True Number of Staff needed
How Many Warehouse Workers Do You Actually Need? A Practical Labor Planning Guide for Phoenix Operations
“How many warehouse workers do we need?”
It sounds like a simple question.
Take the expected workload, divide it by how much one employee can produce, and you have your headcount.
Except warehouses don't operate inside spreadsheets.
Employees call out. New hires work more slowly while learning. Trucks arrive late. Equipment becomes unavailable. Orders aren't evenly distributed throughout the shift. Receiving gets slammed while picking is quiet. Then everything reverses three hours later.
And in Phoenix, an operation may also be dealing with long commutes, early shifts, seasonal demand, extreme heat in applicable environments, and an increasingly spread-out industrial workforce.
So the real question isn't simply:
“How many employees does our warehouse need?”
It's:
“How much labor capacity do we need, where do we need it, when do we need it, and how much variability can our operation absorb?”
That produces a much better workforce plan.
Start With Work, Not Headcount
Imagine two Phoenix warehouses.
Both employ 50 people.
Warehouse A processes relatively predictable daily volume with standardized products and stable schedules.
Warehouse B handles highly variable inbound shipments, thousands of SKUs, seasonal promotions, customer-specific requirements, and unpredictable order timing.
They have identical headcount.
They do not have identical labor requirements.
That's why comparing staffing levels with another warehouse can be misleading.
The better starting point is your own workload.
What Work Actually Happens Inside Your Warehouse?
A warehouse isn't one labor process.
Product may move through several stages:
Receiving → Unloading → Putaway → Replenishment → Picking → Packing → Staging → Shipping
There may also be inventory control, returns, cleanup, equipment support, quality checks, supervision, and other functions.
Each activity consumes labor differently.
So instead of asking:
“How many warehouse employees do we need?”
break the question down.
How much receiving labor do we need?
How much picking labor?
How much packing labor?
How much shipping labor?
Now workforce planning becomes operational.
The Foundation: Labor Hours
A useful starting point is calculating how many hours of work must be completed.
Suppose a warehouse estimates that tomorrow's workload requires approximately:
FunctionEstimated Labor HoursReceiving40Putaway24Picking96Packing72Shipping32Other Operational Work16Total280
These numbers are purely illustrative.
The important number is:
280 labor hours.
If every productive employee provided eight usable hours toward those activities, simple arithmetic would suggest:
280 ÷ 8 = 35 workers
But that doesn't necessarily mean scheduling exactly 35 people will work.
Eight Paid Hours Doesn't Necessarily Equal Eight Productive Hours
This is one of the biggest mistakes in warehouse labor planning.
An eight-hour shift isn't automatically eight hours of direct productive activity.
Time can be consumed by:
Startup.
Meetings.
Breaks.
Travel through the facility.
Training.
Waiting.
Equipment availability.
System delays.
Replenishment delays.
End-of-shift processes.
Other necessary activities.
Some of that time is unavoidable.
The objective isn't eliminating every nonproductive minute.
It's understanding how much productive capacity actually exists.
Measure Productive Hours Honestly
Suppose historical operating data shows that a particular eight-hour shift produces an average of 6.8 hours of usable direct activity for the work being modeled.
Then:
280 labor hours ÷ 6.8 productive hours ≈ 41.2 workers
Now your theoretical requirement is closer to 42 workers rather than 35.
That's a substantial difference.
The correct productivity assumptions will vary by operation.
Use your own data.
Productivity Rates Can Make Planning Even Better
Labor hours aren't always estimated manually.
Warehouses can connect workforce requirements to operating units.
For example:
Orders per labor hour.
Lines picked per labor hour.
Cases handled per labor hour.
Pallets unloaded per labor hour.
Units packed per labor hour.
Shipments processed per labor hour.
The correct measurement depends on the operation.
An Illustrative Picking Example
Suppose tomorrow's forecast includes:
4,800 units to pick
and your operation historically averages:
120 units per productive labor hour
The theoretical requirement would be:
4,800 ÷ 120 = 40 productive picking hours
If those assumptions are accurate, you now have a starting point for the picking workforce.
But be careful.
Averages Can Lie
Suppose the average is 120 units per hour.
That doesn't mean every employee produces 120 units every hour.
Maybe:
Experienced workers perform above the average.
New employees perform below it.
Certain product categories are slower.
Some zones require more travel.
