In business and engineering, new product development (NPD) covers the complete process of bringing a new product to market. New product development is described in the literature[which?] as the transformation of a market opportunity into a product available for sale. The product can be tangible (something physical which one can touch) or intangible (like a service, experience, or belief). A good understanding of customer needs and wants, of the competitive environment and of the nature of the market represents the top required factor for the success of a new product. Cost, time and quality are the main variables that drive customer needs. Aiming at these three variables, companies develop continuous practices and strategies to better satisfy customer requirements and to increase their own market share by a regular development of new products.[citation needed] There are many uncertainties and challenges which companies must face throughout the process. The use of best practices and the elimination of barriers to communication are the main concerns for the management of the NPD process.[citation needed]