Imagine a team agrees that sales are disappointing. One person wants a new campaign; another wants a lower price. They agree on the symptom, but may be solving different problems.
The challenge may be a customer need the organization cannot meet, a capability it has not built, or a set of commitments that pull in different directions. Until that is named, proposals can sound equally attractive because no one has said what they must solve.
In Good Strategy/Bad Strategy, Richard Rumelt puts diagnosis before action. That order matters: a diagnosis narrows the field. It gives a team a reason to choose one route and reject others. It also keeps a strategy from becoming a wish list with an impressive title.
Try writing a one-sentence description of the obstacle, without naming the solution. Then ask what evidence supports it and what evidence would change the diagnosis.
Source: Build a Strategy that Addresses Your Gnarliest Challenges