Large orders behave differently from small ones.
Equipment availability changes throughput.
Volume arrives unevenly.
The average is useful.
But averages need context.
Segment Work When It Behaves Differently
Instead of one universal warehouse productivity rate, you may need separate assumptions.
For example:
Small-item picking.
Case picking.
Pallet picking.
Returns.
Special handling.
Different warehouse zones.
Different shifts.
Different order profiles.
The more differently work behaves, the less useful one average becomes.
Don't Build a Workforce Plan Around Your Best Employee
Every warehouse has someone who seems able to do the work of several people.
That's useful.
It's not necessarily a workforce-planning standard.
If your best employee picks 160 units per hour but the sustainable team average is 115, planning the department around 160 creates chronic understaffing.
Use repeatable performance.
Not exceptional performance.
New Employees Need a Ramp
Suppose you need 20 additional employees for peak season.
Hiring them doesn't instantly create the productive capacity of 20 experienced employees.
New employees may need:
Orientation.
Training.
Practice.
Coaching.
Time to learn the facility.
Time to understand systems.
Time to develop speed.
That means workforce planning needs to begin before the capacity is required.
Hiring Date and Capacity Date Are Different
This distinction is extremely important.
If peak demand begins November 1, you may need employees productive by November 1.
That can mean recruiting, hiring, onboarding, and training well before then.
The exact lead time depends on the job and operation.
Don't make:
Peak starts November 1
equal:
Start recruiting October 31.
Training Capacity Can Become the Bottleneck
Suppose you successfully recruit 40 new employees.
Great.
Can your operation effectively train 40 people simultaneously?
If you have:
Two trainers.
Limited equipment.
Limited training space.
Busy supervisors.
you may create chaos.
Sometimes staggered hiring creates more productive capacity than bringing everyone in at once.
Labor Planning Should Include Training Capacity
Before a major ramp, ask:
How many people can we onboard per day?
Who trains them?
How long before they can work independently?
What equipment is required?
How many experienced employees will be pulled away from production to help?
That last question matters.
Training new employees consumes some capacity from experienced employees.
Attendance Changes Scheduled Capacity
Suppose you need 50 employees operationally.
So you schedule exactly 50.
One calls out.
Another arrives late.
Now you're short before production begins.
That doesn't mean every warehouse should automatically overstaff by a fixed percentage.
It means workforce planning should use historical attendance data.
Know Your Show Rate
Track:
Employees scheduled.
Employees who arrive.
Employees who arrive on time.
Call-outs.
No-shows.
Early departures.
Then segment the information.
By shift.
Day.
Department.
Season.
Position.
Staffing source.
You may discover useful patterns.
Don't Automatically Schedule to the Theoretical Minimum
If a deadline is unforgiving and historical attendance shows some predictable loss of capacity, scheduling exactly to mathematical minimum may create unnecessary operational risk.
The appropriate buffer depends on the business, workload, historical performance, and consequences of being short.
The principle is simple:
Plan using reality, not perfect attendance.
But Don't Use Overstaffing to Hide Attendance Problems
There's another side.
If chronic absenteeism forces you to schedule dramatically more people than the work actually requires, investigate the attendance problem.
A staffing buffer can manage normal variability.
It shouldn't become permission to ignore a broken workforce system.
Volume Doesn't Arrive Evenly
Suppose your warehouse receives 10 trucks tomorrow.
That doesn't mean one arrives every 48 minutes.
Maybe six arrive during a narrow window.
Now receiving needs substantially more capacity during that period.
Daily headcount can look adequate while hourly headcount fails.
Plan Labor by Time Window
For more complex operations, break the day into blocks.
TimeReceivingPickingPackingShipping6–9 AMHighModerateLowLow9 AM–NoonModerateHighModerateLowNoon–3 PMLowHighHighModerate3–6 PMLowModerateHighHigh
This is illustrative, but it reveals something important.
The warehouse may have enough total labor and still have the wrong labor in the wrong place.
Cross-Training Creates Movable Capacity
This is where cross-training becomes operationally powerful.
Suppose receiving is overwhelmed at 8 AM.
By noon, inbound slows while picking increases.
Employees trained in multiple appropriate functions can move with the workload.
That creates flexibility without necessarily adding headcount.
Cross-Training Isn't “Everyone Does Everything”
That creates confusion.
