"I would pick a previous project that failed because of the lack of prioritization. At the onset, leadership told us that this was going to be an open-ended side project. A lot of creative ideas were thrown around and we tried a couple of them. I would assign team members tasks, but those tasks kept getting pushed down because we had more time-sensitive projects. After quite a few months, it finally got shut down.
In retrospect, I should have put my foot down at the beginning and asked for an ROI analysis to see if it was worth starting the project at all. There was no business case, no clear objectives. The problem was that I was too new to the company and I didn't feel very confident in asserting myself. I've since learned to be bolder in disagreeing with leadership, as long as I'm able to use data and facts to support my case."