Constraint recipe
A lab block is a double-period practical session in a specialist room. Both periods need the same teacher, class, lab, and equipment. Moving only the first period while leaving the second elsewhere breaks the block. Place scarce lab blocks early and check capacity across the full session.
Key takeaways
- A lab block needs two adjacent periods in the same lab.
- Check teacher, class, room, and equipment for both periods.
- Capacity can make a free lab unusable for the group size.
- Place scarce lab blocks before flexible classroom lessons.
Why lab blocks are tight
Labs are scarce and often shared across year groups. A block reserves the room across two periods, so one clash can affect several flexible lessons waiting for that lab.
Treat lab blocks as part of data preparation, not as a last-minute edit after generation.
What to check before moving a lab
Open the whole block: teacher availability, class availability, lab availability, equipment, and transition time between periods. Splitting the block only works when the curriculum allows two separate singles.
For workshops and vocational labs, see workshop and lab scheduling.
What to do next
- List lab sessions that require adjacent periods.
- Map each session to eligible labs and required equipment.
- Check availability for every period in the block.
- Compare group size with lab capacity.
- Place the most constrained lab blocks before flexible lessons.
- Split only when the curriculum allows separate single periods.
Common mistakes
- Checking room type but not whether the lab fits the group size
- Scheduling two lab blocks that share the same limited equipment
- Splitting a block that exists because the activity needs sustained time
Quick answers
Are lab blocks mandatory rules?
They are mandatory when the activity cannot run without the lab or adjacent periods. Otherwise they can be a preference.
Why do lab blocks cause room clashes?
They hold a scarce room across two periods, so one wrong placement collides with several flexible lessons.