In your business, you have products, services, and activities that are peripheral to your business - the outer walls of sales and revenues - and you have products and services that are central - your citadel business activities that represent the major sources of your profits.
Your core business can be thought as your “citadel”. It represents the product or service lines that are vital for your survival. They must be protected at all costs. As long as you remain strong in these areas, you can withstand market fluctuations and sales declines. You must therefore guard and protect them against all competitor.
