A capacity model tells you how many productive FTE you need.

A workforce forecast tells you whether you will actually have them.

That distinction is important.

Suppose an operation requires:

70 productive FTE next month

and currently has:

72 employees

At first glance, staffing appears sufficient.

But what if:

  • 5 employees are expected to leave?
  • 10 new hires are still in training?
  • Another 8 employees are only partially productive because they are ramping up?
  • Volume is forecast to increase next month?
  • The process is becoming more complex?

The business may have 72 people on paper and still be meaningfully understaffed.

A better workforce forecast connects:

Demand

↓

Required Productive FTE

↓

Opening Headcount

↓

Hiring

↓

Training

↓

Ramp-Up

↓

Attrition / Releases

↓

Effective Productive FTE

↓

Over / Under Staffing

That creates a much more realistic view of future workforce capacity.

Capacity Planning vs Headcount Forecasting

These are related but different exercises.

Capacity Planning

Answers:

How much productive capacity do we need?

For example:

Required workload = 50,000 cases

Productive capacity per FTE = 800 cases per month

Required productive FTE:

50,000 ÷ 800 = 62.5 FTE

Headcount Forecasting

Answers:

How many effective resources will we actually have?

For example:

Opening headcount = 70

Attrition = -5

New hires = +10

But only 40% of the new hires are productively effective during the month.

The operation's effective productive FTE may therefore be very different from its gross headcount.

Both calculations are needed.

Step 1: Forecast the Workload

The first input is future demand.

Suppose monthly transaction volume is expected to grow:

MonthForecast Volume
January50,000
February52,000
March55,000
April58,000
May60,000
June63,000

The forecast could come from:

  • Historical trends
  • Customer growth
  • Membership growth
  • Sales projections
  • Seasonal patterns
  • New product launches
  • Contracted business volumes
  • Management assumptions

The method depends on the business.

What matters is that the workforce model uses an explicit volume assumption rather than assuming demand will remain constant.

Step 2: Include Backlog Requirements

Incoming volume is not always the full workload.

Suppose March has:

Forecast incoming volume = 55,000

Existing backlog = 8,000

Management wants to reduce backlog by:

2,000 cases

Then required March output becomes:

55,000 + 2,000 = 57,000 cases

This is the workload the staffing model should support.

Without the backlog target, the operation may staff only to stabilize demand rather than improve service levels.

Step 3: Convert Workload into Required FTE

Suppose one fully productive FTE can process:

800 cases per month

Then:

Required Productive FTE = Required Output ÷ Capacity per FTE

For 57,000 cases:

57,000 ÷ 800 = 71.25 FTE

So the operation requires approximately:

72 productive FTE

depending on the organization's rounding and staffing rules.

For a complete explanation of this calculation, read:

How to Calculate Workforce Capacity: From Headcount and Productive Hours to Required FTE

Step 4: Build the Required-FTE Forecast

Apply the same logic to every month.

Assume:

Capacity per productive FTE = 800 transactions per month

MonthRequired OutputRequired Productive FTE
Jan50,00062.5
Feb52,00065.0
Mar57,00071.3
Apr58,00072.5
May60,00075.0
Jun63,00078.8

Now we know how much productive capacity the business needs.

The next step is forecasting how much it will actually have.

Step 5: Start with Opening Headcount

Suppose January begins with:

70 employees

This becomes the opening gross headcount.

But gross headcount should not automatically be treated as productive FTE.

Some employees may be:

  • In training
  • On long-term absence
  • Working partial allocation
  • Assigned to non-production activity
  • Still ramping

Therefore, the model should track both:

Gross HC

and:

Effective Productive FTE

Step 6: Include Attrition

Suppose historical attrition is:

2% per month

A simple model might estimate:

Expected Attrition = Opening HC × Attrition Rate

If January begins with:

70 employees

Expected attrition:

70 × 2% = 1.4 employees

For planning, the business may round this or maintain decimal expected attrition in the model.

However, attrition rarely occurs perfectly every month.

A forecast represents an expectation, not a guarantee.

Voluntary vs Planned Releases

It can be useful to separate:

Attrition

Unexpected or statistically forecast employee exits.

