Measuring Time
数量经济学Earned Value Management (EVM) is a project management technique for measuring project progress in terms of cost, schedule and scope, and has developed into a very effective way to uncover performance problems at an early and correctible stage in any given project. From its earliest days as a financial analysis tool in the US in the early 1960 s, it steadily grew in use through the US Department of Defense until it was made the standard measurement for all DoD, NASA, and Department of Energy projects, and was widely adopted by p