The school inspectorate in England is known as “Ofsted” which stems from the time when the body responsible for school inspection was called the (Office for Standards in Education). Originally its focus was schools but in 2007 the remit of Ofsted expanded to include childcare provision and learning and skills provision for all ages as well as school education and is now the Office for Standards in Education, Children’s Services and Skills, although the term “Ofsted” has remained. State maintained schools in England are required by law to be inspected and current regulations stipulate that from September 2009 all maintained schools must be inspected every 5 years. The functions of Ofsted are prescribed in Acts of Parliament and the mechanisms that Ofsted use to bring about its aims and functions are detailed in Ofsted publications.
You can download the paper on the conceptual model here.