Solving the annual Timetable Puzzle

Dr Ian Waite is responsible for the mammoth task of creating our boys’ timetables each year.

It’s a mind-boggling task when you consider the number of students, the number of lessons, the number of teachers and the number of rooms. How can all this be considered and clashes avoided? Well, it is possible, and Dr Ian Waite, Data Analysist is the man for the job! He kindly took some time out of his very busy schedule getting 2023 ready, to share the process of creating a timetable.

Dr Ian Waite

The Senior School timetable is incredibly complex and, as a result, the process commences early in Term 3 after subject selection for students heading into Years 9 and 11 the following year. Year 8 boys have the choice of 22 different subjects, although English, Mathematics, Science, History and Physical Education are mandatory. Students are asked to select an additional three subjects, plus two reserves, making up their eight subjects for Years 9 and 10. Every boy’s subject selection is monitored by his Head of House and the respective Head of Department to gauge the suitability of their choices. Once this vetting process has concluded, we construct the timetable itself. Initially, we use their requests to arrive at “lines” so that we can timetable the School.

An example of one of these lines could include: Business Studies, Design, Digital Technologies, Drama, Geography and Workshop Practices. A student who has selected Business Studies will be allocated to that class in that line of possible classes. In the past several years, we have been able to accommodate over 98% of “first” requests for Year 9 students without the need to offer their reserve subject. Indeed, some years we have had a 100% success rate; an extraordinary achievement considering there are 50 unique subject combinations in our current Year 9 cohort of 147 students, with only 22 of them taking the most common course of study. The situation is even more complex when boys are entering Year 11. The Year 10 students are offered 36 different subjects. They must select either General English or Essential English, and either Essential Mathematics, General Mathematics or Mathematical Methods but their remaining four subjects can be from a range of choices offered here at School, or at TAFE catering for their own abilities, interests, and future pathways. The number of combinations increases dramatically at this point. Of our current 151 Year 12 students, there are 115 students undertaking a unique course of study, such as TAFE or an apprenticeship, while the most common course of study has a maximum of only six students!

After we factor in additional subjects such as their pastoral care group, there are no two students who would be in the same classroom through the full two-week cycle of 60 periods per cycle. The downside is that infrequently we must ask a student to take one of his reserve subjects to be able to timetable the School. Normally this impacts fewer than ten students; however, like Year 9s, we also have a 100% success rate in some years! The point is, that we treat every year differently, starting from scratch for our Years 8 and 10 cohorts.

Once we have established the subjects that the students are allocated, and the class that they are allocated to, then the real work commences... allocating over 1000 classes for six year levels into six periods per day over the two-week cycle (Week A and Week B). For each period we need to balance each individual boy’s subject, the teacher of his class, and the room that this class may be allocated. Having a finite number of rooms and teaching staff can also be challenging as there are some periods where our general classroom usage and teacher availability is over 95%. For some subjects, such as the English or History classes, this is quite easy to accommodate as rooms do not need to be specialised.

However, for some subjects that require specialist facilities, such as the Industrial Design and Technology subjects, this can be quite challenging. An added challenge is that we arrange access for outside providers to assist with the delivery of some of the course work, such as our Certificate III in Agriculture and our Diploma of Business.

Across the School, we need to allocate 150 different subjects, across 50 periods in the two-week cycle, utilising almost 80 teachers, adding up to over 1000 classes while incorporating 39 meetings involving a total of 126 teachers. It is like a gigantic, three-dimensional, or indeed four-dimensional, jig-saw puzzle that needs to be solved to allow us to deliver the wide range of courses to the boys of Toowoomba Grammar School.

By Dr Ian Waite, Data Analyst

This is the result and what the “Master Timetable” looks like. Each coloured square can be either a single class, such as 7F English (the grey “A” for Monday Week A, period 1) or a line of many classes, such as Year 12 “W” that contains 12 different Year 12 classes for that period (e.g. Monday Week A, period 1)