85) Discuss the contributions of Armand Feigenbaum to quality thinking. 86) Discuss the contributions of Philip Crosby to quality theory. 87) Explain the Taguchi concept of robust design. 88) Discuss the contributions of Stephen R. Covey to quality thinking. 89) Explain the concept of reengineering proposed by Michael Hammer and James Champy. 90) Identify and briefly discuss the core quality management content variables.