The Art of Timetabling: Principles and priorities

NovaT6 - one of many packages,  familiar to timetable wizards.
NovaT6 – one of many packages, familiar to timetable wizards.

This is the crunch time for the legion of timetablers across the country – and for the teachers who wait to see what they come up with.  As a former timetabler myself, I’d like to dedicate this post to my partners in crime, especially Matt who is working on the Highbury Grove timetable right now.  We’ve come a long way from the days of pins and peg-boards but the basic principles are exactly the same as ever – we’re trying to match teachers to classes and teaching spaces in the most effective way possible so that students and teachers have a working week that gives us the best chance of delivering the curriculum that we’ve planned.  It’s not rocket science but it’s a major challenge.  The software helps in lots of amazing ways to visualise the multi-dimensional puzzle but it’s not as if you can press a button and get a beautiful solution – far from it.  Even with great software, it’s a sophisticated process, blending technical puzzle-solving with an acute awareness of the human issues surrounding staff deployment and the implications for students’ experience of school.  As we were discussing today, the mathematics of it is the easy part; it’s the human element that presents the challenge: not everyone can get what they want or sees the big picture when fighting their corner.

The reality is that you can’t make everything fit without making compromises. Good compromises need to be based on some principles and those need to be informed by the school ethos – the priorities for learning, the well-being of staff and students, professional development and so on.  You can pretty much deliver anything with a timetable if it matters enough – but you can’t deliver everything.  The challenge is to decide which things to sacrifice and which things to protect and sometimes, two choices are mutually exclusive – it’s one or the other because you can’t have both.

I actually love timetabling – it’s hugely rewarding to solve the giant puzzle and to present it to everyone.  At BIS in Jakarta, I wrote the timetable for our 3-18 through-school for over 100 staff where teachers of MFL, Performing Arts and PE taught throughout the school.  I remember the joys of trying to slot in Pre-School Swimming, which had very special requirements, alongside IB and KS4 option blocks where the secondary school had a two-week timetable but the primary division didn’t.  Fun and games.  Another time I made a mistake blocking out the non-working days for some key part-time staff and had to start again just after I thought I’d finished. Hours of work wasted – but I secretly relished the chance to do it again.  The easiest timetable I ever had to write was for a new school with just Year 7.  It took about an hour.

Screen Shot 2015-05-19 at 23.36.19
Kenyan timetable. It’s the same the whole world over.

These are some of the considerations:

Class allocations:  

Beyond the simple maths of making sure you’ve got enough teachers to teach all the classes, you’ve got to allocate them in a way that makes sense and seems fair.  People can get very precious about this because it determines their working world for a whole year. We’ve been taking time to make sure we’re giving people a spread of classes across key stages and sets.  It’s always annoying when people think they ‘don’t do the little ones’ or when a Head of Department gives himself all the top sets. (I know examples of these things from different contexts.). No-one gets better at teaching A level or lower attaining Year 9 groups if they never actually do it – and no one class should be seen as less important than another.   The difficulty with this process is the communication – it’s hard to share all the details with everyone until it’s all done. Ideally people should know roughly what to expect before the timetable is done and can’t be changed.  Of course, a timetabler’s joy is a teacher who is happy to teach whatever is needed – no problem, no fuss.

One class, one teacher or split classes

Split classes cause problems because of the need for continual communication and/or the need to split the curriculum into sections.  For students, the more teachers they have, the more fragmented their school week becomes and there is a limit.  In my daughter’s first year of secondary school, they had gone setting crazy – as if that was the only thing that mattered.  The only way to achieve the blocking needed for the setting had been to split lots of classes between two teachers;  she had 17 different teachers per week:  two teachers for most core subjects and, in one case, three teachers.  After a re-setting process mid-year, she ended up with over 25 teachers in one school year. That’s timetabling gone wrong – where one set of theoretical priorities haven’t been mapped through to the experience of the students.

For me, splitting classes should be avoided wherever possible – but, of course, it’s inevitable and has to be managed.  Sometimes its just a case of making loadings fair between two teachers; you can’t always get the quantum numbers of lessons per group to add up neatly and it can be uneven without a few splits.

