Other thing I don't know if can agree is that program's author has complete theory about his program. I think that is oversimplification. I think that often pr

Other thing I don't know if can agree is that program's author has complete theory about his program. I think that is oversimplification. I think that often program authors don't know what they are doing. Quite often somebody new who comes to the project has more insights about the project than original authors. Because: 1. the author can be biased (that's why we need code reviews) 2. the author can be less experienced has less programming skills, than a new person on the board. 3. the author simply lost his fresh eye for the program etc.