This project contains directory structure which we use at FEDEVEL for projects, however, feel free to use it in your company or for your own projects. You can always find the most recent version of this structure at https://github.com/FEDEVEL/fedevel-project-directory-template
Each directory and subdirectory has a readme.txt file with detailed explanation about what files should be placed there.
To start using this structure, simply press "Clone or download" -> "Download ZIP". Unpack the zip and place the main directories on your server(s).
You may want to place "Design Files" & "Released Files" directory on your server which is regularly backed up. "Project Files" are not required to be backed up (if something happen, you can usually re-download all the documents).