Peak capacity refers to the maximum level of output or performance that a system, machine or organization can achieve. Synonyms for peak capacity include peak performance, maximum capacity, optimal output, top efficiency, full potential, ultimate productivity, highest level of functionality, and best performance level. These terms can be used interchangeably depending on the context in which they are used. For instance, a manufacturing company may use peak capacity to refer to the maximum level of production that their machines can yield in a given time. Similarly, a sports coach may use peak performance to refer to the highest level of performance that an athlete can achieve in a game.