The introduction of Office for Standards in Education inspections in 1993 was a watershed, not only for teachers but for inspectors, too.
When OFSTED announced that contracts for school inspections would be awarded competitively, a multi-million pound industry sprang from nowhere. With the contract to inspect just one school earning as much as Pounds 26,000, there was a huge incentive for former civil servants to become thrusting entrepreneurs.
"At first, primary inspectors basically got the prices they asked for, " says an OFSTED spokesman. "They just weren't facing fierce competition."
But it wasn't long before hundreds of contractors were competing for a slice of the enormous cake on offer. Over the current financial year the budget for school and nursery inspections stands at Pounds 118 million.
Back in 1994-95 OFSTED employed 70 separate contractors; today it has 240. And while 78 per cent of the earliest inspections were carried out by local education authorities and 22 per cent by independent teams, last year 73 per cent of primary inspections were carried out by independents, and just 27 per cent by LEAs.
One of the biggest contractors is the Centre for British Teachers Education Services of Reading, which bids for inspections amid a whole range of other services. Although strictly a non-profit-making organisation, CfBT is quite happy to generate a surplus on the contracts it wins.
Neil McIntosh, chief executive of the company, says that up to 1991, when the organisation worked solely overseas, it had a turnover of Pounds 8m. In 1993 CfBT began offering its services to British education, and today its overall turnover stands at almost Pounds 40m.
CfBT has been so successful that OFSTED, fearing that the market could become "unhealthy", ruled before the start of the current year that no one company could win more than 10 per cent of the inspection contracts awarded.
And all this healthy competition has had a knock-on effect for Britain's 9,000 or so inspectors.
"There's been a huge spin-off," says the OFSTED spokesman with pride. "There's a huge pool of people who, when not working for us, are selling themselves to schools to do pre-OFSTED consultation and advice - and there's a lot of money being spent by schools on consultants."