Strategic Planning - Get Input From All Levels

Many times strategic planning only includes the people at the very top.
The problem with this is that according to the saying
"People at the top see the big picture, but the people at the bottom see the problems"
When a company has problems at the bottom, it keeps the strategic plan from having those transformational changes.
The workplace culture doesn't improve, buy-in doesn't happen, the discussions/brainstorming/problem solving just doesn't happen at the levels that it should.
I am not saying that everyone is involved in making the plan/goals/initiatives, but I am saying that give everyone a chance to give input.