Planned Releases

Known reductions such as:

  • Contract completion
  • Planned restructuring
  • End of temporary assignments
  • Scheduled transfers

For example:

Expected attrition = 2 FTE

Planned transfer = 3 FTE

Total expected reduction:

5 FTE

Keeping them separate helps management distinguish forecast uncertainty from confirmed workforce changes.

Step 7: Add Planned Hiring

Suppose management plans to hire:

MonthNew Hires
Jan0
Feb10
Mar5
Apr10
May0
Jun0

Gross closing headcount could be calculated as:

Closing HC = Opening HC + Hires − Attrition − Releases

That is useful.

But it is not yet a capacity forecast.

New hires usually do not become fully productive immediately.

Step 8: Account for Training

Suppose new employees require:

1 week of training

During training, they may contribute little or no normal production capacity.

Therefore:

10 employees hired does not automatically mean:

+10 productive FTE

in the same period.

The workforce model should distinguish:

New Hire Date

↓

Training Period

↓

Ramp-Up Period

↓

Full Productivity

This is one of the most important improvements an organization can make to a headcount forecast.

Step 9: Apply Productivity Ramp-Up

After training, employees may gradually increase productivity.

For illustration, assume this ramp profile:

Ramp WeekProductivity
Week 120%
Week 240%
Week 360%
Week 480%
Week 5+100%

This means one employee in Ramp Week 1 contributes approximately:

0.20 effective FTE

rather than:

1.00 effective FTE

Ten employees in Ramp Week 1 contribute:

10 × 20% = 2 effective productive FTE

Gross headcount = 10.

Effective capacity = only 2 full-FTE equivalents.

That distinction can materially change a staffing forecast.

Effective FTE Formula

A simple approach is:

Effective FTE = Headcount × Productivity Factor

For example:

8 employees at 60% productivity:

8 × 60% = 4.8 effective FTE

15 employees at 80%:

15 × 80% = 12 effective FTE

20 fully productive employees:

20 × 100% = 20 effective FTE

Total:

4.8 + 12 + 20 = 36.8 effective productive FTE

Gross headcount is:

43 employees

But effective productive capacity is:

36.8 FTE

This is why headcount alone can be misleading during a hiring ramp.

Step 10: Create Workforce Cohorts

One of the best ways to forecast ramp-up is to treat employees as cohorts.

For example:

Existing Employees

Already at 100%.

February Hiring Cohort

10 employees.

March Hiring Cohort

5 employees.

April Hiring Cohort

10 employees.

Each cohort progresses through:

Training → 20% → 40% → 60% → 80% → 100%

independently.

This prevents all new hires from being treated as if they joined at the same time.

A Simple Monthly Cohort Example

Suppose:

10 employees join at the start of February.

Training = 1 week.

Then ramp:

Week 1 = 20%

Week 2 = 40%

Week 3 = 60%

Assume, for simplicity, the month contains four relevant operational weeks after accounting for training and timing.

If the cohort spends:

1 week training = 0%

1 week at 20%

1 week at 40%

1 week at 60%

Average effective productivity for the month is approximately:

(0% + 20% + 40% + 60%) ÷ 4 = 30%

So:

10 new hires × 30% = approximately 3 effective FTE

during that month.

Their gross headcount contribution is 10.

Their productive-equivalent contribution is much smaller.

The exact calculation should use actual training and working days when precision matters.

Monthly Forecasts Should Use Actual Days Where Possible

Monthly averages are useful for planning.

But if one group joins on:

2 February

and another on:

25 February

they should not contribute the same February capacity.

A more accurate model uses:

Effective Productive Days

or:

Effective Productive Hours

For example:

Monthly Effective FTE = Sum of Daily Productivity Factors ÷ Working Days

This allows training, ramp-up, joining dates and releases to be reflected more precisely.

Step 11: Include Attrition Timing

Suppose an employee leaves on the 28th day of a 30-day operating month.

Treating them as zero FTE for the entire month would understate capacity.

Similarly, someone leaving on the first working day should not be counted as a full FTE.

For detailed monthly forecasting, capacity should be adjusted based on the actual or assumed exit date.

For strategic forecasts, monthly averages may be sufficient.

The right level of precision depends on the planning horizon.

