24/7 Staffing Coverage Model

SHIFT STRUCTURE — 10-HR OVERLAPPING SHIFTS

DAY SHIFT

0600–1600

All regular pay.
0 hrs night differential.

EVENING SHIFT

1400–0000

6 hrs night differential
(1800–0000, +10%).

NIGHT SHIFT

2200–0800

8 hrs night differential
(2200–0600, +10%).

Three overlapping 10-hour shifts cover 24 hours with a 2-hour handoff overlap at each transition (1400–1600, 2200–0000, 0600–0800). Overlap periods allow outgoing and incoming crews to share situational awareness before turnover — a feature of this model, not waste. Each person works 4 shifts per week × 10 hours = 40 hours, with 3 consecutive days off every week.

CONTINGENCY BUFFER (SICK / LEAVE / EMERGENCIES)

25%

0% (theoretical) OPM RECOMMENDS ~25% 40% (extreme)

THE ACTUAL MATH

HOURS TO COVER (1 POSITION x 24/7/365)

8,760 hrs/yr

GROSS FTE HOURS (40 hrs/wk x 52 wks)

2,080 hrs/yr

OPM MANDATORY LEAVE (PER PERSON)

Annual Leave (avg)20 days / 160 hrs

Sick Leave13 days / 104 hrs

Federal Holidays (11 days × 10 hrs) 11 days / 110 hrs

TOTAL MANDATORY LEAVE 44 days / 374 hrs

NET AVAILABLE HOURS (BEFORE BUFFER)

82% availability

1,706 hrs

EFFECTIVE HOURS AFTER 25% BUFFER

62% of gross FTE time

1,280 hrs

PEOPLE NEEDED PER POSITION

8,760 / 1,280 = 6.85 -> round up

7 FTE

Holiday note: Federal holidays credit the employee for their full scheduled workday. At 10 hours per shift, each holiday costs 10 hours of leave instead of 8 — adding 22 extra leave hours per year compared to an 8-hour model (11 days × 2 hrs). This slightly reduces net availability from 83% to 82%.

RESULT AT 25% BUFFER

OPERATORS

21

3 positions x 7

SUPERVISORS

7

1 position x 7

TOTAL STAFF

28

full 24/7 coverage

COMPARED TO 8-HOUR SHIFTS

Shift times 0600–1600 / 1400–0000 / 2200–0800

Days per week 4 on · 3 off

Consecutive days off 3 (guaranteed)

Holiday hours (per day) 10 hrs

Annual mandatory leave 374 hrs

Net available hrs/yr 1,706 hrs

Shift handoff overlap 2 hrs per transition

Annual leave = shift-days 16 shift-days

FTE per position (25% buf) 7 (same)

Total headcount (25% buf) 28 (same)

The headline staffing numbers are nearly identical between 8-hour and 10-hour models at the same buffer percentage. The real differences are schedule quality (3 consecutive days off vs. irregular patterns), handoff depth (2-hour overlap for situational awareness), and leave accounting (160 hours of annual leave = 16 shift-days instead of 20 — same hours, fewer "days off" psychologically).

OPM SHIFT DIFFERENTIAL RULES (GS EMPLOYEES)

NIGHT DIFFERENTIAL

+10%

6:00 PM – 6:00 AM

5 CFR 550.122

EVE shift: 6 of 10 hours qualify (1800–0000).
NGT shift: 8 of 10 hours qualify (2200–0600).
DAY shift: 0 hours qualify.

SUNDAY PREMIUM

+25%

Regularly scheduled Sunday work

5 CFR 550.171

Applies to the full shift if any part falls on Sunday. In a fair rotation every crew shares Sundays equally.

In a properly structured rotating schedule every crew shares nights and weekends equally — so preference issues largely self-resolve. Shift attractiveness does not change your headcount math unless you allow opt-outs. A fair rotation makes this a morale and recruiting problem, not a staffing number problem.

