Home / Flow & productivity

Manpower staffing and coverage factor

Enter positions, shifts, contracted hours and absences to get the required headcount, the coverage factor per position, the annual cost and what reducing absenteeism saves.

Pre-sizing and estimating tool: results do not replace design, calculations or reports signed by a licensed professional, nor verification against the applicable codes and standards.

Preliminary estimate
Operation
Hours and absences per employee
Costs and target
Economic analysis
—Required headcount
—

An employee’s year

From contracted hours to hours actually available at the position.

Tap the chart to see the values.

Headcount versus absenteeism

People needed to staff the positions with absenteeism from 0% to 10%.

Tap the chart to see the values.

Project payback

Cash flow of the improvement: investment in year 0 and annual savings escalated at the rate entered, discounted at the MARR.

Tap the chart to see the values.

The report gathers this page's inputs, results, equations, assumptions and references, with fields for project, engineer and revision. In the print dialog, choose Save as PDF.

Method, assumptions and references

Equations used

Hours needed = positions × shifts × hours per shift × operating days per week × 52.18
Contracted hours = weekly hours × 52.18; vacation = days ÷ 7 × weekly hours; holidays = days × weekly hours ÷ 5
Available hours = (contracted − vacation − holidays) × (1 − absenteeism) − training
Headcount = hours needed ÷ available hours; coverage factor = headcount ÷ (positions × shifts)

Assumptions and limits

  • Every position needs one person present for the whole shift; meal breaks are covered within the arrangement or do not stop the position.
  • Overtime is not used to cover absences; the actual rotation (such as 4-on-4-off or DuPont) must be built within labor law and any union agreement.
  • Annual cost per employee includes wages, payroll taxes and benefits.

Standards and technical documents

  • International Labour Office. Introduction to Work Study, 4th ed., 1992 (planejamento de pessoal e tolerâncias)
  • Knauth, P. Designing better shift systems. Applied Ergonomics 27(1), 1996
  • ISO 22400-2:2014: KPIs (mão de obra e utilização)

U.S. regulations

  • Fair Labor Standards Act: overtime above 40 hours per week; no federal requirement for paid vacation or holidays
  • Family and Medical Leave Act: up to 12 weeks of job-protected leave for eligible employees
  • State laws on paid sick leave affect absenteeism planning

Frequently asked questions

How many people does a 24/7 position need?

With 40-hour weeks, 14 days of vacation, 10 paid holidays and 3% absenteeism, each continuous position needs about 4.8 people.

What is a coverage factor?

It is the ratio of required headcount to position-shifts. It shows how many extra people are needed to cover days off, vacation, holidays and absences.

What does one point of absenteeism cost?

Each point of absenteeism raises the required headcount by about 1%. In a crew of 100 people costing $62,000 each per year, that is roughly $65,000 per year.