During the summer period, our support team often gets asked this question: ‘’My timetable is almost done, but I can’t seem to get it past 99%, how can I get it to 100%?’’

While this situation only arises for some schools, it’s important to understand the possible reasons for getting ‘stuck’ before being fully scheduled. Any change to teachers, the curriculum or to the grid, no matter how small, can mean that sometimes the solver will find it harder to schedule fully than it did the previous year.

Going over the basics is a good place to start. Ensuring you have a good grasp on the main functions in timetable construction means you will be able to identify simple errors more easily. The extensive timetable guides we have will help you with this.

Timetabling Guides

The good news is that there are steps you can take to make it more likely that you’ll reach 100%. And if you’re still left with a handful of stubborn lessons, we have a few tricks up our sleeve that can help you in this scenario too. What better time than now to get a head start!

Where Possible, move blocks to core

Take a look in screen 5, Class Data. Blocks are much harder to schedule than core classes, because we’re asking the solver to run multiple lessons at once. In most schools, it’s normal to place most of the 5th and 6th year teaching groups into blocks because students often need the option to switch their subject level mid-year. However, you could consider moving blocked teaching groups in the other years into core where possible.

Only assign rooms specific rooms where necessary

Remove any unnecessary rooms from screen 5, Class data. When rooming a timetable, the best practice is to only ever manually assign rooms to practical or specialist subjects such as PE, Home Ec., Science etc. The rest of the rooms can be automatically assigned. If you overdo it by manually placing rooms with subjects (or teachers) that don’t really need them, you’re creating a significant barrier for the solver to overcome, and this may be why the file is stuck.

Reduce Restricions

Minimise your restrictions. In screen 3, Teacher Data, is the screen filled with red cells indicating days off for teachers? Perhaps some could be removed or changed to desired rather than mandatory. In screen 7, Construction, if there are pinned lessons here, can they be removed? When you go to Actions > Restrictions, question any restrictions you have in here and remove where possible. For example, sometimes a school will restrict non-exam subjects from running first thing in the morning for 6th years, because there can sometimes be problems with students not showing up for these classes. While this is a legitimate reason to want to input this restriction, it’s worth trying to remove it to identify if it is causing a larger problem with the file. Then, if you have established that it is causing a problem, you’ll be in a better position to decide if you can remove that restriction.

When you’re going through these steps, it’s best to first try them one by one, in different combinations and then together, while cloning your main file each time. This will allow you to pinpoint which one (if any) is causing the issue.

If you end up in a situation where these approaches don’t get your file to 100%, and you are left with a small number of lessons that won’t schedule (1-10), then you can start manually trying to place the lessons onto the grid in screen 7, Construction. The support team can assist you here also, but it’s just a matter of placing the lesson onto the grid and then using screen 8, View to swap teachers or lessons where appropriate. It’s important to remember that small changes can make a big difference. For example, if you can’t schedule 10 lessons, swapping just one teacher could resolve the problem, so trying lots of small changes is definitely worthwhile.

Start Early

Because every school is different and has varied requirements, getting to 100% with a tricky timetable can sometimes take more time and effort than usual. For this reason, we would strongly recommend that you complete your file as soon as is possible for you. Getting it very close is no guarantee that the last few percent will be equally easy to complete

Finally, this change made last year is important to keep in mind: the proposed changes to the length of class periods, as outlined by the Department of Education and Skills in the Circular Letter 0015 /2017. Below is an extract from section 2.10. Timetabling:

‘’With effect from September 2017 schools must ensure that class periods of less than 40 minutes are no longer timetabled. Some schools may find the use of longer class periods of up to 60 minutes (rather than 40 minutes), more suited to the learning needs of their students and the subjects they study or a combination of class periods of 40 minutes and longer class periods of up to 60 minutes.’’

In reality, this means that some schools will have to reduce the overall amount of lessons on their weekly grid. It’s important to note that if you alter your grid, the existing curriculum will need to be modified to work around this change and this will require some planning, so anticipating these adjustments will make the transition into the next academic year run more smoothly.

Click here to view the Department’s circular letter.


Don’t forget, the support team are here to help you through the timetabling period. However if you think you could use a little extra help, our expert trainers are available to visit your school to provide timetable consultancy. Fill out this form to find out more and secure a date.