Employee Utilization

The Employee Utilization constraint allows you to control how much work employees receive, either measured in FTE hours or in number of shifts. You can set minimum targets, ideal targets, and maximum limits for any combination of employees, shifts, and time periods.

Constraint schema

object

Used to set targets and limits for the amount of hours or shifts worked by employees within given periods.

Show properties

string

required

Unique identifier for the constraint.

array of string

Labels for the constraint. Labels can be used to group constraints together. For example, if multiple constraints are related to the same shift type, they can all be labeled with the same label.

The importance of the constraint. The higher the importance, the more the solver will take the constraint into account.

object

Filters to determine the scope of the constraint. Used to decide which employees and which shifts the constraint should be applied to. Filters use logical OR filtering - an employee or shift is included as long as it is targeted by any of the filters.

Show filters – properties

object

Used to filter which employees the constraint should be applied to. If not specified, the constraint applies to all employees.

Show employees – properties

array of string

List of employee ids that the constraint should be applied to.

array of string

List of employee labels that the constraint should be applied to.

object

Show matchTypes – properties

string (enum: NONE | ANY | ALL)

Used to indicate how to apply the id filters. For example, if set to NONE, entities with the specified ids will be excluded. Default: “ANY”.

string (enum: NONE | ANY | ALL)

Used to indicate how to apply the label filters. For example, if set to ANY, entities that have any of the specified labels will be included. Default: “ANY”.

object

Used to filter which shifts the constraint should be applied to. If not specified, the constraint applies to all shifts.

Show shifts – properties

array of string

List of shift ids that the constraint should be applied to.

array of string

List of shift labels that the constraint should be applied to.

object

Show matchTypes – properties

string (enum: NONE | ANY | ALL)

Used to indicate how to apply the id filters. For example, if set to NONE, entities with the specified ids will be excluded. Default: “ANY”.

string (enum: NONE | ANY | ALL)

Used to indicate how to apply the label filters. For example, if set to ANY, entities that have any of the specified labels will be included. Default: “ANY”.

object

Defines filtering for specific work that the constraint should be applied to. For example, it can be used to apply the constraint only to work carried out in specific roles.

Show work – properties

object

Used to apply the constraint only to work carried out in specific roles.

Show roles – properties

array of string

List of relevant role ids.

object

Used to apply the constraint only to work carried out with specific workload categories.

Show workloads – properties

array of string

If specified, the shift must have at least one of the workload categories specified in this list.

object

Specifies the target utilization for the constraint. Targets can be specified in number of FTE hours, or in number of shifts worked during the period.

Show targets – properties

number

The minimum number of hours that should be worked by employees on shifts that match the constraint in each period. This is treated as a target - it is not guaranteed that the number of hours worked will be greater than this value.

number

The ideal number of hours that should be worked by employees on shifts that match the constraint in each period. This is treated as a target - it is not guaranteed that the number of hours worked will be exactly this value.

number

The maximum number of hours that should be worked by employees on shifts that match the constraint in each period. This is treated as a hard limit - the number of hours worked will never exceed this value.

integer

The minimum number of shifts that match the constraint that an employee should work in each period. This is treated as a target - it is not guaranteed that the number of shifts worked will be greater than this value.

integer

The ideal number of shifts that match the constraint that an employee should work in each period. This is treated as a target - it is not guaranteed that the number of shifts worked will be exactly this value.

integer

The maximum number of shifts that match the constraint that an employee should work in each period. This is treated as a hard limit - the number of shifts worked will never exceed this value.

object

Settings to determine if and how bonus time rules affect the constraint.

Show bonusTime – properties

boolean

Whether or not bonus hours should be included in the calculation of an employee’s total hours worked for the constraint. Default: true.

number

If a threshold is provided, bonus hours will only be included in the calculation of an employee’s total hours worked if the average bonus hours per period exceed this threshold.

number

If a cap is provided, the average number of bonus hours per period will be capped at this value. The employee can be eligible for more bonus hours, but they will not be counted beyond this cap.

object

Specifies overlap thresholds that a shift must meet with the constraint’s periods in order for it to be counted as relevant for the constraint.

