The purpose of the thesis is to explore the design of a planning system applicable to any formal organization. To do this, issues which are related to planning systems of various types (corporate, voluntary, public) are examined in chapter I. In order to take these issues into account, the chapters II and III indicate that the concepts of system and of design should be better understood. This provides tentative guidelines for the design of systems applicable to the management of organizations (chapter IV). These first four chapters make up the first part of the thesis and provide a review of some of the basic concepts which are needed to formulate a planning system of the type envisaged. The second part of the thesis essentially describes t...