What supervisor in their right minds would take a complicated task that one analyst can do perfectly well, and assign it to a new analyst? Especially if the task involves a lot of frustrating back-and-forth between competing schedules, reconciling dates by hand. With one's shoulders hunched over the desk. And a pen clenched in one's fist. Like Bob Cratchett, only with better task lighting.
The only good reason I can think of, is if the other analyst secretly requested to be taken off that particular project. But I can't trick my coworker into admitting she did that, mwheh-heh.
It's okay. I had a talk with my supervisor on Friday. It wasn't pretty. I expressed my displeasure with the way the last two months went. She apologized but asked why I didn't come to her sooner. I said because I was afraid this wasn't fixable; that it was the status quo. She apologized again, but said it is the status quo. And she has it worse. So our talk about my job satisfaction turned into a talk about her job satisfaction.
Also, from her monologue, I came to the realization she just wants a secretary in this chair, not an analyst. It isn't the job I thought I was getting, plain and simple. So I'm exploring my options. But in the meantime I am doing exactly what she needs and doing the best work I can.
It's always possible things will improve. Shoot, at least we talked. The door is open now. And life is capricious.