Show overlapRules – properties

integer

The minimum number of hours that a shift must overlap with the constraint in order to be counted as relevant for this constraint.

integer

The minimum percentage of the shift that must overlap with the constraint in order to be counted as relevant for this constraint.

object

List of periods in the schedule. Periods can either be defined explicitly using custom definitions, or through a recurrent definition. A recurrent definition can be used to easily generate a list of similar periods (such as weeks, months, etc.).

Show periods – properties

object

List of days in the schedule. Each day will become one period. By default, each period will last the entire day. If a startTime and/or endTime are specified, these will apply to each period.

Show days – properties

array of date (date)

List of dates in the schedule. Only allowed in CALENDAR payloads.

array of dayIndex

List of day indices in the schedule. Only allowed in RECURRING payloads.

array of dayOfWeek

List of days of the week. Will apply to all days in the schedule that match any of the specified weekdays.

string (time)

TIME ISO 8601 format hh:mm. Equivalent to the 24h format of a single day. Use 00:00 to represent midnight.

string (time)

TIME ISO 8601 format hh:mm. Equivalent to the 24h format of a single day. Use 00:00 to represent midnight.

array of object

List of custom period definitions. Each custom period definition defines one period in the schedule.

Show customDefinitions – item structure

object

Describes one day in the schedule. Can be defined as a date (in CALENDAR payloads) or as a day index (in RECURRING payloads).

Show startDay – properties

string (date)

Date is specified in ISO8601 format YYYY-MM-DD. Can only be used when schedule type is CALENDAR.

integer

Day index relative to the first day of the period (starts at 0). Can only be used when schedule type is RECURRING.

object

Describes one day in the schedule. Can be defined as a date (in CALENDAR payloads) or as a day index (in RECURRING payloads).

Show endDay – properties

string (date)

Date is specified in ISO8601 format YYYY-MM-DD. Can only be used when schedule type is CALENDAR.

integer

Day index relative to the first day of the period (starts at 0). Can only be used when schedule type is RECURRING.

string (time)

TIME ISO 8601 format hh:mm. Equivalent to the 24h format of a single day. Use 00:00 to represent midnight.

string (time)

TIME ISO 8601 format hh:mm. Equivalent to the 24h format of a single day. Use 00:00 to represent midnight.

boolean

If true, the startTime and endTime will be applied to each individual day in the period. If false, the startTime will apply to the first day and the endTime will apply to the last day. Default: false.

object

A recurrent definition to easily create a set of similar periods.

Show recurrentDefinition – properties

integer

required

The number of days in each period.

integer

The number of days between the start of each period. If not specified, this defaults to the value of daysPerPeriod, creating non-overlapping consecutive periods. Setting daysBetweenStarts to 1 will create a sliding window of periods.

object

Describes one day in the schedule. Can be defined as a date (in CALENDAR payloads) or as a day index (in RECURRING payloads).

Show startDay – properties

string (date)

Date is specified in ISO8601 format YYYY-MM-DD. Can only be used when schedule type is CALENDAR.

integer

Day index relative to the first day of the period (starts at 0). Can only be used when schedule type is RECURRING.

object

Describes one day in the schedule. Can be defined as a date (in CALENDAR payloads) or as a day index (in RECURRING payloads).

Show endDay – properties

string (date)

Date is specified in ISO8601 format YYYY-MM-DD. Can only be used when schedule type is CALENDAR.

integer

Day index relative to the first day of the period (starts at 0). Can only be used when schedule type is RECURRING.

string (time)

TIME ISO 8601 format hh:mm. Equivalent to the 24h format of a single day. Use 00:00 to represent midnight.

string (time)

TIME ISO 8601 format hh:mm. Equivalent to the 24h format of a single day. Use 00:00 to represent midnight.

boolean

array of string

Provide labels to re-use periods that were defined in the configuration.

How targets work

The constraint supports three types of targets for both hours and shifts:

Minimum targets (minHours, minShifts): The solver will try to ensure employees work at least this amount. These are treated as soft targets and may not always be met if other constraints conflict.
Ideal targets (idealHours, idealShifts): The solver will try to assign exactly this amount. This is useful when you want employees to work a specific number of hours or shifts.
Maximum limits (maxHours, maxShifts): These are hard limits that will never be exceeded. The solver will strictly enforce these bounds.

