The marketing planning (concretized in the marketing plan) is an essential organizational activity, considering the hostile and complex competitive business environment. Our ability and skills to perform profitable sales are affected by hundreds of internal and external factors that interact in a difficult way to evaluate. A marketing manager must understand and build an image upon these variables and their interactions, and must take rational decisions.
I once sat in a meeting of project and business updates and suddenly one of the directors said, actually with all that we have now we can be in the medical device market. Violaaa!!! This medical device company used to service government hospitals and they have all the equipments. It's just that they never thought of going direct to the hospitals and take the lion share of the business. In that meeting, after going through the company yearly updates, this "innovation" came instantaneously and the next year they are pitching about it to the government hospitals directly.