A / FT-HEAVY TEAM
80% FT / 20% PT
16 FT + 4 PT = 20 people
EXPERIMENT 04 / POLICIES / THE FT/PT CONUNDRUM
Same 20 people.
Which contract mix fits?
An 80% full-time / 20% part-time team can have too many people in a quiet period. Could 40% FT / 60% PT cover the same work with fewer excess hours? Start with a shop, three time blocks and the actual shifts.
01 / SAME DEMAND. DIFFERENT CONTRACT COMMITMENTS.
A shop open 9am–9pm.
There are 20 employees in both teams. Each FT works 8 hours/day, 40 hours/week; each PT works 4 hours/day, 20 hours/week. The same day repeats five days a week. All figures below follow the assumptions you set.
Opening · 9am–1pm10people needed
Four hours
Four hours
Middle · 1pm–5pm8people needed
Four hours
Four hours
Closing · 5pm–9pm10people needed
Four hours
Four hours
B / TEST A DIFFERENT MIX
40% FT / 60% PT
8 FT + 12 PT = 20 people
The denominator matters: 40/60 means eight FT and twelve PT employees out of twenty. It does not mean 40% of paid hours. We are comparing two possible contract structures, not shortening existing FT contracts with a slider.
THE CASE / 5-MINUTE EXPLORATION
Fictional teaching exampleStart with the situation.
The situation
Twenty employees cover a 9am–9pm shop. Demand is ten people at opening, eight in the middle and ten at closing.
Try this first
Compare 80/20 with 40/60 using the mix slider. Then try 20/80, or raise middle demand to twelve.
What to look for
See why the best-fitting mix needs enough FT core coverage and dependable PT shifts—not just a higher PT percentage.
Go to the experiment ↓Captioned animation · no sound needed
New to the terminology? Start here.
- FT / PT
- Full-time / part-time. Here FT means 8 hours/day, 40/week; PT means 4 hours/day, 20/week.
- 40/60 mix
- 40% FT and 60% PT by employee headcount: 8 FT and 12 PT out of 20.
- Headcount versus hours
- Twenty people can commit different total hours depending on their contracts. At 40/60 here, FT provides 57.1% of paid hours.
- Surplus or uncovered hours
- People-hours above or below the work requirement. Four people missing for four hours means sixteen uncovered people-hours.
02 / MOVE THE MIX. WATCH THE SHIFTS.
Keep 20 people. Change the FT/PT mix.
Here is the actual day.
FT covers the long span. PT covers the opening or closing block. The coloured bars below are shifts—not demand.
CHECK THE RESULT
People scheduled versus people needed.
FT PT Demand
Employee headcount · always 20
Demand covered
Above demand / dayPeople-hours, not additional employees
Paid hours / day
See the hourly data
| Starting | Needed | FT | PT | Total | Above | Below |
|---|
03 / FOLLOW THE CONTRACTED HOURS INTO THE BUDGET
The same headcount can mean a different wage bill.
Both start at $30/hour. The difference initially comes from hours committed, not a cheaper PT rate. Annual wages = daily wages × 5 days × 52 weeks.
Your selected mix · annual wages
80/20 benchmark · annual wages
Annual difference from 80/20
04 / TRY TO BREAK THE 40/60 ANSWER
What would make another mix better?
Try a middle-period demand of 12: the lowest-cost fully covered mix becomes 60/40 at equal hourly wages. Limit PT availability or increase its wage, and the answer can change again.
| FT / PT by people | FT + PT employees | Surplus h/day | Uncovered h/day | Wages/week | Assessment | Explore |
|---|
Why 40/60 fits the starting example—and the limits of this comparison
In the starting example, each edge period gets ten people: half of the FT group plus half of the PT group. Only the two FT groups cover 1pm–5pm, when both are present. Eight FT employees are therefore needed for middle demand of eight. Eight out of twenty is 40%; the other twelve employees are PT. A 20/80 mix leaves just four FT employees in the middle, short by four people for four hours.
We compare eleven headcount mixes in steps of 10%, with FT employees split equally between 9am–5pm and 1pm–9pm. PT employees cover 9am–1pm or 5pm–9pm. Every person works one shift. We rank fully covered mixes that meet the FT policy floor by wages, then surplus hours, then more FT employees. This tests these specific shift patterns, not every possible roster or an organisation-wide optimal ratio.
THE POLICY CONVERSATION
Match commitments
to the shape of work.
40/60 is a concrete answer to this example, not a target to copy into every business. More PT does not always help: too little core coverage creates a different problem. Availability, skills, employee preferences and the real work need to support the mix.
Before calling the overlap waste, check whether training, replenishment, handovers or other tasks are missing from demand. A different contract structure is a workforce planning decision, not an instruction to cut existing employees’ hours.
Read the policy field note ↗Assumptions and what a real workforce plan must add
This fictional shop operates 9am–9pm on five days per week. All twenty employees repeat the same shifts on those days for 52 weeks. FT contracts are 8 hours/day and 40 hours/week; PT contracts are 4 hours/day and 20 hours/week. These are chosen teaching assumptions, not definitions for every employer. Every scheduled hour is treated as paid and available for work.
Breaks, leave and relief coverage, skills, supervision, other shift starts, split shifts, individual preferences, weekends, public holidays, penalties, overtime, wage on-costs, employment requirements, recruitment and training costs are outside this comparison. A seven-day operation needs a separate weekly roster. The hourly wages and service demand are the same for the 80/20 benchmark and your selected mix.
A lower wage figure only supports a like-for-like coverage comparison when both mixes meet the entered demand. The total headcount stays twenty even with no demand: existing contract commitments do not disappear when demand falls.