This guide to the development of line managers stresses the idea that the developmental process which any manager undergoes is the product of his own activity and should be treated as a continuous function. Major line functions, managerial attributes and characteristics, presupervisory selection, and preparation through trainee, temporary foremen, classroom, or seminar activities are covered in the first few chapters. Differing managerial styles, the transition involved in becoming a manager, and special problems and educational needs of middle management, are next examined, followed by criteria for seeking out potential executives. The executive role and its implications for development are also discussed, together with the task of effectively phasing out and replacing a high executive. Finally methods are described for appraising lower echelon managers, conducting personnel research, formal and informal training, and consultation by specialists. (ly)