Its new document, based on criticism of the “sometimes traumatic” introduction of the new inspection system, says the present round of inspections are about accountability rather than school development. Instead it proposes a twin track approach with external inspections running alongside a continuing process of school self-review and evaluation.

The document also criticises the standard of some of the inspection teams. It says there are sometimes conflicts of interest, for example when local authority teams inspect schools in their own area. In one case a grant- maintained school was concerned when an LEA team was sent in soon after a bitter battle over opting out.

The SHA document also comments on the uneven quality of expertise and experience in many inspection teams and the varied interpretations teams have of Handbook and Framework criteria. It notes discrepancies between oral feedback and the written reports.

John Sutton, SHA’s general secretary, said: “The great weakness which has emerged from the first round of inspection is that it has been concerned solely with accountability. Inspectors have reported only on what they see over a very short period. What is needed is to link inspection with a continuous process of development and improvement.”

The union’s proposal to reform the four-yearly inspection cycle has support from Chris Woodhead, the chief inspector, and the Government. The Office for Standards in Education is now looking at either lengthening the interval or introducing lighter touch inspections for schools not causing concern.

SHA proposes that the school self-review and evaluation (SSRE) process should be an internal exercise led by staff and conducted according to OFSTED guidelines. The head should, each year, review the progress of the evaluation and the implementation of its associated action plan and the governors publish a report for parents and OFSTED. An external evaluator will be appointed from a list approved by OFSTED to monitor the school’s cycle of evaluation and development.

Inspections should take place in a cycle longer than five years and may vary for secondary, primary and special schools. SHA wants all inspectors to have regular training from OFSTED, and not just the registered inspectors as is the case at present. It also wants all teams to have someone with experience of senior management in secondary schools.

Mr Sutton believes the external inspections and moderators will act as a check for schools with weak managements.

The document says: “Historically, SSRE has not been done well in schools, but many secondary schools have in place, or are introducing, more efficient programmes and SHA firmly believes this process has achieved sufficient maturity for it to be universally adopted and developed as part of a quality assurance system. In time SHA believes primary and special schools will also be in a position to carry out self-evaluation.”

While drawing up the document, SHA members heard a catalogue of inspection horror stories. Schools can only challenge inspection reports on inaccuracies but a list of mistakes compiled by one head filled six A4 pages. In another school an inspector was heard offering a child a painkiller, but was stopped by a member of staff.