Nordstrom’s employee handbook contains just one instructiuon.
“Use your best judgement.”
The temptation in organizations, especially large ones, is for methods and practices to be applied across the whole gamut of projects regardless of their requirements or the background and experience of the people involved. Ken Schwaber’s Caveat Emptor on this approach.
In terms of agile software development there have been several people with ideas on what best judgement might look like in terms of a plan driven/agile mix.
Balancing Agility and Discipline: A Guide for the Perplexed – Barry Boehm and Richard Turner