The purpose of including an executive summary in a marketing plan is to introduce the company and explain all the key elements of the plan in a shorter form. Anyone reading this summary will get a firm understanding of all aspects of the business; such a summary is perfect for those who aren't able to read the entire plan. It's always a good idea to prepare the executive summary last so all important details from the marketing plan can be included. Each section should be clearly marked in whichever order you think fits best with your company's mission and goals.