High Quality Content by WIKIPEDIA articles! Theory Z is a name applied to three distinctly different psychological theories. One was developed by Abraham H. Maslow in his paper Theory Z and the other is Dr. William Ouchi`s so-called "Japanese Management" style popularized during the Asian economic boom of the 1980s. The third was developed by W. J. Reddin in Managerial Effectiveness (19 Situation guides) man: