How to change a timetable mid-year without starting again

The timetable that starts the year is rarely the one that ends it. A teacher leaves at Christmas, a new group is needed in October, a room floods, or a part-time teacher changes their days. Each change is small, but timetables are tightly connected, and moving one lesson can mean moving many others.

Here's how to make mid-year changes without unpicking the whole thing.

Decide what must not move

The biggest cost of a mid-year change is disruption. Students and staff have learned their timetable, and parents may have arranged transport around it. Before you change anything, decide what's locked:

• Exam groups, especially Year 11 and Year 13
• Whole-year-group setting, which is hard to rearrange
• Lessons taught by staff who aren't affected

The more you lock, the less disruption, but the fewer options you have for fitting the change in.

Make the smallest change that works

Start with the smallest possible change, and only widen it if that fails:

1. Swap like for like. A new teacher takes over the leaving teacher's lessons exactly as they are.
2. Move only the affected lessons. Find new slots for the lessons that have to change, leaving everything else alone.
3. Re-timetable one year group or department. If the change can't fit, open up a slightly larger part of the timetable.
4. Re-timetable more widely, only as a last resort, and ideally at a natural break like the start of a term.

Check what the change affects

A change that fixes one problem can quietly create another. After every change, check:

• No new clashes for students, teachers or rooms
• Part-time staff are still only timetabled on their days
• Student gaps haven't got worse
• Specialist rooms are still used by the lessons that need them

Keep a record

Keep the original timetable and a note of every change: what changed, why and when. When questions come up later, or when you build next year's timetable, you'll know why things are the way they are.

Communicate clearly

Tell everyone affected what is changing and from when, and give them their new timetable, not just a list of changes. Update your MIS at the same time, so registers and cover match.

How Timez helps

The hardest part of a mid-year change is knowing what it will affect. Because Timez keeps each timetable's data and settings in a project, you can set up a separate project with your current data plus the change, and generate a version that meets every hard rule, while the live timetable stays untouched. Then compare the analytics, including student gaps and teacher and room utilisation, before anything is published.

If the change can't fit with the staff and rooms you have, Timez tells you rather than producing a timetable that quietly breaks a rule.

Related: how to build a school timetable and hard and soft constraints.