning from the initial problem review and ending with the use and the evolution of the developed system. It is assumed that only these theories can direct the design and development process in the right direction and carry appropriate infor- mation and knowledge into the organization. By applying the proposed approach small companies are able to decide the contents of an ODSS, manage the development process, increase their managerial knowledge, and fi- nally, make more structured and better deci- sions. Key words: organizational decision support system, small company, dss development methodology An Experiment to Apply Some Substance-Theories to the Development of an ODSS in a Small Company Hannu Kivijärvi and Markku Kuula Helsinki School of Economics and Business Administration, Runeberginkatu 14-16, SF-00100 Helsinki, Finland