A Full Workforce Forecast Example

Suppose the operation has the following requirement:

MonthRequired Productive FTE
Jan63
Feb65
Mar71
Apr73
May75
Jun79

Now suppose estimated effective productive capacity is:

MonthEffective FTE
Jan68
Feb66
Mar68
Apr71
May76
Jun81

Then:

Staffing Variance = Effective FTE − Required FTE

MonthRequired FTEEffective FTEOver / Under
Jan6368+5
Feb6566+1
Mar7168-3
Apr7371-2
May7576+1
Jun7981+2

This immediately shows the problem.

The organization may have enough capacity overall by June.

But it is projected to be understaffed in:

March and April

That matters because hiring decisions need to be taken before the shortage appears.

Try this with your own workforce plan

You can model the same calculation using your own monthly volume, backlog, working days, AHT or CPH, current headcount, attrition, hiring, training and ramp-up assumptions in the free Praevexa Workforce Planner.

The planner shows your month-by-month required HC, effective productive HC, surplus or deficit, backlog trend and SLA risk.

Open the Free Workforce Planner

Link Open the Free Workforce Planner to:

https://www.praevexa.com/WorkforcePlanner.aspx

Hiring Lead Time Matters

Suppose recruiting takes:

4 weeks

Training takes:

1 week

Ramp-up takes:

4 weeks

The total time before a new hire reaches full productivity could be approximately:

9 weeks

If management waits until March to identify a March shortage, it is already too late.

A good workforce forecast identifies the shortage early enough for the hiring pipeline to respond.

The planning sequence becomes:

Future FTE Gap

↓

Hiring Lead Time

↓

Training

↓

Ramp

↓

Required Joining Date

This is much stronger than reacting when backlog starts increasing.

Reverse-Calculate the Hiring Requirement

Suppose:

Required effective FTE in June = 100

Forecast effective FTE without hiring = 90

Gap:

10 productive FTE

But suppose new hires are expected to contribute only:

50% effective productivity on average during June

Then hiring only 10 people will not close the gap.

Required new-hire headcount:

10 ÷ 50% = 20 hires

This demonstrates why hiring plans should be based on effective capacity, not simply one hire = one FTE.

Step 12: Forecast Attrition on New Hires Too

A long-range forecast should recognize that attrition can affect both existing employees and new hires.

For example:

Opening HC = 100

Annualized or monthly attrition assumptions may reduce that population over time.

New-hire cohorts can also experience attrition.

A sophisticated model may use different rates for:

  • Tenured employees
  • New hires
  • Different locations
  • Different roles

However, avoid excessive complexity unless the historical data supports those distinctions.

A simple, transparent assumption is often better than a complicated model with weak evidence.

Step 13: Consider Skill-Based Capacity

Suppose total required FTE is:

80

and available effective FTE is:

82

The operation appears:

+2 FTE overstaffed

But Worktype X requires:

20 skilled FTE

and only:

14 are available

The operation has:

-6 skilled FTE

for that Worktype.

Total FTE therefore hides a critical capacity problem.

A better forecast may calculate capacity by:

Department

Queue

Worktype

or:

Skill Group

This is particularly important in transaction-processing environments.

Example of Skill-Level Forecasting

Suppose:

SkillRequired FTEAvailable Effective FTEGap
General Processing4044+4
Complex Claims1813-5
Corrections1011+1
Escalations54-1

Total:

Required = 73

Available = 72

Overall gap:

-1

But the real operational issue is:

Complex Claims = -5 FTE

Management may need cross-training rather than simply hiring five general processors.

Cross-Training Can Be a Capacity Lever

Hiring is not the only way to solve a capacity shortage.

Suppose:

General Processing = +6 FTE

Complex Work = -4 FTE

If appropriate employees can be trained for the complex process, cross-training may reduce the need for external hiring.

A useful workforce forecast can therefore include:

Hiring

Cross-Training

Transfers

Releases

Ramp-Up

rather than treating hiring as the only workforce lever.

Step 14: Include Productivity Changes

Required FTE does not depend only on volume.

It also depends on processing efficiency.

Suppose:

Volume = 60,000 cases

Productive hours per FTE = 154 per month

At:

5 CPH

monthly capacity per FTE:

154 × 5 = 770 cases

Required FTE:

60,000 ÷ 770 = 77.9

Now suppose CPH improves to:

5.5

Capacity per FTE:

154 × 5.5 = 847 cases

Required FTE:

60,000 ÷ 847 = 70.8

That difference is:

7.1 productive FTE

A realistic productivity improvement can therefore materially change the hiring requirement.

