Staffing a 24-Hour Post With 12 Men Standing
You are preparing the watch roster for a 24-hour checkpost. Sanctioned strength is 18. On Day 1 the position is: 3 on sanctioned leave (one returns on Day 4, two return on Day 6), 2 on a ten-day training course, and 1 on medical leave with no stated return date. Of the 12 who remain, one carries a doctor's certificate barring night duty for four weeks. The standing requirement is 3 persons on duty in every shift - two at the gate and one in the control room - across three 8-hour shifts (06:00–14:00, 14:00–22:00, 22:00–06:00). No one may work more than one shift in a day, and no one may work more than six consecutive days without a full rest day. On Days 4 and 5 a VIP convoy will pass, raising the requirement to 5 persons per shift. The Superintendent wants a one-page answer: can the week be staffed to standard, and what margin is left?
1. Compute the person-shifts required for the seven days (base requirement plus convoy surge) and the person-shifts available. Is the week feasible, and what is the margin in shifts?
Read the worked answer
Requirement
- Base: 3 persons × 3 shifts = 9 person-shifts a day; 9 × 7 = 63.
- Surge: extra 2 persons × 3 shifts = 6 a day, on Days 4 and 5 only = 12.
- Total = 75 person-shifts.
Availability (six duty days, then one rest day, so six shifts per person per week)
- 12 men present all week: 12 × 6 = 72.
- The man returning on Day 4 works Days 4–7 = 4 shifts.
- The two returning on Day 6 work Days 6–7 = 2 shifts each = 4.
- Total = 80 person-shifts.
Verdict: 80 against 75 leaves a margin of 5 shifts, which is less than one full man-week. The week can be staffed to standard only if the Day 4 and Day 6 returns actually report and no one else goes sick. Say so plainly, and ask for the district reserve to be kept on two hours' notice on Days 4–5.
2. A sentry argues that the night-duty restriction is only advisory, and that the restricted man's six shifts can be counted as night cover 'on paper'. Test that argument with numbers and state your ruling.
Read the worked answer
Run the night column separately.
- Night shifts needed: 3 posts × 7 nights = 21 night person-shifts.
- Night-capable pool: 11 of the 12 present (one barred) plus the Day 4 returnee (4 shifts) and the two Day 6 returnees (2 shifts each) = 66 + 4 + 4 = 74 night-capable person-shifts.
74 against 21 is nearly three and a half times the requirement. The restriction therefore costs nothing numerically - the roster holds on the plain arithmetic without touching the certificate. That is exactly why the argument fails: the man is not needed on nights, so there is no operational excuse for breaching a medical instruction.
Ruling: keep him on 06:00–14:00 and 14:00–22:00 only, and record the certificate in the roster file so that the next relief officer cannot quietly reverse it.
3. Two options are on the table: (i) cancel the rest days of four men over the convoy period; (ii) ask the district lines for two men on deputation for Days 4–5. Which do you recommend, and on what arithmetic and rule-based grounds?
Read the worked answer
Option (i) creates a debt larger than the margin. Four men × two cancelled rest days = 8 shifts of compensatory rest owed. The week's margin is only 5 shifts, so honouring the debt inside the same week leaves a shortfall of 3 shifts - and pushing the debt into the next week breaches the six-consecutive-day rule rather than solving it.
Option (ii) is bounded and lawful. Two men for two days = 4 shifts, taking the margin from 5 to 9, and the arrangement ends when the convoy passes.
Recommend (ii), with a written request copied to the range office, and a fallback that the control-room post may be single-manned outside convoy hours only with the Superintendent's written authorisation, logged hour by hour. Do not approve rest-day cancellation as a routine device; it converts a staffing problem into a discipline problem.