Start with output, not headcount
Write down the unit of work your business produces in a period — batches, tickets, deliveries, patients, classes, site tasks. Manpower planning is the arithmetic between that number and the productive hours you can actually buy.
The core formulas
- Required productive hours = units of work × standard hours per unit
- Available hours per person = shift hours × working days − leave − training − idle
- Shrinkage % = (leave + absenteeism + training + break) ÷ scheduled hours
- Required headcount = required productive hours ÷ (available hours × (1 − shrinkage))
- Replacement hires = opening headcount × expected attrition % for the period
Where the data comes from
- Attendance system: actual worked hours, absenteeism, overtime pattern
- Leave system: accrual liability and seasonal leave clustering
- Payroll: cost per productive hour by grade and location
- Exit data: attrition by department, tenure band and reason
Plan in three horizons
| Horizon | Question | Decision |
|---|---|---|
| Weekly | Is every shift covered? | Roster, overtime, temporary redeployment |
| Quarterly | Are we over or under capacity? | Hiring release, training, contract staff |
| Annual | What will the business need? | Budget, structure, skill mix, automation |
Warning signs in your own data
- Overtime above 10% of regular hours in a department for three months
- Leave balances rising while absenteeism also rises
- Attrition concentrated in the 0–12 month tenure band
- One location consistently outperforming another on cost per unit
This resource is shared for general guidance. Rules, rates and due dates change and vary by state and establishment — confirm the current position with your advisor before acting on it.
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