BOTTOM LINE

CONSERVATIVE (25% BUFFER)

Operators: 21

Supervisors: 7

Total: 28

ROBUST (30% BUFFER)

Operators: 24

Supervisors: 8

Total: 32

This is the number of people dedicated to shift coverage for a 4-person rotation (3 operators + 1 supervisor) running 24/7/365. At 25% buffer the math lands at 28 people; at 30% it rises to 32. Your total headcount will be larger — personnel who carry other primary duties (admin, training, projects, ancillary ops) are also qualified on the rotation and step in when a shift rotator is on leave or unavailable. Those dual-role personnel are doing productive work the rest of the time; they are not idle buffer.

EXAMPLE: TWO-WEEK ROSTER — 80 HRS PER PERSON

DAY 0600–1600

EVE 1400–0000

NGT 2200–0800

BUF On-call buffer

OFF Rest day

7 TEAMS · 28 PEOPLE TOTAL · 8 SHIFTS EACH · 80 HRS EACH · 6 REST DAYS EACH

The 25% buffer is built directly into this rotation. With 7 teams and only 3 shift slots per day, exactly 1 team is on standby (BUF) every day — that is the buffer. No separate broader pool needed for routine coverage; the math closes with all 28 people in the active rotation. Personnel carrying other primary duties can still supplement when the buffer is consumed by actual leave or incidents.

	— WEEK 1 (APR 6–12) —							— WEEK 2 (APR 13–19) —
TEAM	MON 6	TUE 7	WED 8	THU 9	FRI 10	SAT 11	SUN 12	MON 13	TUE 14	WED 15	THU 16	FRI 17	SAT 18	SUN 19
ALPHA 3 OPS · 1 SUP	DAY	OFF	OFF	OFF	BUF	NGT	EVE	DAY	OFF	OFF	OFF	BUF	NGT	EVE

BRAVO 3 OPS · 1 SUP	EVE	DAY	OFF	OFF	OFF	BUF	NGT	EVE	DAY	OFF	OFF	OFF	BUF	NGT

CHARLIE 3 OPS · 1 SUP	NGT	EVE	DAY	OFF	OFF	OFF	BUF	NGT	EVE	DAY	OFF	OFF	OFF	BUF

DELTA 3 OPS · 1 SUP	BUF	NGT	EVE	DAY	OFF	OFF	OFF	BUF	NGT	EVE	DAY	OFF	OFF	OFF

ECHO 3 OPS · 1 SUP	OFF	BUF	NGT	EVE	DAY	OFF	OFF	OFF	BUF	NGT	EVE	DAY	OFF	OFF

FOXTROT 3 OPS · 1 SUP	OFF	OFF	BUF	NGT	EVE	DAY	OFF	OFF	OFF	BUF	NGT	EVE	DAY	OFF

GOLF 3 OPS · 1 SUP	OFF	OFF	OFF	BUF	NGT	EVE	DAY	OFF	OFF	OFF	BUF	NGT	EVE	DAY

ALPHA

Op A-1

Op A-2

Op A-3

Sup A

BRAVO

Op B-1

Op B-2

Op B-3

Sup B

CHARLIE

Op C-1

Op C-2

Op C-3

Sup C

DELTA

Op D-1

Op D-2

Op D-3

Sup D

ECHO

Op E-1

Op E-2

Op E-3

Sup E

FOXTROT

Op F-1

Op F-2

Op F-3

Sup F

GOLF

Op G-1

Op G-2

Op G-3

Sup G

The schedule follows a clean 7-day cycle: each team works 1 day, rests 3, works 3, repeating every week. Every team rotates through all shift types (DAY → BUF → NGT → EVE) with no team permanently stuck on nights or weekends. Each team works exactly 8 shifts = 80 hours over the fortnight, with 6 rest days including at least one 3-day consecutive block per week. When a team member is on annual leave or TDY, a qualified person from outside the active rotation fills the slot — personnel carrying other primary duties who maintain rotation currency.

10-HOUR SHIFT COVERAGE ANALYSIS