The aim of this study is to construct a fundamental theory of planning. The main subject is not only theory in planning but theory as planning.

In the first part (from chapter 1 to chapter 6), a mathematical formulation of planning and client's (people's) will is given. And some logical facts that exclude some based view from our common sence are derived from model PPS.

In chpater 8, an extension of formulation (model MPPS) is given.And some properties of planning is shown.

In the last part (chapter 8 and 9), the largest model (recursive planning process system RPPS) is formulated. By this model, one metatheorem, that asserts the fact what almighty routine method does not exist, is proved.

Some available results are shown as theorem in each chapter, and as application of theory in chapter 6. Outline of this paper is showned in following chart.