Employees still need appropriate qualifications, instruction, and authorization for the work they perform.
Cross-training should be intentional.
A useful approach is creating a skills matrix.
EmployeeReceivingPickingPackingShippingEmployee A✓✓Employee B✓✓Employee C✓✓Employee D✓✓✓
Now supervisors know where capacity can move.
Supervisors Are Part of Capacity
Warehouse planning often counts direct labor while treating supervision as unlimited.
It isn't.
One supervisor may effectively manage a certain team size and workflow.
Double the workforce overnight and that same supervisor may suddenly spend the entire shift:
Answering questions.
Resolving confusion.
Assigning work.
Training.
Fixing mistakes.
Managing attendance.
The operation added labor but overwhelmed leadership.
More Workers Can Reduce Productivity
Imagine a small packing area designed for eight people.
You put 16 people inside it.
What happens?
Workers get in each other's way.
Equipment becomes unavailable.
Material flow gets congested.
Supervision becomes harder.
Productivity per employee can fall.
The question isn't:
“How many workers can we add?”
It's:
“How many workers can this process productively absorb?”
Find the Bottleneck Before Adding Labor
Suppose shipping is late every day.
Management assumes:
“We need more shipping employees.”
But investigation reveals shipping workers spend half their time waiting because picking isn't complete.
Adding shipping employees won't solve that.
The bottleneck is upstream.
Likewise, workers may be waiting for:
Equipment.
Inventory.
Replenishment.
System access.
Quality approval.
Dock availability.
More labor doesn't solve every capacity constraint.
Follow the Work
One of the most useful questions operations leaders can ask is:
“Where is the work waiting?”
Is product waiting for people?
Or are people waiting for product?
That distinction matters.
Measure Labor Utilization Carefully
Utilization can help identify unused capacity.
But don't chase 100% utilization blindly.
An operation with every employee constantly at maximum capacity may have no resilience for:
Volume changes.
Call-outs.
Equipment problems.
Rush orders.
Training.
Unexpected work.
Some operational flexibility can be valuable.
Separate Base Demand From Peak Demand
A warehouse might have:
Base demand — normal recurring workload.
Peak demand — predictable increases.
Surge demand — unusually large short-term spikes.
Emergency demand — unexpected disruptions.
Those workloads don't necessarily need identical workforce solutions.
Build a Core + Flexible Workforce
One possible framework is:
Core Workforce
Permanent employees supporting predictable baseline operations.
Flexible Capacity
Temporary employees, approved overtime, adjusted schedules, or other capacity for predictable variable demand.
Contingency Capacity
Plans for unexpected disruptions.
This doesn't prescribe a specific percentage.
Every operation is different.
Permanent Headcount Shouldn't Necessarily Equal Peak Headcount
Suppose your warehouse needs 60 people during normal periods but 85 during a short seasonal peak.
Maintaining 85 employees throughout the year may create unnecessary excess capacity.
But maintaining exactly 60 and waiting until peak week to react may create the opposite problem.
Forecasting helps determine the appropriate mix.
Temporary Staffing Can Function Like Variable Capacity
Temporary staffing can be particularly useful when workload is:
Seasonal.
Project-based.
Variable.
Growing but uncertain.
Temporarily elevated.
Temporary employees shouldn't automatically replace permanent workforce planning.
They can complement it.
Overtime Is Another Capacity Tool
Overtime can be extremely efficient for short-duration increases because existing employees already know the operation.
But sustained overtime deserves attention.
Repeated overtime may affect:
Fatigue.
Morale.
Attendance.
Retention.
Safety.
Total labor cost.
A few extra hours and months of structural overtime aren't the same workforce strategy.
Calculate the Cost of Capacity, Not Just Hourly Wage
Suppose one workforce option appears cheaper per hour.
But it creates:
Lower attendance.
More turnover.
Slower productivity.
More training.
Higher overtime elsewhere.
The hourly rate doesn't capture the full cost.
Warehouse managers should increasingly think in terms of:
Cost per productive labor hour
and, where possible:
Labor cost per unit of output.
Labor Cost Per Unit Can Change the Conversation
Suppose:
Workforce Model A
Lower hourly labor cost.
Higher turnover.
Lower productivity.
Workforce Model B
Higher hourly labor cost.
Better retention.
Higher productivity.
Which is cheaper?
You need output data to know.
