Muster Forecast and the Emergency Buffer
A closed prison has a certified capacity of 540. Monday morning muster is 512. The committals and discharges office gives this forecast: Tuesday +14 committals, −10 discharges; Wednesday +9 committals, −12 discharges, −3 transfers to another prison; Thursday +11 committals, −8 discharges, plus 6 prisoners returning from temporary release at 18:00. Assume no other movements. The Governor's operating rule is that at least 5% of certified capacity must remain free as an emergency buffer. Separately, 38 of Monday's prisoners are doubled in cells designed for one; policy caps doubling at 8% of the current muster.
1. Calculate the Thursday evening muster and the number of free places. Is the emergency buffer being met?
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Step through the movements:
- Monday: 512
- Tuesday: 512 + 14 − 10 = 516
- Wednesday: 516 + 9 − 12 − 3 = 510
- Thursday: 510 + 11 − 8 + 6 = 519
Free places: 540 − 519 = 21.
Buffer required: 5% of 540 = 27 places.
21 < 27, so the buffer is not met - the prison is 6 places inside its own rule.
The calculation matters more than the headline number: the buffer is a rule, not an aspiration, and being 6 places short is the trigger for escalation even though no cell is actually empty-blocked or over capacity.
2. What is the doubling rate on Monday, and would it be breached if 20 committals arrived on Friday and 6 of them had to be doubled? Show the figures.
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Monday: 38 ÷ 512 = 7.42% (or against Thursday's 519, 38 ÷ 519 = 7.32%) - inside the 8% cap either way.
Friday scenario: 519 + 20 = 539 muster; doubled prisoners 38 + 6 = 44.
- 44 ÷ 539 = 8.16%
- The cap is 8% of 539 = 43.12, i.e. a maximum of 43 doubled prisoners.
Result: breach by one prisoner. That is a real breach even though it looks trivial - the cap is expressed as a percentage of muster, so it moves as muster moves, and a single prisoner over the line is still over the line. The correct response is to find a single-cell place (transfer, earlier discharge, or use of a spare place elsewhere) rather than to round down. Note also that the doubling calculation and the buffer calculation must both be run: 539 also leaves only 1 free place against a required 27.
3. Using your figures, set out the options you would put to the Governor and state the limits on your own authority as a recruit.
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Options to restore the buffer (need at least 6 places by Thursday, 21 or more if Friday's 20 committals are confirmed):
- Bring forward the 3 Wednesday transfers to Tuesday and ask for a further 3 - needs the transfers section and the receiving prison to agree.
- Accelerated discharge review for prisoners within days of release - a governor/IPS decision, not an operational one.
- Request places in another institution for the Friday committals.
- Stagger committals across Friday and Saturday so the peak is never reached.
Limits on my authority: as a recruit I do not vary the buffer, authorise doubling above the cap, or decide transfers. My job is to produce the figures accurately, flag the breach clearly and in time, note which option each decision-maker owns, and record the instruction I am given. If I am told to proceed anyway, I confirm it in writing to the Chief Officer.