But productivity improvements should not be assumed without evidence.

Do Not Build a Staffing Plan on Aspirational Productivity Alone

Suppose:

Current stable CPH = 4.5

Target = 6

If the workforce plan assumes everyone will achieve 6 next month, required FTE will be significantly understated.

A better model might use:

Base Scenario

Historical stable performance.

Improvement Scenario

Realistic expected improvement.

Target Scenario

Full target achievement.

This allows management to see the staffing consequences if productivity improvements arrive later than expected.

Step 15: Include Process Automation Carefully

Automation can reduce workload or AHT.

But planned automation should not automatically be treated as guaranteed capacity savings from the first day.

Suppose an automation is expected to reduce manual workload by:

20%

and go live in July.

A workforce forecast should consider:

  • Go-live date
  • Adoption
  • Stabilization
  • Eligible workload
  • Failure / exception rate
  • Gradual benefit realization

For example:

July impact = 25% of expected benefit

August = 50%

September = 75%

October>

This is more realistic than applying the entire saving on the implementation date.

Step 16: Model Volume Growth

Suppose baseline monthly volume is:

50,000

Expected monthly growth is:

3%

Then:

February:

50,000 × 1.03 = 51,500

March:

51,500 × 1.03 = 53,045

April:

53,045 × 1.03 ≈ 54,636

The formula is:

Future Volume = Current Volume × (1 + Growth Rate)

For longer-term forecasts, management should consider whether compounded growth is realistic or whether seasonal and business-driver models are more appropriate.

Use Business Drivers Where Possible

A stronger volume forecast may use the driver that actually creates demand.

For example:

Claims Volume = Members × Claims per Member

Applications = Customers × Applications per Customer

Service Requests = Active Accounts × Request Rate

This can be more useful than simply applying a historical percentage when the business has a measurable demand driver.

Step 17: Include Seasonality

Some operations have predictable peaks.

For example:

January = 90% of average demand

February = 95%

March = 105%

April = 110%

A simple annual average would hide those monthly differences.

Workforce forecasting should therefore include seasonal demand where historical evidence supports it.

The same annual volume can produce very different monthly staffing requirements depending on its distribution.

Step 18: Include Backlog Burn-Down Strategy

Suppose backlog is:

12,000

Management wants to eliminate it over:

6 months

A simple average additional requirement is:

12,000 ÷ 6 = 2,000 additional cases per month

If one productive FTE can process:

800 cases per month

additional productive FTE required:

2,000 ÷ 800 = 2.5 FTE

This capacity needs to be added to the incoming-demand requirement.

If management changes the burn-down period to three months:

12,000 ÷ 3 = 4,000 cases

Additional FTE:

4,000 ÷ 800 = 5 FTE

The deadline for backlog reduction directly affects staffing requirements.

Step 19: Calculate Effective FTE by Month

A workforce-planning model should eventually calculate:

Effective FTE = Steady-State FTE + Ramp-Adjusted New Hires − Capacity Lost to Releases / Attrition

For more detailed models, it can also adjust for:

  • Leave
  • Training
  • Planned shrinkage
  • Part-time allocation
  • Skill limitations

The important thing is to define each adjustment once and avoid double counting.

Do Not Double-Count Shrinkage

Suppose the capacity per FTE assumption already uses:

7 productive hours per day

after removing expected meetings and breaks.

If you then deduct those same meetings and breaks through a separate shrinkage factor, capacity is reduced twice.

Similarly, if employee leave has already been removed from available FTE, do not automatically deduct the same leave again from productive hours.

A workforce model should contain a clear assumption dictionary.

A Useful Assumption Dictionary

For each major input, document:

Metric

Definition

Value

Source

Owner

Last Updated

For example:

AssumptionValueDefinition
Productive Hours / Day7.0Expected processing hours after defined non-production time
CPH5.0Completed eligible cases per productive hour
Training Period1 weekNo steady-state production
Ramp Week 120%Relative to steady-state productivity
Attrition2% monthlyPlanning assumption based on defined employee population

This reduces disagreements when managers review the forecast.

Step 20: Calculate Over / Under Staffing

The key workforce metric is:

FTE Gap = Effective FTE − Required FTE

If:

Effective FTE = 68

Required FTE = 72

Then:

68 − 72 = -4 FTE

The operation is approximately:

4 productive FTE understaffed

If:

Effective FTE = 76

Required FTE = 72

Then:

+4 FTE

The operation has approximately four effective FTE above the modelled requirement.

