Despite being somewhat detached from the inventory management process, Marketing has an important part to play. The chapter sets out the key areas of understanding a customer’s requirements (using tools such as channel gap analysis), especially when it comes to new product development, providing a detailed plan for new product when manufacture is scheduled to begin and being able to provide a long-term forecast for product demand. The latter is especially important where capacity constraints begin to manifest themselves, as these could require action sooner rather than later. For the oil, gas and energy markets, the chapter discusses tools such as project data analysis to generate product-specific forecasts. The value of such tools goes beyond contributing to the inventory management process by providing a means of capturing an organisation’s knowledge and expertise.