Michael Wade explains the sidewalk rule and why we should build paths first.
Keeping things simple and action-oriented is difficult and yet if that orientation is not present from the start, it may be too late. Territory may already have been seized and boundaries drawn.

— The Sidewalk Rule 
In a recent project, I took the advice of another team when setting up a new project and categorising the work involved based on a template this team used. In doing so, I complicated the project before it even began. I should have built paths first before building sidewalks.