Andler formula (1929)
Kurt Andler published a derivation of the economic lot-size formula in 1929 in Rationalisierung der Fabrikation und optimale Losgroesse (Oldenbourg, Munich)[1]. In German-speaking operations research it is the Andlersche Losgroessenformel; the derivation is mathematically identical to Harris (1913) and Wilson (1934). The parallel discovery was missed by the English-language literature for decades.
Who was Kurt Andler
Andler was a German industrial engineer working in the rationalisierung movement (the German parallel to the US scientific-management tradition). His 1929 monograph derives the EOQ formula via straightforward calculus and gives worked numerical examples across several industries. The book was widely read in German manufacturing circles.
Why German literature uses "Andler"
In the postwar era, German operations-research textbooks consolidated on the Andler attribution because Andler’s book was in German and Harris’s 1913 Factory article was in English with limited circulation in central Europe. The result is a parallel naming tradition: English literature says "Wilson EOQ," German literature says "Andler-Formel"[2].
Priority and the limits of textbook history
Erlenkotter (1990) established that Harris (1913) precedes both Wilson (1934) and Andler (1929)[3]. The honest historical statement is: Harris derived it first; Andler derived it independently 16 years later; Wilson popularised it 21 years later; the formula belongs to the field, not to any one author.
What this means for citing in a board pack
Cite as "EOQ formula (Harris 1913; popularised by Wilson 1934)." If you’re writing for a German-speaking audience, "Andlersche Losgroessenformel (Andler 1929)" is the standard local convention. Either is defensible and accurate.