This book adopts the decision theoretic viewpoint in the organization design problems in management and organization theory. The first part considers a short-run adaptive process in the organization. The organization design is represented by a combination of the organization structure and the management system and constitutes a part of the sequential decision problem of the work. The second part considers the long-run adaptive process for modifying and improving the work. This process is formulated as a partially observable Markov decision process. The final part restates the theoretical results of the previous two parts as normative propositions on the efficient organization design. To test these propositions, the study focusses on the organization structures and the management systems of Japanese firms and obtains the data which support the author's theoretical propositions. This book provides a useful normative approach to organization design problems in management and organization theory.