Blocking and Setting

The more blocking you have, the fewer degrees of freedom you have to move things around.  Large option blocks or setting blocks in core subjects quickly get locked in.  It’s nice to have some single class, single teacher classes to slot in at the end.  Of course, there can be very good reasons for wanting blocking – the trick is to recognise the trade-offs – ie that it means not everyone can teach groups they’d like and that there’s a bigger risk of needing to split classes.  I’ve often found that you need to do the PE timetable first because you usually need every single teacher on at the same time for every year group and it quickly becomes impossible to achieve that once other things get in the way.

Part-time staff

Part-time timetables are a huge constraint – when a teacher you really need can only work on certain days. However, part-time working is a vital part of a healthy school culture.  Schools should be good family-friendly places to work and to bring up children or that allow people to step down to retirement; this is how you keep good people in the profession.  At the same time, a part-time teacher shouldn’t necessarily call the shots on the days they can work because this can have an effect on lots of other people.  It’s important to have a lexible but positive attitude.


A big bug-bear of teachers is when they have to move around a lot. This can be really difficult.  Most new schools are designed on a principle of very high occupancy rates – around 95%, when teachers have a maximum 80% loading. There are always more teachers than rooms so moving around is inevitable. The question is – who moves and how often?  Good rooming should give the greatest stability to the people who need it most.  It also helps for rooms to be linked to departments to a degree; it’s amazing how tatty rooms become when no one feels it is theirs. On the other hand – gosh, do people become territorial about rooms!  I’ve often tried to persuade people that every room belongs to everyone – it’s a hard sell!

Lesson flow

Sometimes it is tempting to be happy just to have found a solution to the timetable. It works. But then you look more closely.  John has three consecutive full days and then only one lesson on Thursday – that kind of thing.  Or, the software has allocated all the History lessons in Week A and none in Week B.   Or students have Art, PE, Music and DT all on one day.  These things aren’t terminal they are the imperfections that don’t sit well.  There are good timetables and bad timetables.  The greatest art in timetabling is solving the puzzle in a way that gives a good flow to lessons for everyone.  The acid test is looking down the staff list and checking whether you’re worried about what anyone will have to say.  Usually you need to have a word with a few people to explain that you did your best but you know they’ve got something that isn’t ideal.  It’s also usually the case that the problem needs to be really very big for you to face re-doing the thing all over again.

So – to timetablers everywhere.  Good Luck!! Push that button.


  1. Working on ours now – having joint IB and A level groups in languages and art with a clutch of partnership staff from local secondaries and a family-friendly part time policy is tough, but I don’t envy you the pre-school swimming scheduling!!

    Liked by 1 person

  2. Is there a disproportionate number of science teachers who become timetablers? In the 11 years I have taught all but two years it has been a scientist doing the timetable and those years it was DT & computer science teachers, and in those years the physicist head of science was called upon to sort problems when they reached a dead end. It is certainly something I would relish the challenge of one day.


  3. I think of it like playing tetris. Once the science timetable is done ( over 320 hours) I hand the dept timetable back to the Deputy Head and cross my fingers. He said next year I can have a bigger role in the whole school one.. I relish the challenge of tetris on a bigger board!


  4. Tom, you might be interested in the project I’m working on to develop methods for generating more creative and flexible timetables.

    As a founder of Wapping High School I observed how difficult it is to fully personalise the education experience for each student using the existing methods and software tools. I’m working on a project with schools across the country to develop new tools and methods for more creative curriculum design that will sit alongside the standard timetabling optimisation tools. Would you and your timetabler Matt be interested in contributing to the research?

    I’d love to hear from any other schools that are interested in getting involved.


  5. What about teachers teaching outside their department? Would you rather have a music teacher teaching science or a science teacher teaching music? Do you have non-specialists teaching mfl? If so, how do you allocate them? I imagine timetabling is a pretty thankless task!


    • Allocating staff is a question of knowing their strengths and interests – and their experience, qualifications etc. Some teachers can teach more than one subject; others can’t. I’m a believer in maximising specialist teaching; weak subject knowledge is often a problem in delivering the outcomes students deserve. On the other hand, some teachers can be very versatile.


