If your big project is successful, it will be because the assumptions it rested on were true. But when you start your project, you don’t know what is and is not true. Think of 4 factors in descending certainty: 1) Facts (we know what we know.) 2) Assumptions (we know what we think.) 3) Questions (we know what we don’t know.) 4) Surprises (we don’t know what we don’t know.) To “de-risk” your project, lay these out at the beginning of your project… and then drive each from uncertainty to certainty.
To see how this is done, view the video at Project De-risking with Minesweeper