Placement Settings

Before generating placements, you can configure settings that control how the algorithm distributes students across classrooms. These settings affect classroom size limits, boy/girl difference limits, and how larger feeder-school groups are spread across classrooms.

Click Save Placement Settings and wait for the saved confirmation. If the connection fails, your entries stay in the form; reconnect and click Save again. Unsaved settings are not used for generation.

If another tab changes the workspace, Shibutz stops the stale save. Choose Reload saved data, review the latest workspace and your form entries, then save again. Generation is unavailable while saves are pending or a save error needs attention.

Default Students per Classroom

This setting defines the maximum number of students that can be placed in a classroom unless that classroom has its own custom capacity. The algorithm will not exceed the active limit when distributing students. If you leave the field blank, classrooms without custom capacity do not use a workspace default cap.

• Check the saved value against the roster and the rooms available. A capacity limit is a ceiling, not a promise of equal classroom sizes.
• Increase a cap only within school-approved staffing and policy limits, not simply to improve a friend percentage.
• You can leave the field blank when you only want per-classroom custom capacities. A blank field does not establish that unlimited classroom size is appropriate for your school.
• Setting the cap too low may prevent the algorithm from finding a valid placement, especially when combined with required placements.
• Individual classrooms can override this workspace default. See Setting Classroom Capacity for per-classroom overrides.

Boy/Girl Difference Allowed per Classroom

This setting controls the maximum allowed difference between the number of boys and girls in each classroom. A lower number means stricter boy/girl balance enforcement.

• Example: A value of 3 means no classroom can have more than 3 more boys than girls, or vice versa.
• The lowest supported value is 1, and there is no fixed upper cap. Use the smallest gap that still reflects your school's real roster mix.
• Setting the limit too low with an uneven overall gender ratio can cause generation to fail. If this happens, try increasing the limit.

This is a hard limit, not a soft target for matching a cohort-wide percentage. Students recorded as Other count toward classroom size, but not the male/female difference. Manual entry and import both support Other; see student roster fields.

Split Larger School Cohorts Across Classrooms

This setting is on by default. It helps prevent a large group of students from the same previous school from landing in one classroom, while still trying to keep very small school cohorts together when that is practical.

• Small same-school groups may stay together when other constraints allow it. The setting does not guarantee a specific grouping.
• Larger cohorts are balanced more gently across classrooms to avoid outcomes like one class receiving most of a feeder school.
• Turn this off only when preserving school cohorts matters more than spreading them across the new class list.

How Settings Affect the Algorithm

The algorithm uses your settings as boundaries during generation:

• Default students per classroom acts as a hard cap — no classroom will have more students than its active limit. When the default is blank, only classrooms with custom capacity have a size cap.
• Boy/girl difference allowed per classroom is enforced as a constraint — the algorithm rejects arrangements that violate the limit.
• Split larger school cohorts is a balancing preference rather than a hard constraint. It gives the algorithm a stronger reason to avoid putting a large same-school group in one classroom while leaving room for required placements and other rules.
• Together with restrictions and required placements, these settings define the feasible solution space. The tighter your constraints, the fewer valid arrangements exist.

Recommended Defaults vs. Custom Tuning

Check saved settings against your school's approved limits before the first run. Then change one setting at a time:

• Start with approved limits. Run a generation and review the results. Only adjust if the output doesn't meet your needs.
• Review capacity conflicts with the person responsible for staffing. Add a classroom or change a cap only when approved; retain necessary support and separation rules.
• Relax the boy/girl limit if your student population has a significant gender imbalance — requiring strict balance with uneven numbers is often impossible.
• Keep school cohort splitting on unless your staff has a specific reason to preserve larger feeder-school groups.
• Tighten settings gradually. If you want stricter constraints, adjust one setting at a time and re-generate to see the effect.