Lean startup is a methodology for developing businesses and products that aims to shorten product development cycles and rapidly discover if a proposed business model is viable; this is achieved by adopting a combination of business-hypothesis-driven experimentation, iterative product releases, and validated learning. Lean startup is a methodology for developing businesses and products that aims to shorten product development cycles and rapidly discover if a proposed business model is viable; this is achieved by adopting a combination of business-hypothesis-driven experimentation, iterative product releases, and validated learning. Central to the lean startup methodology is the assumption that when startup companies invest their time into iteratively building products or services to meet the needs of early customers, the company can reduce market risks and sidestep the need for large amounts of initial project funding and expensive product launches and failures. Similar to the precepts of lean manufacturing and lean software development, the lean startup methodology seeks to eliminate wasteful practices and increase value-producing practices during the earliest phases of a company so that the company can have a better chance of success without requiring large amounts of outside funding, elaborate business plans, or a perfect product. Customer feedback during the development of products or services is integral to the lean startup process, and ensures that the company does not invest time designing features or services that consumers do not want. This is done primarily through two processes, using key performance indicators and a continuous deployment process. When a startup company cannot afford to have its entire investment depend upon the success of a single product or service, the lean startup methodology proposes that by releasing a minimum viable product that is not yet finalized, the company can then make use of customer feedback to help further tailor the product or service to the specific needs of its customers. The lean startup methodology asserts that the 'lean has nothing to do with how much money a company raises'; rather it has everything to do with assessing the specific demands of consumers and how to meet that demand using the least amount of resources possible. Use of the word lean to describe the streamlined production system of lean manufacturing was popularized by the 1990 book The Machine That Changed the World. The Toyota Production System pioneered by Taiichi Ohno combined flow principles that had been used by Henry Ford since the early 1900s with innovations such as the TWI programs introduced to Japan in 1951.