In business and project management, a responsibility assignment matrix (RAM), also known as RACI matrix () or linear responsibility chart (LRC), is a model that describes the participation by various roles in completing tasks or deliverables for a project or business process. RACI is an acronym derived from the four key responsibilities most typically used: responsible, accountable, consulted, and informed. It is used for clarifying and defining roles and responsibilities in cross-functional or departmental projects and processes. There are a number of alternatives to the RACI model.