As a project is planned it is necessary to have a good understanding of the time and resources needed to complete the project. On small scale projects it is easy to rearrange these items to gain advantages. As projects become larger in size it is necessary to have well defined roles to maximize adherence to schedule. Items can no longer be moved as easily. For some people this difference in scale is hard to grasp.
If you have the opportunity to try the new Crest Vanilla Mint toothpaste, don't. It tastes like frosting.