That's why labor decisions shouldn't be made from wage rates alone.
Sales Forecasts Should Become Labor Forecasts
Warehouse managers shouldn't be the last people to learn that demand is increasing.
If sales knows:
A large customer signed.
A promotion is launching.
A new contract begins.
Volume is expected to increase.
Operations should know.
Then expected volume can become expected labor requirements.
Build a Rolling Workforce Forecast
It doesn't need to be complicated.
HorizonOperational QuestionTomorrowDo we have enough people for known workload?Next WeekWhat shipments/orders/projects are expected?30 DaysAre staffing levels aligned with forecast demand?60 DaysDo we need recruiting or cross-training?90 DaysIs demand becoming permanent?Peak SeasonWhat capacity must be ready before volume arrives?
The further out you can reasonably see, the more options you have.
Forecast Ranges Instead of Pretending You Know the Future
A forecast isn't a promise.
Instead of:
“We'll need exactly 72 employees.”
consider scenarios.
Low Volume
Expected workforce requirement.
Base Volume
Most likely workforce requirement.
High Volume
Additional capacity plan.
Now operations has options if demand changes.
Use Trigger Points
A useful workforce plan can define actions before they become emergencies.
For example:
If volume reaches Level A → use normal workforce.
If volume reaches Level B → offer appropriate overtime.
If volume reaches Level C → activate temporary capacity.
If sustained volume remains above Level C → evaluate permanent hiring.
The actual triggers should be based on your operation.
This converts workforce planning from reaction into process.
Don't Forget Backlog
Daily workload isn't always the full workload.
If yesterday's unfinished work rolls into today, today's workforce requirement increases.
Track backlog separately.
Otherwise, a warehouse can appear properly staffed for today's orders while falling further behind every day.
Backlog Growth Is a Signal
If backlog consistently increases, one or more things may be wrong:
Capacity is insufficient.
Productivity assumptions are unrealistic.
Equipment is constrained.
Processes are inefficient.
Attendance is poor.
Volume forecasts are wrong.
Something upstream is failing.
Temporary labor may help clear the backlog.
But investigate why it formed.
Phoenix Commutes Affect Capacity Too
A schedule isn't useful if you can't reliably staff it.
Phoenix-area warehouses can draw from very different candidate pools depending on location.
A facility in Tolleson may recruit differently from one in Chandler.
A Goodyear operation may compete for employees throughout the West Valley.
A Buckeye facility may benefit from building a local workforce rather than depending entirely on long-distance commuting.
Geography is part of workforce planning.
Early Shifts Need Additional Attention
A 5:00 AM shift changes the recruiting equation.
Candidates need transportation and routines that work at that hour.
If an operation consistently struggles to staff an early shift, don't merely increase recruiting volume.
Examine:
Candidate geography.
Schedule design.
Pay.
Transportation reliability.
Shift leadership.
Job expectations.
Retention.
The problem may be structural.
Arizona Heat Can Affect Labor Planning
Phoenix operations involving outdoor work or hot environments should incorporate actual working conditions into workforce planning.
Employers should follow applicable safety requirements and use appropriate procedures for the conditions and work being performed.
Heat can influence:
Work pace.
Break requirements.
Fatigue.
Scheduling.
Employee experience.
Safety.
A workforce model that ignores the real environment isn't a realistic model.
Protect Your Most Reliable Employees
When a warehouse is understaffed, the same people often absorb the difference.
Your strongest employees:
Work overtime.
Train new hires.
Cover missing coworkers.
Move between departments.
Take difficult assignments.
That's useful temporarily.
It's dangerous permanently.
Reliability Shouldn't Become a Penalty
If being dependable means someone constantly receives more work without support, recognition, development, or appropriate reward, you risk burning out the employees keeping the operation together.
Workforce planning protects your best people by reducing the need for constant heroics.
Review Staffing After the Shift
Don't only forecast.
Learn.
After a meaningful workload period, compare:
Forecast volume.
Actual volume.
Planned labor hours.
Actual labor hours.
Attendance.
Overtime.
Productivity.
Backlog.
Quality.
Safety issues.
What happened?
Forecast Error Is Valuable
Suppose you planned 400 labor hours.
You needed 470.
Don't simply say:
“We were understaffed.”
Ask why.
Was volume higher?
Productivity lower?
Attendance worse?
Training slower?
Equipment unavailable?
