I know that you’ll be thinking: “What anorak remembers the contents of specific circulars?” Our filing system makes retrieval of past circulars a challenge and usually I give up and phone a friend, so my recollection of their content is near impossible. But this one was different. It contained a clear, concise, unambiguous table on minimum staffing standards in primary schools, so that all that was required for annual configuration of classes was a bit of manoeuvring and persuasion for a day or two about composite classes and Bob was your uncle.

Now, at a time when unprecedented budgetary restraints strangle at birth any possibility of a generous allocation of teachers, the same exercise takes several weeks and provokes invocation of dire consequences upon persons of indeterminate parentage who exist solely to make my life more difficult. Forget clear, concise and unambiguous and imagine gobbledy-gook generated by a computer programme, which spews out scores of possible class configurations, most of which are unworkable, and identifies an optimum.

One man’s optimum (to be more accurate, a retired secondary head’s and a statistician’s optimum) has proved to be the primary heads’ logistical workload.

I believe this inflexible, technological approach to determining the number of classes in primary schools was introduced to prevent headteachers from keeping fictional or ghost pupils on the roll and wangling an extra teacher out of the system. As if! The resulting reduced capacity across all classes is more likely to create difficulties in accommodating unforeseen new admissions, arising either from moves into the school zone or from placing requests under The Parents’ Charter.

Combined with this exercise is the one on the staffing allocation, the unique formula for which is understood by one individual in our authority, now retired. Account has been taken of reduced class contact time so that timetabling and organisation of relief teachers can proceed at the eleventh hour.

No allocation of reduced class contact is given to class-committed depute heads and principal teachers, as they will have management time, but probationer teachers must have that time added to their day and a half of training each week. Am I missing something or has the world gone mad?

Having a probationer teacher on the staff offers a part-solution to the nightmare of timetabling for reduced contact time, as it frees up someone else to cover classes, but it is nowhere near sufficient.

Even with the deployment of visiting teachers of expressive arts, we still have to scrabble around for relief teachers who are willing to commit to what is effectively a job as visiting teacher to provide “McCrone cover”.

There may be a pool of “well qualified and willing teachers who sit at home waiting for the call that never comes” (TESS, August 18), but my experience has been that the offer of a year’s work on a day and a half each week does not appeal to large numbers of relief teachers because it involves them in the planning of learning and teaching, assessment of pupil progress, record-keeping and report writing, instead of babysitting a class now and then for the same money and a fraction of the effort.

Up to now parents have been remarkably tolerant of the negative impact on continuity of their children’s education caused by a succession of different teachers and they seem not to be alerted to the occasional sound of a staffing barrel being scraped. I wonder how long we’ll get away with it.

Joan Fenton is headteacher of Dyce Primary in Aberdeen