  6. Useful guidance here all of which matches what my Principal has offered me in terms of advice. I’m currently putting the final touches to our TT and the biggest thing I have learnt is the importance of strong interpersonal skills needed when having the conversations with staff whose TT is “less than ideal”. Those conversations can be difficult and it could be easy to get bullied by vocal HoDs or longer serving members of staff. Don’t be afraid to stand your ground!

    Liked by 2 people

  7. About 10 years ago I caught my headteacher… (dun dun DUN) planning next years timetables. Such a normal thing you might say but as a student I saw this entirely differently. First: it looked like allot of fun! Lots of subjects, rooms, teacher availability etc to juggle. “Man!” I thought, “I’d have loved to have done that planning! In fact, I’m sure I could design a computer system for her that would beat all her little pieces of paper” (happy to see from this post that someone’s gone and done that!) and then I thought more closely… she was literally planning where me, my friends, the whole school, including the teachers would be for the next whole year. Yes, with care and attention. But, that’s a whole year regardless of anything that can happen in any of our lives or in the world and, because subjects are necessarily part of this, she’s simultaneously deciding what we would be doing the whole time. This made me feel a little sick and the feeling hasn’t gone away. I’m sure by saying this here I’ll be heckled around arguments about practicality e.t.c, that’s fine. I get it. As long as we have school enclosed systems this is the only way to do it so, that being said, for all of you who love timetabling check out logic puzzles; you’ll love them if you’re not already hooked! Here is a decent looking website as the magazines don’t seem to be popular in the UK any more: Enjoy!


  8. Just one observation from an English teacher who got to headship without ever having done a whole-school timetable….

    I realised as a deputy about to start applying for headships that it was the one BIG thing in the school I hadn’t done. I’d organised cover and planned internal exam timetables so I’d used some of the skills in miniature (both the logic of it and also the people skills of negotiation and persuasion!) but I hadn’t had responsibility for the whole-school timetable and realised that I needed to learn more about the principles and processes behind timetabling if I were to be a well-informed head.

    So I went on an external day’s timetabling course.

    It was one of the most humbling experiences of my career. I could understand the principles and do what the course leader asked us to do BUT I just wasn’t as quick as those (mainly maths and science specialists) around me and that really knocked my confidence. It got to the point that when we were asked to do something, and the young Chemist next to me was saying, ‘Done that – what next?’ before I’d got my head round it, I had the experience of something like a red mist descending when I looked at what was in front of me and couldn’t focus. Suddenly I realised what it was like for the pupils in the classes I taught who found my subject more taxing than some of the others. How intimidating is it when some pupils’ hands are shooting up while you’re still trying to work it out?

    When I went home I sat at the kitchen table and worked through all the exercises he’d given us just to prove to myself I could do everything asked of us – but in my own time.

    Then in my lessons I went for a ‘no hands up’ approach – gave everyone enough thinking time and supported those who found it more challenging to get there without being put off by the quickest.

    We learn so much more by being in the struggle zone – but it’s important not to tip over into the panic zone!

    Thanks for the post, Tom!

    Liked by 2 people

  9. You speak of 95% occupancy. Is there a ballpark standard percentage to aim for in timetabling say a typical international school curriculum? I hear 80% mentioned but i usually need to try for higher.


  10. I’m an English specialist Deputy Head and timetabling bothered me so much I put off applying for Curriculum and Standards jobs for a couple of years. The solution for me was to know our staff really well and our curriculum inside out, and then pay someone external to make everything fit. Usually done very quickly and effectively, more so than if I had to dust my manual off once a year. It’s very cost effective considering how much time I’m sure I’d spend trying to relearn everything once a year!

    Liked by 1 person

    • I’m the principal of an international school in SE Asia, and I’ve just started using Penalara Software.

      Works beautifully! I used to spend nights and nights making the timetables at the beginning of every school year… now I just have to put the data in, and it works! It also syncs with school management programs, and you can print off the timetables for your students, teachers, classrooms….

      I’d seriously give it a try if I were you!


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