Simultaneous discoveries occasionally happen. In chemistry Scheele, Preistley and Lavoisier can all claim to have discovered Oxygen.
Even so, I was surprised to discover, thanks to the research my ISBS1 students were doing last spring for their project management books, that the so called GANTT chart should maybe be called the ADAMIECKI chart.
Henry Gantt only started publishing his work in 1910. Karol Adamiecki began publishing his in 1898. As often happened then, this pioneering management researcher started life as an engineer in St Petersburg (Poland as such did not actually exist until 1918) and then moved to Warsaw, where he began lecturing at the Warsaw Polytechnic.
My grandfather graduated from Warsaw Polytechnic round about that time. He was an engineer. I wish I could have asked him whether he had ever used the harmonogram chart.