This RACI is a powerful tool for clarifying individual or group roles for each task in a project or business process and developing a simple language for discussing roles and responsibilities within an organization. RACI, first introduced in the 1950s as the Decision Rights Matrix, is also known as Responsibility Charting. There are also RACI variants, such as RASCI, ARCI, and DACI. It is the only project management tool that addresses the issue of people and roles. The RACI matrix model is now used by many businesses, from eBay to Amazon and from Proctor and Gamble to the United States Department of Defense.