Performance assessment is a review of how well an individual, service, organisation or system undertakes a defined task. Many criteria could be used to specify more precisely what is meant by ‘how well’. These criteria might include: effectiveness in terms of delivering a particular set of services or belter quality care (see below); improving outcomes for people who use services (see above); efficiency (e.g. as measured in an economic evaluation – see above); equity (see above); empowering individuals to take more control over their lives; protecting vulnerable individuals from abuse or discrimination; improving social inclusion; promoting social solidarity; and ensuring longer-term system sustainability.

Assessment of performance could be undertaken for a host of reasons: to inform a contractual agreement or monitor contract compliance; for inspection purposes; to guide local purchasing or commissioning decisions; to inform broader strategic policy discussions; or so that people who use services or their families can make judgements. Some performance assessment will therefore be quite formal and structured, while some will be relatively informal. Some performance criteria might be objectively assessed while others will rely on more subjective views.