You don’t need to specify all targets - only include the ones relevant to your use case. For example, you can set only maxHours to cap the total hours, or only idealShifts to target a specific number of shifts.

Global utilization targets

Set utilization targets for the entire planning horizon. This is useful for ensuring employees receive a fair distribution of work across the entire schedule.

The constraint below sets targets for employee-1 across the entire planning horizon:

The employee should work at least 80 hours (soft target)
The employee should ideally work exactly 120 hours
The employee may work no more than 160 hours (hard limit)

{
  "id": "euc-total-hours",
  "targets": {
    "minHours": 80,
    "idealHours": 120,
    "maxHours": 160
  },
  "filters": {
    "employees": {
      "ids": ["employee-1"]
    }
  }
}

Period-based utilization targets

All targets are applied to each period separately. By defining periods, you can create constraints that apply to specific time windows, such as weekly or monthly targets.

The constraint below sets a weekly target for all employees. Each employee should ideally work 40 hours per week, with a minimum of 32 hours and a maximum of 48 hours.

{
  "id": "euc-weekly-hours",
  "targets": {
    "minHours": 32,
    "idealHours": 40,
    "maxHours": 48
  },
  "periods": {
    "recurrentDefinition": {
      "daysPerPeriod": 7
    }
  }
}

Shift-based limits

You can limit the number of shifts of a specific type that employees can work. This is particularly useful for controlling undesirable shifts like night shifts or weekend work.

The constraint below sets a strict upper bound of 2 night shifts per week for all employees. After an employee has worked 2 night shifts in a week, they cannot be assigned any more night shifts that week.

{
  "id": "euc-night-shifts-per-week",
  "targets": {
    "maxShifts": 2
  },
  "filters": {
    "shifts": {
      "labels": ["night"]
    }
  },
  "periods": {
    "recurrentDefinition": {
      "daysPerPeriod": 7
    }
  }
}

Minimum shift requirements

You can also set minimum shift requirements to ensure employees receive a certain amount of work.

The constraint below ensures that each employee works at least 3 shifts per week, with an ideal target of 5 shifts. This helps prevent employees from being underutilized.

{
  "id": "euc-min-shifts-per-week",
  "targets": {
    "minShifts": 3,
    "idealShifts": 5
  },
  "periods": {
    "recurrentDefinition": {
      "daysPerPeriod": 7
    }
  }
}

Combining hours and shifts targets

You can combine both hours and shifts targets in a single constraint to create more nuanced requirements.

The constraint below ensures employees work between 3-5 shifts per week, with each shift ideally being around 8 hours. This creates a balanced schedule where employees get enough shifts but not too many.

{
  "id": "euc-balanced-weekly",
  "targets": {
    "minShifts": 3,
    "idealShifts": 4,
    "maxShifts": 5,
    "minHours": 24,
    "idealHours": 32,
    "maxHours": 40
  },
  "periods": {
    "recurrentDefinition": {
      "daysPerPeriod": 7
    }
  }
}

Setting limits on specific roles

You can set limits on the number of hours or shifts that employees can be assigned to specific roles.

The constraint below limits employees to a maximum of 50 hours per week worked with role role-1, while aiming for them to work at least 35 hours.

{
  "id": "euc-role-1-max-50-hours",
  "targets": {
    "minHours": 35,
    "idealHours": 40,
    "maxHours": 50
  },
  "filters": {
    "work": {
      "roleIds": ["role-1"]
    }
  },
  "periods": {
    "recurrentDefinition": {
      "daysPerPeriod": 7
    }
  }
}

The constraint below ensures that employees work at least 2 weekend shifts per month, helping to distribute weekend work fairly.

{
  "id": "euc-weekend-shifts",
  "targets": {
    "minShifts": 2,
    "idealShifts": 3
  },
  "filters": {
    "shifts": {
      "labels": ["weekend"]
    }
  },
  "periods": {
    "recurrentDefinition": {
      "daysPerPeriod": 30
    }
  }
}

Getting started

Concepts

Entities

Other

Constraint schema

How targets work

Global utilization targets

Period-based utilization targets

Shift-based limits

Minimum shift requirements

Combining hours and shifts targets

Setting limits on specific roles