Rostering (rostering)

Employee Shift Scheduling (Rostering) problem domain. Supports industry-standard constraints and INRC-II competition features.

Previewproblem type Rosteringmanifest 2.0

Objectives#

What the solver optimizes. Enabled objectives are weighed together.

Objective	What it means	Direction	On by default	Weight
Maximize Coverage `maximize_coverage`	Staff as many required shift slots as possible. Executable as the count of assignments; the per-shift REQUIREMENT is enforced separately as a hard constraint, so this objective ranks how much of the demand a legal roster actually serves.	maximize	Yes	1.0
Minimize Cost `minimize_cost`	Minimize total labor cost including overtime	minimize	Yes	1.0
Protect Employee Hard Constraints `minimize_employee_hard_violations`	Treat employee blackouts, location eligibility, and skill eligibility as higher-priority hard constraints than employer coverage relaxation		Yes	1000.0
Maximize Employee Preference Match `maximize_employee_preference_match`	Prefer shifts, locations, and work patterns that employees have marked as preferred	minimize	Yes	1.0
Balance Target Hours `balance_target_hours`	Steer assignments toward employee target hours while respecting min/max hour contracts	minimize	Yes	1.0

Problem inputs#

The setup values you send with a problem. The console renders them as form fields.

Problem Size#

Input	Name	Type	Required	Default	Description
`n_employees`	Number of Employees	number	Yes	10	Workers available for shift assignments
`n_shifts`	Number of Shifts	number	Yes	21	Total shifts to be covered in the planning period
`planning_horizon_days`	Planning Horizon	number	No	7	Number of days in the planning period

Shift Configuration#

Input	Name	Type	Required	Default	Description
`shifts_per_day`	Shifts per Day	number	No	3	Number of shifts in each day
`shift_duration_hours`	Shift Duration	number	No	8	Default length of each shift
`shift_type`	Shift Pattern	select	No	standard_three	Type of shift configuration

Employee Constraints#

Input	Name	Type	Required	Default	Description
`max_hours_per_week`	Max Hours per Week	number	No	40	Maximum working hours per employee per week
`min_rest_between_shifts`	Minimum Rest Between Shifts	number	No	11	Required rest period between consecutive shifts
`fairness_weight`	Fairness Weight	number	No	1.0	Weight applied to workload balance soft constraints
`preference_weight`	Preference Weight	number	No	1.0	Weight applied to employee shift/location preference soft constraints

Constraints#

A hard constraint must hold or the problem is infeasible; a soft one adds a penalty when broken.

