Checkpoint Staffing for a Three-Day Fair
You are assisting the traffic-in-charge for a three-day fair at a ground 7.2 km from the police station. The diversion has three checkpoints. The officer proposes 4 constables per checkpoint per shift, with three 6-hour shifts across the 18-hour duty day, plus 2 constables at the control room for the whole day. The station can spare only 24 constables daily, and standing orders require that 15 per cent of any spare strength be held back as reserve and not deployed. The fair organisers expect 4,500 visitors at peak, and the district crowd-management manual prescribes one constable per 250 visitors for queue and gate management, in addition to checkpoint duty. Reinforcements, if requested, can only arrive from the next day.
1. Test the officer's proposal against the available strength. Show the arithmetic and state the shortfall.
Read the worked answer
The proposal needs 3 checkpoints × 4 constables × 3 shifts = 36 constables for checkpoints, plus 2 at the control room = 38 deployed posts.
Available strength is 24, but the reserve rule bites before deployment: 15 per cent of 24 = 3.6, which must be rounded up (you cannot hold back a fraction of a person, and rounding down would breach the order) to 4. Deployable strength = 24 − 4 = 20.
Shortfall on the officer's plan = 38 − 20 = 18 constables, which is 47 per cent of the deployable strength. Separately, crowd management alone would require 4,500 ÷ 250 = 18 constables, so the officer's checkpoint plan plus the manual's crowd norm would need 38 + 18 = 56, and with a 15 per cent reserve on that total (8.4, rounded to 9) about 65. Against 20 deployable, the plan is not merely tight, it is arithmetically impossible. The correct answer to the officer is therefore not "we will manage" but a written request for reinforcement with these figures attached, and an interim plan for today.
2. Propose the best feasible deployment for the first day using only the 24 available constables, and state explicitly what risk you are accepting.
Read the worked answer
Hold back 4 as reserve, leaving 20. Keep 2 at the control room permanently, leaving 18 for the field. Put 2 constables at each of the three checkpoints per shift = 6 per shift; over three shifts that absorbs all 18, with zero relief and no one free to cover a constable who falls ill or needs a break. That is too brittle.
Better: 2 per checkpoint per shift (6 per shift), three shifts = 18, plus 2 control room = 20 deployed, reserve 4. The 4 reserves double as relief for meal breaks and emergencies across the 18-hour day. This meets checkpoint duty but cannot meet the manual's crowd norm of 18 constables for 4,500 visitors; we can supply effectively none for queue management.
The accepted risk is therefore crowd congestion at the gates, and it must be stated in writing, not absorbed silently. Mitigation for day one: ask organisers to provide trained volunteers and private security for queue and gate work under police supervision, stagger entry by time slots, keep one gate as an exit-only channel, and record the shortfall in the daily report so that reinforcement for days two and three is justified. Reducing the shift from 6 hours or the checkpoint strength below 2 would create a different and worse risk.
3. On day two, 3 constables report sick. Does the plan still hold? Justify with numbers and state the decision you would take.
Read the worked answer
New strength = 24 − 3 = 21. Reserve at 15 per cent = 3.15, rounded up to 4, leaving 17 deployable. Field requirement for 2 per checkpoint per shift is 6 per shift × 3 shifts = 18, plus 2 at the control room = 20. Against 17 deployable, the shortfall is 3 posts.
The plan does not hold unchanged. Options, in order of preference: first, request 3 constables from the district reserve or a neighbouring station, since this is a temporary three-day event and a written request on day two is reasonable; second, if no reinforcement is available, keep all three checkpoints manned at 2 per shift but shorten the duty day's span at the least-used checkpoint, closing it for the two hours when traffic counts are lowest, and use those hours of manpower to cover the control room; third, in the last resort, reduce the control room to one constable, which is the least risky post to thin because the checkpoint staff can reach it by wireless.
What must not be done is quietly deploying the reserve, because the reserve exists precisely for sickness and emergencies and emptying it leaves no capacity for a second absence. Any change should be recorded and reported, not improvised silently on the ground.