Note---An Early Classic Misplaced: Ford W. Harris's Economic Order Quantity Model of 1915

The familiar square-root formula for the optimal economic order quantity was derived originally by Harris in 1915 (Harris, F. W. 1915. What quantity to make at once. The Library of Factory Management, Vol. V. Operation and Costs. A. W. Shaw Company, Chicago, 47--52.). Since all citations found to Harris's paper over the past 35 years are incorrect, it seems that no one has been able to locate the paper during this period. The paper's apparent misplacement probably stems from an inaccurate citation given by Raymond in 1931 (Raymond, F. E. 1931. Quantity and Economy in Manufacture. McGraw-Hill, New York.). Harris's paper exemplifies skillful presentation of the concepts of management science, and still merits reading. Today's researcher can learn much from Harris's modeling approach, and would do well to emulate his expositional clarity and motivational effectiveness.