ATS.OR.320, the article that specifies what a rostering system must control

The article, verbatim

(a) An air traffic control service provider shall develop, implement and monitor a rostering system in order to manage the risks of occupational fatigue of air traffic controllers through a safe alternation of duty and rest periods. Within the rostering system, the air traffic control service provider shall specify the following elements:

1. maximum consecutive working days with duty;
2. maximum hours per duty period;
3. maximum time providing air traffic control service without breaks;
4. the ratio of duty periods to breaks when providing air traffic control service;
5. minimum rest periods;
6. maximum consecutive duty periods encroaching the night time, if applicable, depending upon the operating hours of the air traffic control unit concerned;
7. minimum rest period after a duty period encroaching the night time;
8. minimum number of rest periods within a roster cycle.

(b) An air traffic control services provider shall consult those air traffic controllers who will be subject to the rostering system, or, as applicable, their representatives, during its development and its application, to identify and mitigate risks concerning fatigue which could be due to the rostering system itself.

Consultation under (b) is not a side note. Read the full requirement, what it does and does not oblige, atconsulting controllers on a rostering system →

• Element 1

  Maximum consecutive working days with duty

  Count consecutive duty days per controller and stop assignment once the configured maximum is reached.

  • Days on the roster in a row stay under the limitStrategichard or soft
  • A swap cannot extend a run of working days too farSwaphard

  configured Strategic rostering →

• Element 2

  Maximum hours per duty period

  Bound the length of a single duty period from sign-on to sign-off.

  • Hours worked in a day stay under the daily limitStrategichard or soft
  • A single shift stays inside its own hours limitStrategichard or soft

  configured Strategic rostering →

• Element 3

  Maximum time providing ATC service without breaks

  Track continuous time on an operational position and force a break once the configured ceiling is reached.

  • Continuous time on position has a hard ceilingTacticalhard or soft

  configured Sector planning →

• Element 4

  Ratio of duty periods to breaks

  Hold a set proportion of break time to working time across a duty period, a ratio, not one fixed break.

  No single named rule covers this one. It falls out of element 3's ceiling and a separate minimum-time-on-position floor, rather than existing as a rule in its own right. If a unit's policy needs the ratio itself enforced as one number, that is a configuration conversation to have directly, not something the catalogue answers off the shelf.

  configured Sector planning →

• Element 5

  Minimum rest periods

  Guarantee a minimum gap between the end of one duty and the start of the next, for every duty.

  • There is a minimum rest gap between two dutiesStrategichard or soft
  • Rest before going on position is checked on the dayTacticalhard or soft
  • A swap cannot cut anybody below minimum restSwaphard

  configured Shift swaps →

• Element 6

  Maximum consecutive duty periods encroaching the night time

  Count consecutive duty periods that fall inside the defined night-time window and cap the run.

  • Nights in a row stay under the unit's limitStrategichard or soft
  • Night duty within a run of days stays under a ceilingStrategichard or soft

  configured Strategic rostering →

• Element 7

  Minimum rest period after a duty period encroaching the night time

  Apply a longer minimum rest specifically after a duty that touched night time, distinct from the general inter-duty rest.

  • A long run of duties earns its rest afterwardsStrategichard or soft
  • A long run of hours earns its rest afterwardsStrategichard or soft

  The night-time angle is not a separate rule identity, it is this same minimum-rest check, with the night-time window and a longer rest value set as configuration rather than hardcoded.

  configured Strategic rostering →

• Element 8

  Minimum number of rest periods within a roster cycle

  Guarantee a minimum count of rest periods across the whole published cycle, not only between individual duties.

  • Off-duty periods are long enough to count as restStrategichard or soft
  • Days off come in runs, not scattered singlesStrategichard or soft

  configured Strategic rostering →