Constraint	What it requires	Kind	On by default
Minimum Coverage `min_coverage`	Every shift staffed to ITS OWN declared requirement. This read a scalar UI default of 3 employees per shift applied uniformly, with `per_shift` defaulting to FALSE and `fallback_to_default: true` on the RequiredStaff data source - a declared fail-open on a HARD rule. On INRC-II, where per-shift demand is 0, 1 or 2, that reported a shortfall of 973 against a roster the independent certificate scored as fully covered. The limit belongs to the shift, not to the manifest.	hard	Yes
Optimal Coverage `optimal_coverage`	Reach the OPTIMAL staffing target, not merely the hard minimum. SOFT, as INRC-II scores it: falling short of optimal is a penalty, falling short of minimum is a violation.	soft	Yes
Maximum Coverage `max_employees_per_shift`	Maximum employees that can be assigned to a single shift	soft	No
Maximum Hours `max_hours_per_employee`	Maximum working hours per employee (weekly/period)	hard	Yes
Minimum Hours `min_hours_per_employee`	Minimum hours each employee should work (fairness)	soft	No
Minimum Rest Period `min_rest_between_shifts`	Minimum rest hours required between consecutive shifts	hard	Yes
Rolling 7-Day Hours Limit `rolling_7_day_hours`	Maximum hours in any 7-day rolling window (EU WTD compliance)	hard	No
Overtime Threshold `overtime_threshold`	Hours after which overtime rates apply	soft	Yes
Employee Availability `employee_availability`	Respect employee availability calendars	eligibility	Yes
Skills/Qualifications Matching `skill_matching`	Match employee skills to shift requirements	hard	No
Consecutive Working Days `consecutive_working_days`	Limits on consecutive working days without a day off. Enforced in the feasibility certificate from the problem field `max_consecutive_work_days`; weekly-repeating plans (metadata.scheduling_policy.weekly_repeating) evaluate runs across the week boundary.	hard	Yes
Fortnight Hours Cap (No Day Off) `fortnight_hours_without_day_off`	Hard cap on total hours across two weeks for an employee with no day off in the repeating weekly pattern. Enforced in the feasibility certificate from metadata.scheduling_policy.max_fortnight_hours_without_day_off (0/absent disables).	hard	Yes
Consecutive Days Off `consecutive_days_off`	Limits on consecutive days off	soft	Yes
Complete Weekends `complete_weekends`	An employee who works any day of a weekend works both. Scored by how many days are missing, so one day short of a weekend ranks better than a single day of a longer set. Previously disabled, and keyed off a modulo pattern over shift INDEXES — which assumes a shift ordering the data never promised. The weekend a shift belongs to is now read from the shift.	soft	Yes
Maximum Weekends Worked `max_weekends_worked`	Distinct weekends worked, against each employee's OWN contract. Counting distinct weekends rather than weekend shifts is the point: two shifts in one weekend is one weekend, and counting memberships would fail an employee who simply worked a single weekend twice. Previously disabled and declared as a bare `<=` against a single shared value of 2, which is wrong in one direction or the other for every roster it is applied to.	soft	Yes
Shift Type Succession `shift_succession`	Shift types that may not follow one another on consecutive days. INRC-II declares these HARD. This rule was DECLARED all along and disabled, naming a contract `forbidden_sequence` that did not exist — disabled rules escape the registration gate, so it sat inert while the manifest advertised the capability. Five of INRC-II's six bans are also incidentally caught by the 11-hour rest rule, which is what let the gap hide: Day then Early leaves 14 hours of rest, is legal by every other rule here, and is forbidden. The greedy roster on n030w4 contained 44 of them, scored by nothing.	hard	Yes
Workload Balance `workload_balance`	Balance working hours across employees	soft	Yes
Shift Type Balance `shift_type_balance`	Balance shift types (day/night) across employees	soft	No
Employee Shift Preferences `employee_preferences`	Consider employee preferences when assigning shifts	soft	No
Employee Pairing `employee_pairing`	Require or forbid specific employees from working together	hard	No
Minimum total assignments `min_total_assignments`	Each employee's contracted floor on shifts worked over the horizon. SOFT in INRC-II - loading it as hard is what made all three competition instances read infeasible.	soft	Yes
Maximum total assignments `max_total_assignments`	The matching ceiling. Soft, for the same reason as the floor.	soft	Yes

Feasibility checks#

Checked before a solve, so an impossible problem is refused with the reason.

Check	What it tests	On failure
Demand exists	Verify the planning window has required shift coverage.	fail
Employee capacity	Total employee max-hour capacity must cover total demanded shift hours.	fail
Weekly capacity	For each week in the planning window, weekly-capped employee capacity must cover that week's demanded hours.	fail
Minimum-hour pressure	Employee minimum hours are pressure unless minimum-hours is explicitly configured as hard.	warning
Skill capacity	For each required skill, skill-capable employee max-hour capacity must cover skill demand.	fail
Location capacity	For each location, location-eligible employee max-hour capacity must cover location demand.	fail
Location skill capacity	For each location and required skill, eligible skilled capacity must cover location-skill demand.	fail

Presets#

Named starting sets of constraints.

Preset	Use it for	Constraints
Basic Scheduling `basic`	Essential constraints for simple rostering	`min_coverage`, `max_hours_per_employee`, `employee_availability`
Healthcare (24/7) `healthcare`	Constraints for healthcare shift scheduling	`min_coverage`, `max_hours_per_employee`, `min_rest_between_shifts`, `skill_matching`, `consecutive_working_days`, `complete_weekends`, `workload_balance`
EU Working Time Directive `eu_compliant`	Full EU WTD compliance	`min_coverage`, `max_hours_per_employee`, `min_rest_between_shifts`, `rolling_7_day_hours`, `consecutive_working_days`, `workload_balance`