Why is that? The intent was there; the energy was present; and ideas were flowing. That's the easy part _ coming up with the ideas. The success of your planning doesn't rest on the ideas, but rather, implementing those ideas. It's true, companies need to foster innovation in their business planning, but more importantly, they need to create a business environment that enables team members to execute these ideas with an "on_time, on_budget" mindset. That is where the work begins.
Any casual viewer of the BBC programme, Dragons Den will be aware of how easy it is for weaknesses or gaps to be identified. Depending upon the purpose of the plan, this may, or may not, prove to be critical. It is often easier to recognise such weaknesses and gaps, and be prepared to deal with them, either by noting them in the plan itself, or having appropriate answers available should the need arise.