Ordinary teams that do not clearly define roles will inevitably double work. Double work can happen for a couple reasons. Some teams plan for double work by assigning someone a job that they don’t trust them to do. When that person completes a task, someone else on the team checks their work and redoes it. This is a passive aggressive way to control a teammate with a severe cost in productivity and dignity. Unplanned double work also happens, often due to lack of communication. When teammates are unclear about ownership of specific responsibilities, they will inevitably work on the same project without communicating about it. In the end someone wasted their time.