What I Learn When I Failed a Project

"Carpool" is a simple desktop application that generates carpooling table from worker time schedules and car ownership information. After 2 month the client wanted to persist, edit, delete and update workers in the Application. The data should has been saved in the cloud and accessible from every device. This changed everything and my focus shifted from what Client really needed to what was possible to implement. We lost a lot of time and trust of our client. We started with no plan, then we wrote our tasks in Excel Sheet.