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.
To make an effective plan, there is a famous rule called 4P's. Here, P's stand for Price, Product, Promotion and Placement. In this another P is added called People. Today while doing digital marketing or the traditional marketing one should understand people or the customers you are dealing with. It's important to figure out what is significant for the business, and later make a plan accordingly.