Responsibility Assignment Matrix (RAM)

The Responsibility Assignment Matrix (RAM) sits at the intersection of the Work Breakdown Structure and the Organisational Breakdown Structure. Each row is a WBS element; each column is an OBS unit; each cell records the responsibility relationship — typically using a RACI scheme (Responsible, Accountable, Consulted, Informed) or the simpler R/A coding used in EVMS documentation. A properly populated RAM identifies, for every scope element, exactly one accountable manager and any supporting roles. It is the canonical answer to 'who does what' on the programme.

The RAM has a specific contractual role in Earned Value Management. The intersections marked as 'accountable' on the matrix define the Control Accounts — the units at which budget is authorised, performance is measured, and variances are managed. The control account manager named in the RAM owns the control account plan, signs off the time-phased budget, and is the accountable individual for any variance analysis or recovery planning. Where the RAM is missing or ambiguous, the EVM system has no defensible chain of accountability and the variance reports become noise.

Beyond EVM, the RAM is the tool that surfaces the structural problems in how a programme is organised. Rows with no 'A' (no-one accountable) reveal coverage gaps; rows with multiple 'A's (more than one person accountable) reveal contested ownership. Columns that are mostly 'C' or 'I' reveal stakeholders who think they are managing the work but in reality have no executive role. On JV-delivered or partnered programmes, working through the RAM line by line with the parties together is one of the most reliably useful exercises in early mobilisation — it forces the conversations that get otherwise deferred until something goes wrong.