Headteachers are trialling a replacement for the axed Ofsted self- evaluation form (SEF).
Education secretary Michael Gove scrapped the "bureaucratic" SEF, which makes a major contribution to inspectors' judgment of a school, last year because it was too "time-consuming".
But heads still want a document that highlights the strengths and weaknesses of their school, according to the Association of School and College Leaders (ASCL).
Inspection specialists at ASCL have developed their own version of the SEF, which is currently being tested by heads. A final version will be ready in the autumn term.
The SEF, introduced in 2005, can be more than 60 pages long for all-through schools. It is often 50 pages for secondaries, but can run to well over 100 pages once completed.
It asks teachers and heads to collect and verify facts and figures about their school in preparation for their Ofsted inspection.
The SEF was never compulsory, but inspectors used it to assess schools. After the form is discontinued in September, heads will still have to show evidence of self-evaluation.
The ASCL version, developed with the help of educational consultant Tony Thornley, is more flexible in form and content.
"This will not be like the SEF, which was very prescriptive," ASCL general secretary Brian Lightman said. "Heads found that to be very much a form-filling exercise."
"But it was quite clear our members wanted something in its place. Self-evaluation is now a key part of their job. Heads will still have to demonstrate evidence about their school to Ofsted."
ASCL Ofsted specialist Jan Webber said: "Some members were upset the SEF was going and asked what they could do instead.
"We are providing guidance, and a writing frame or format which follows the categories of the new Ofsted framework.
"There is scope for schools to put in more details if they want and to adapt it. It's not as bureaucratic as the SEF."