Translate the Gap into Volume

Suppose one productive FTE provides:

800 cases per month

A shortage of:

4 FTE

represents:

4 × 800 = 3,200 cases per month

of estimated capacity shortfall.

That number may be more meaningful for operations managers than simply reporting:

-4 FTE

The expected impact might be:

Incoming requirement = 60,000

Available capacity = 56,800

Capacity gap = 3,200

If unresolved, backlog may increase by approximately that amount, subject to actual demand and performance.

Step 21: Create Multiple Forecast Scenarios

A workforce forecast should not pretend the future is certain.

Useful scenarios include:

Base Case

Expected volume, historical productivity and planned hiring.

High-Volume Case

Demand exceeds forecast.

Attrition Risk Case

More employees leave than expected.

Hiring Delay Case

New hires join one month late.

Productivity Improvement Case

CPH improves after process changes.

For example:

ScenarioRequired FTEEffective FTEGap
Base7574-1
High Volume8274-8
Hiring Delay7568-7
Productivity Improvement6974+5

This gives management a range of possible outcomes.

Hiring Delays Can Be More Important Than Hiring Volume

Suppose 20 hires are planned for March.

If they join in March as expected, capacity may recover by May.

If hiring slips to April, the whole capacity curve moves.

The organization may experience:

March shortage

April shortage

May shortage

even though the total number of people eventually hired remains unchanged.

Workforce forecasts should therefore track:

Joining Month

not simply:

Annual Hiring Total

Forecast Hiring as a Pipeline

For critical workforce plans, management may track:

Requirement

↓

Approved Requisitions

↓

Candidates

↓

Offers

↓

Expected Joiners

↓

Actual Joiners

↓

Training

↓

Ramp

↓

Productive FTE

This provides a much stronger picture than saying:

“We are hiring 30 people.”

Thirty open positions do not equal thirty future productive FTE.

Attrition Can Create a Hidden Replacement Requirement

Suppose an operation requires:

100 productive FTE

and starts the year with:

100

Expected annual attrition = 15%

Even if volume remains completely flat, hiring may still be needed just to replace departures.

A workforce plan should therefore separate:

Growth Hiring

from:

Replacement Hiring

For example:

Growth requirement = +10

Expected attrition replacement = +15

Total hiring requirement:

25 employees, before adjusting for hiring success, timing or ramp.

Gross Hiring Requirement Can Be Larger Than the FTE Gap

Suppose the operation needs:

10 additional productive FTE

But expected hiring realization is:

80%

and expected early attrition is also material.

The number of offers or requisitions required may exceed 10.

The exact adjustment should be based on the organization's historical recruiting funnel rather than arbitrary assumptions.

This illustrates why:

FTE Gap

Hiring Requirement

and:

Recruiting Requirement

are related but not identical.

Step 22: Include Releases Carefully

Suppose automation or process change is expected to reduce required FTE later in the year.

Management may forecast releases.

But releasing employees before the new capacity assumption is proven can create service risk.

A safer model may distinguish:

Expected Productivity Benefit

from:

Confirmed Benefit

and:

Release Eligible Capacity

This helps avoid staffing decisions based entirely on unvalidated future savings.

A Practical Month-by-Month Forecast

A simple model might contain:

MonthVolumeRequired FTEOpening HCHiresAttrition / ReleasesGross Closing HCEffective FTEGap
Jan50,00063700-26868+5
Feb52,0006568+10-27666+1
Mar57,0007176+5-27968-3
Apr58,0007379+10-38671-2
May60,00075860-28476+1
Jun63,00079840-28281+2

The exact figures here are illustrative.

What matters is the relationship between:

Gross Headcount

and:

Effective FTE

February has 76 employees on paper.

But effective productive capacity is only 66 FTE.

That is the insight the workforce forecast needs to reveal.

What Should a Workforce Forecast Dashboard Show?

