He has testified regarding engineering design factors, manufacturing flaws, operational factors, human factors and safety. He has been qualified as an expert witness in cases regarding guarding, warnings, control systems and predictable use and misuse. As president and founder of Mizen Engineering Company, Inc. in 1971, Mr. Mizen has designed and built special equipment and computer based control systems for use in the manufacture of a wide variety of products. His work has included equipment that assembles small parts, machines valve bodies, and cleans parts use in compressors. He has studied manufacturing systems for client companies and prepared engineering and economic studies pertaining to equipment. Mr. Mizen has been extensively involved with computers. He has prepared mathematical simulations of dynamic systems, with particular emphasis on vehicle dynamics and off-road mobility. His work has involved designing and building computer controlled equipment that utilized stored programs and interrupt controlled remote stations.

From 1966 to 1971 Mr. Mizen was responsible for developing packaging machinery and for developing numerically controlled manufacturing processes. Particular emphasis was given to safety, speed of operation, and cost economy. From 1961 to 1966 Mr. Mizen was a Research Engineer in the Vehicle Dynamics Department of Cornell Laboratory. Projects for which he was responsible concerned ride and steering problems associated with land vehicles. He developed the Man Amplifier, a machine that fits over a person and follows his natural body motions. As a result of these projects he has become experienced in vehicle dynamics and vehicle response, and in applying engineering principles to the human body. Mr. Mizen was a designer for front-end loaders from 1955 through 1957. He was assigned responsibilty for engine installation. He was a Machinist and Tool and Die Maker in the Milwaukee area prior to 1955.