As a project manager, as a product manager, and as a consultant, the thing that often frustrates me is the desire to go full steam ahead without a shared understanding of what it actually is that we’re supposed to be doing.

Dorian Taylor, in a wider-ranging piece about Agile, talks about this as conceptual integrity:

The one idea from the 1970s most conspicuously absent from Agile discourse is conceptual integrity. This—another contribution from Brooks—is roughly the state of having a unified mental model of both the project and the user, shared among all members of the team. Conceptual integrity makes the product both easier to develop and easier to use, because this integrity is communicated to both the development team and the user, through the product.

Without conceptual integrity, Brooks said, there will be as many mental models as there are people on the team. This state of affairs requires somebody to have the final say on strategic decisions. It furthermore requires this person to have diverse enough expertise to mentally circumscribe—and thus have a vision for—the entire project in every way that was important, even if not precisely down to the last line of code.

Source: Agile as Trauma | dorian taylor