What is a RACI matrix and how do you build one that works?

The retro line everyone has heard: "I thought Tom had it." The task was discussed in three meetings, mentioned in two threads, and done by nobody. That is the exact failure the RACI matrix exists to prevent, with a grid small enough to fit on one slide.

The four letters

• R, Responsible does the work. Hands on keyboard, builds the thing. At least one per task.
• A, Accountable owns the outcome. Signs off, answers for it. Exactly one per task, never two.
• C, Consulted gives input before the work happens. A two-way conversation with someone whose expertise shapes the deliverable.
• I, Informed hears about the result after. One-way, no reply expected.

Two letters carry the task; two letters watch it. Most RACI failures come from mixing those pairs up.

A worked example

Tasks down, people across, one letter per cell:

Read a row to see how one task gets done. Read a column to see one person's load: an analyst column full of R is a bottleneck warning, a sponsor column full of C is a calendar problem.

The golden rules

1. Exactly one A per task. Shared ownership is no ownership.
2. Every task has an R. No R means the task will not happen, however many people discussed it.
3. A can also be R. Normal on small teams. Still one A.
4. Every C is expensive. A C is a meeting, a review loop, a wait. Challenge each one: would their input actually change the deliverable?

Smells to fix

• Two A cells on one row. Split the task or pick an owner.
• A row of only C. Everyone talks about the task, nobody does it. This is the "whose job was that?" row.
• I everywhere. A status-noise generator. Trim the audience; the ones who care will ask.

How to build one

1. Tasks down. Rows are deliverables ("draft the KPI definitions"), not job titles or project phases.
2. People across. Columns are roles, not the whole org chart.
3. Place the A first. Ownership is the decision that matters; R, C and I follow from it.

Then walk the grid once against the rules above. The whole exercise takes twenty minutes and saves the retro.

The takeaway

One A per row, at least one R, and every C must earn its meeting. The print-ready PDF above fits the four letters, the rules, the example grid and the smells on a single page you can bring to your next kickoff.