Constraint recipe
If a part-time teacher does not work on Wednesdays, Wednesday is unavailable for every lesson that needs them. The harder question is whether their assigned periods fit into the remaining days without breaking team teaching, room rules, or pro-rated hour limits. Too many part-time staff off on the same day can block whole subjects.
Key takeaways
- Non-working days are unavailable for every lesson needing that teacher.
- Legal weekly hours can still be impossible to place in few days.
- Team-taught lessons need a day that works for every teacher.
- Clustered part-time days can remove capacity from one weekday.
Fixed days shrink placement options
A 0.6 teacher working Monday, Tuesday, and Thursday has no valid slots on Wednesday or Friday. Every class needing that teacher competes for time on only three days.
The issue is not only counting periods. Labs, workshops, team teaching, and shared rooms may force those periods into even fewer windows.
What to verify before moving lessons
Compare assigned periods with pro-rated caps where your local rules require them. Then check whether shared lessons have a common working day for every teacher involved.
Start with part-time teacher workload if hour limits are part of your collective agreement.
What to do next
- Record each part-time teacher's working and non-working days in the master data.
- Mark non-working days as unavailable, not as preferences.
- Sum assigned periods and compare with pro-rated caps if they apply.
- For team-taught and shared classes, list days where every required teacher works.
- Flag weekdays where many part-time teachers are all unavailable.
- Move staffing or curriculum load before treating a real non-working day as flexible.
Common mistakes
- Checking weekly totals but not whether periods fit on working days only
- Giving linked teachers different fixed days without testing shared lessons
- Taking away a teacher's day off when the real issue is too many assigned lessons
Quick answers
Can fixed part-time days make a timetable impossible?
Yes. If required lessons cannot fit on the teacher's working days, no generator can place them legally.
What is the best first fix?
Recheck assignments and shared lessons. Move load or change staffing before weakening a true non-working day.