The problem and the solution. Decision making is a complex phenomenon, even when studied in relative isolation. Decisionmaker premises that influence the decision-making process are not fully understood. One solution for gaining further understanding of actual decision making in practice could be through longitudinal case studies of actual decision makers. This report is from a 4-year case study of a small business owner's decision making within the two core realms of his work-business operations and technical production. New insights about decision premises being both mediators and constraints in the process were revealed.