The forecast wasn't merely wrong.
It produced information.
Build Better Forecasts Over Time
The goal isn't predicting tomorrow perfectly.
It's reducing surprises.
Every week produces new data.
Over time, your workforce model should learn:
Which days are heavier.
Which customers create unusual work.
Which shifts struggle with attendance.
How quickly new hires become productive.
How seasonality behaves.
How much overtime is sustainable.
How temporary employees perform.
That creates a smarter operation.
How Flat Staffing Supports Warehouse Workforce Planning
Flat Staffing has served the Phoenix Valley since 2018, supporting workforce needs across warehousing, logistics, distribution, manufacturing, automotive operations, events, and general labor.
When a warehouse says:
“We need 20 people.”
the number matters.
But so does the reason behind it.
Is this:
A permanent increase?
Peak demand?
A backlog?
A project?
A shipment?
Call-out coverage?
Seasonal volume?
A new customer?
Those answers help determine what kind of workforce strategy makes sense.
Give Your Staffing Partner the Forecast
Staffing agencies can generally plan more effectively when they know what's coming.
Instead of:
“I need 30 people tomorrow.”
when possible, communicate earlier:
Expected headcount.
Possible high-volume headcount.
Schedule.
Duration.
Job responsibilities.
Working conditions.
Required qualifications.
Potential start dates.
Even if the forecast changes, advance information can improve recruiting preparation.
Share What Happens After Workers Arrive
Your staffing partner should know:
Who performed well?
Who returned?
Who struggled?
Who no-showed?
What skills were valuable?
Why did people leave?
Which shifts retain workers?
The staffing process improves when operational outcomes flow back into recruiting.
Leadership Behind Flat Staffing
Flat Staffing is led by Nino Mihilli, and workforce planning reflects a simple management principle:
Don't manage the number. Understand what creates the number.
If a report says:
“We need 50 workers.”
ask why.
What volume created that requirement?
What productivity assumption?
What attendance assumption?
What schedule?
What backlog?
What training level?
What bottleneck?
Numbers are useful.
Understanding the system behind them is much more powerful.
Once management understands what creates the workforce requirement, the business can begin improving it.
You can learn more about Nino's approach to business, operations, and leadership at NinoMihilli.com.
The Bottom Line
Determining warehouse headcount shouldn't begin with:
“How many employees did we have last year?”
And it shouldn't end with:
“We probably need 10 more people.”
Start with the work.
Measure expected volume.
Translate volume into labor hours.
Use realistic productivity.
Account for the learning curve.
Understand attendance.
Identify bottlenecks.
Plan labor by department and time.
Cross-train appropriately.
Protect supervisory capacity.
Separate base demand from peak demand.
Use overtime strategically.
Use flexible staffing strategically.
Watch backlog.
Review actual results.
Then improve the model.
Because the best warehouse workforce isn't necessarily the biggest workforce.
It's the workforce that provides enough productive capacity to complete the work safely, reliably, and efficiently without constantly burning out the people who make the operation run.
Frequently Asked Questions
How do I calculate how many warehouse employees I need?
Start by estimating workload by function and translating that workload into required labor hours using your operation's historical productivity. Then account for factors such as training, attendance, workflow constraints, supervision, and when during the shift the work occurs. A simple workload divided by eight hours may substantially oversimplify the requirement.
Should warehouses schedule extra workers for call-outs?
Businesses should use their own historical attendance and show-rate data when planning workforce capacity. Some operations may need contingency capacity when deadlines are inflexible, but excess scheduling shouldn't become a substitute for addressing chronic attendance problems.
How far in advance should warehouses hire for peak season?
There is no universal lead time. Work backward from when employees must be productive, considering recruiting time, onboarding, training capacity, learning curves, and expected volume. The important distinction is that an employee's start date and the date they reach expected productivity may not be the same.
Should warehouses use overtime or temporary employees for peak demand?
Either can make sense depending on duration, workload, employee availability, productivity, training requirements, total cost, and operational conditions. Short increases may be handled effectively through overtime, while longer or larger variable demand may justify temporary capacity or a combination of approaches.
What warehouse staffing metrics should employers track?
Useful metrics can include volume, labor hours, productivity by function, attendance, on-time arrivals, overtime, backlog, training time, turnover, returning temporary workers, quality, and labor cost per unit of output where appropriate.










