As an author and a Systems Consultant, I am excited about the draft diagrammatical techniques described in this book. They are proving their worth in a troublesome area of systematic data processing: the analysis/definition of what a new or a converted system should do if it is to be of most value to the people who are paying for it. In writing this book, the author distinguishes the work of analysis (defining what the system 'will' do) from the work of design (defining 'how' it will do it), recognising that analysts often design and designers often do analysis. The author's idea of using draft hand drawn diagrams during the initial design of every stage of the system development is what is actually included in this book. All the examples of the diagrams shown are hand written. The system and its diagrams are based on a system developed by the author for a corporation. The discipline consists of an evolving set of techniques which have grown out of the success of structured analysis and the use of diagrams.