The First What?
The first business computer. The first Systems Analyst. As a curator, I always demur when asked "what was the first....? There's no end to it, and technology does not proceed that way. A new technology does not suddenly appear in fully functional form; it "eases up" to functionality. At some point you say "it's ready." But it probably isn't ready, but only after some tweaking, redesign, and refinement does it take a form that we recognize.
Appropo of all this, take a look at this obituary of David Caminer. I don't think the term "Systems Analyst" had been coined yet, so it is not quite right to call him the first. But he was a pioneer. And the LEO deserves more credit.