A useful management view can include:

Demand

Forecast volume

Actual volume

Backlog target

Required output

Required Capacity

Required FTE

Required FTE by Worktype

Required productive hours

Workforce Supply

Opening HC

New hires

Attrition

Releases

Transfers

Closing HC

Readiness

Training HC

Ramp HC

Fully productive HC

Effective FTE

Gap

Required FTE

Effective FTE

Over / Under Staffing

Volume Capacity Gap

Risk

Hiring delay

Attrition risk

Skill shortage

Backlog impact

SLA exposure

This allows management to understand not only whether there is a gap, but what is causing it.

Common Headcount Forecasting Mistakes

Using gross headcount instead of effective FTE: Ramp and training are hidden.

Ignoring hiring lead time: Recruitment begins after the shortage appears.

Treating new hires as immediately productive: Capacity is overstated.

Ignoring attrition: Workforce supply is overstated.

Using one productivity assumption for every Worktype: Complexity is hidden.

Ignoring backlog reduction: Staffing covers only incoming demand.

Using aspirational targets instead of credible productivity: Required FTE is understated.

Ignoring skills: Overall capacity appears sufficient while specialist work is understaffed.

Assuming automation benefits immediately: Capacity savings appear too early.

Double-counting shrinkage: Effective capacity is understated.

Forecasting only one scenario: Management cannot see risk.

A Practical Headcount Forecasting Checklist

Before approving a workforce forecast, ask:

1. What is the monthly workload forecast?

2. Does it include backlog reduction?

3. What capacity can one fully productive FTE provide?

4. Are productivity assumptions supported by actual performance?

5. How many employees are currently fully productive?

6. What attrition is expected?

7. What planned releases or transfers are known?

8. How many employees need to be hired?

9. When must they join?

10. How long is training?

11. What is the ramp profile?

12. When do new hires reach steady-state productivity?

13. Are specific skills constrained?

14. Are productivity improvements or automation assumptions realistic?

15. What does the model show under high-volume or hiring-delay scenarios?

16. What is the resulting FTE and volume gap by month?

If these questions are answered clearly, the forecast becomes much more useful for workforce decisions.

From Headcount Forecasting to Workforce Intelligence

A basic staffing plan says:

Hire 20 people.

A better forecast says:

We need 20 hires by March.

A stronger workforce model says:

We are projected to be six productive FTE short in May. Because training and ramp require approximately five weeks after joining, the hiring cohort must arrive earlier. If hiring slips by one month, the projected capacity shortfall will increase backlog by approximately 4,800 cases.

Now management has something actionable.

The evolution is:

Volume Forecast

↓

Required Capacity

↓

Required FTE

↓

Workforce Supply

↓

Hiring / Attrition

↓

Training

↓

Ramp

↓

Effective FTE

↓

Gap

↓

Operational Impact

That is the difference between a hiring plan and a true workforce forecast.

Want to build this forecast without creating the model from scratch? The Praevexa Workforce Planner lets you combine demand, backlog, productivity, shrinkage, hiring, attrition, training, ramp-up and automation assumptions into a month-by-month staffing plan.

Build your workforce plan →

https://www.praevexa.com/WorkforcePlanner.aspx

How Praevexa's MIS Approach Supports Workforce Planning

Workforce forecasting becomes more effective when management can connect demand, productivity and workforce availability.

Praevexa's broader MIS and operations approach focuses on turning operational information into usable management insight.

Different Praevexa applications address different parts of the operating environment:

Praevexa Workforce Planner helps operations teams model required headcount, productive capacity, backlog, hiring, training, ramp-up and staffing gaps before those gaps affect service levels.

Link Praevexa Workforce Planner to:

https://www.praevexa.com/WorkforcePlanner.aspx

Praevexa CaseFlow supports case-based workload and operations visibility.

Praevexa QualityFlow supports structured quality information that can help identify rework and performance risk.

Praevexa HRMS supports employee, roster, attendance and leave information relevant to workforce availability.

These applications are separate systems, but the management concepts they address can all contribute to more informed workforce planning.

The planning question should move beyond:

“How many people should we hire?”

toward:

“When will we need productive capacity, and when must people join so that capacity is actually available?”

Related Reading

How to Calculate Workforce Capacity: From Headcount and Productive Hours to Required FTE

From Raw Data to Management Decisions: How to Build an Effective Operations MIS Dashboard

CPH, AHT, Productivity and Utilization: A Practical Guide for Operations Teams

How to Manage Backlog, Aging and SLA in Case-Based Operations

How to Calculate Attendance Rate, Absenteeism and Planned vs Actual Working Hours