EST, or Estimation, is a process used to make an educated guess about a quantity or value when exact data is unavailable. It involves using available information, experience, and mathematical techniques to arrive at a reasonable approximation. This method is commonly applied in various fields, including project management, finance, and engineering. In project management, for example, EST helps teams predict the time and resources needed to complete tasks. By estimating costs and durations, managers can allocate resources effectively and set realistic deadlines. Overall, EST is a valuable tool for decision-making and planning in uncertain situations.