After graduation in 1906 Coes started his career the industry at the Liquid Carbonic Company, producer of industrial gases. Next he worked for the Searchlight Gas Company of Chicago, and later for the Sentinel Manufacturing Company ofNew Haven, Connecticut. Subsequently, he worked as industrial engineer for Lockwood, Greene & Company and Gunn, Richards & Company. Later in the 1910s he started as Philadelphia Manager of Ford, Bacon & Davis,[6] where he eventually became partner in the firm.
^abASME,Mechanical Engineering,Vol. 81. 1959. p. 90
^Daniel A. Wren, (2015) "Implementing the Gantt chart in Europe and Britain: the contributions of Wallace Clark",Journal of Management History, Vol. 21 Issue: 3, pp.309-327,
^Charles M. Merrick,ASME Management Division history, 1886-1980, p. 64