I was doing my final design project in my FED class in NJIT, and it was a huge project that required a lot of work. To make story short, I had to design a gear a certain way in order to have the right mechanism later on, and I missed a small feature in the gear. In results of that, after three full days of designing the rest of the project I discovered that I had to fix that part before doing any mechanism. If I had a good initiating phase to know that every little feature is dependent on the old ones, I would have focused on each single feature instead of saying that I can change anything later on. At the end, I had to erase all what I did after that mistake and re do it again, which required double the work to meet the deadline.