The Responsibility Assignment Matrix (RAM) is a graphic representation that reflects the integration of project participants such as work teams, subcontractors, and internal organizations with individual Contract Work Breakdown Structure (CWBS) elements to form Control Accounts (CA).
The RAM shows the WBS on one axis and the Organizational Breakdown Structure (OBS) on the other. The intersection of these axes designates who is responsible for what products or services and is known as the control account. After detail planning is completed, the RAM is dollarized and then depicts the total budget for each CWBS element and the total budget for each respective control account manager.
The RAM not only helps ensure that someone is responsible for all contractual work scope; it also verifies that there is only one individual assigned with responsibility for that work. When developing a RAM, the level of the organization and the CWBS level should not be driven so low that costs to maintain the EVMS become excessive. Finding the most optimum balance of cost, schedule, and technical visibility generally provides the best definition for the control account.
The RAM is always a part of the data call information requested for EVMS reviews . It is a good document to easily determine the value of control accounts as well as view them by organization/function and Contract Work Breakdown Structure (CWBS) element.
Traceability between the RAM and other program documentation must always be maintained. The RAM is updated whenever there is a change to control account budgets. The budget for a control account shown on the RAM should always equal the budget on the work authorization document for that control account. The sum of all budgets identified to control accounts on the RAM should also equal the amount of distributed budget shown in the Contract Budget Base Log. The sum of the control account budgets plus Undistributed Budget equals the Performance Measurement Baseline (PMB). Finally, these budgets will trace to the Contract Performance Report (CPR) or the Integrated Program Management Report (IPMR) in Formats 1 and 2.
1 Resources: Basic Concepts of Earned Value Management (EVM)