Benchmarking refers to the process of comparing the performance of an individual worker, service, organisation or system against an agreed standard. The criteria for making the comparison could therefore include any of the criteria discussed later in relation to performance assessment (effectiveness, efficiency etc.). The standard could be set externally, or could be defined by reference to the performance of other similar workers, services, organisations or systems (such as the mean level of performance, or third quartile level, etc.). The aim of benchmarking is to help a service, organisation or system to improve its performance.