Simplify the following text for a Grade 10 native English-speaking person.
Original: In his ` Classification of Design ' ( 1976 ) , Gorb divided design into three different classes ; design management operates in and across all three categories :
Simplified: Peter Gorb , a Life Fellow of the Design Management Institute and a long time Fellow of the RSA , has led the Design Management department for over 20 years and is seen as a godfather for design management . He defined his design reclassification in 1976 , and published his book Design and its Use by Managers two years later .