Hard constraints

Hard constraints are rules that every valid roster must satisfy. A roster that violates any hard constraint is rejected entirely — the engine will not return it, even if it scores well on soft preferences.

If no roster can satisfy all hard constraints simultaneously, the engine returns an infeasible result with a list of the specific dates and rules that caused the conflict.

Assignment

• One shift per person per day
• No night-to-morning transition
• Two off days per calendar week

Coverage

• Minimum shift coverage
• Maximum shift coverage
• Maximum working employees per day
• Date-range coverage overrides
• Regular shift assigned after core shifts

Leave

• Typed leave must be honored exactly
• Annual and comp-off only on requested dates
• Comp-off cannot exceed valid balance
• Leave capacity gate per day

Fairness

• Core shift balance per employee