RAID is an acronym that stands for Risks, Assumptions, Issues, and Dependencies, which are aspects of every project. A RAID Log tracks lists of these items and is used by a project manager to minimize the chances of negative events. Each RAID item in the RAID Log has a status, severity, and actions for particular people involved in the project. RAID project management techniques originate from the classic "waterfall model" project management approach that started in the 20th Century.