The SOSTAC Marketing Planning Model is a four-stage marketing planning process that helps businesses identify their marketing objectives, develop their strategies and prepare the budget. The SOSTAC Marketing Planning Model is based on the assumption that all business decisions are made through three different perspectives: the marketer, the customer and the company. The model is made up of four stages: The first stage is to define your marketing objectives. The second stage consists of developing strategies for achieving your marketing objectives. The third stage is to prepare your budget for achieving your strategies. Finally, in the fourth stage, you need to monitor and evaluate your strategy to find out if it’s working or not.