Reading the Impact Matrix and cascade risk
How cascade risk is scored, what CRITICAL, MODERATE, and ISOLATED mean, and how to trace a delay back to its root cause.
What the matrix shows
The Impact Matrix lists every task with the complete set of work downstream of it. Not just the tasks linked to it directly, but everything those tasks feed, and onward to the end of the chain.
A task with two direct dependents that each feed four more is reported as affecting ten tasks, because that is what it affects. This is the number that matters when someone asks whether a slip is a problem.
The three cascade scores
CRITICAL means three or more tasks are downstream. MODERATE means one or two. ISOLATED means none.
Each score comes with a recommended action attached: protect a CRITICAL task, because any slip cascades to a named number of tasks; monitor a MODERATE one; manage an ISOLATED one within its own group.
The point is triage. Not every slip deserves the same reaction, and the matrix tells you which ones do before you spend a meeting deciding.
Tracing a delay to its cause
When a task has moved, the matrix records which upstream task pushed it, and can walk that trail back through the network.
That turns "integration moved three weeks" into the chain that produced it: the vendor delivery slipped, which pushed data mapping, which pushed integration. It is the version that is useful in a status meeting, because it names where to intervene.
Which plans have the Impact Matrix
The Impact Matrix is available on Standard and above.
The method behind this
Total float and free float: the difference that matters →
Two different kinds of slack, why confusing them causes missed dates, and a worked example where a task has eight days of one and none of the other.