The first thing you notice when you enter Wendy Davies' office is a map of the city dotted with colour-coded pins. Each pin - red for Year 7, blue for Year 8 etc - indicates the homes of her girls. Most of the 750 pupils are concentrated not in the comfortable suburb where Selly Park Technology College for Girls is situated but in deprived inner-city Balsall Heath, Sparkbrook and Small Heath.
You notice a different colour code when you look at her desk and see a clipboard holding a list of all Year 11 girls. Blue indicates they are on target to get the coveted five high-grade GCSEs; orange stands for a borderline case and black for those heading for failure.
Davies is interviewing all 130 girls sitting exams this summer. Although it is Friday, the process of cajoling, encouraging and arm-twisting to refocus the girls on the task in hand will go on all day and spill over to Saturday morning. Davies is on a personal mission because she has built her reputation, and that of Selly Park, on exam success. When she arrived in the 1980s, the school's O-level pass rate was 3 per cent. Last year it gained 62 per cent top-grade GCSEs or their GNVQ equivalent This year she aim to take it one or two percentage points higher.
Davies is an admirer of Kevin Satchwell, head of Telford Technology College 30 miles to the west, reputedly the most successful state school in the country with 100 per cent top grades.
But she believes his pupils have an advantage over hers. "Most of our key stage 2 results show girls at level 3, but Telford has mainly fives. Still, they are our target because if you don't aim high you can't achieve high."
Davies is an entrepreneurial head who has invested heavily in computers and industrial-standard machinery so that there are screens in every room and quiet working areas where girls can get on with their work.
She has co-opted the bosses of three big firms on to the governors so that Selly Park can benefit from the latest technological advice and some instant largesse: the food-processing machinery is state of the art and what the girls achieve in design and technology is displayed impressively on the corridors and classrooms.
The other display on the walls at Selly Park that you can't avoid is that crucial figure: 62 per cent. No one is allowed to forget their GCSE target for this year.