Creating Correct Calculation Formulas in FirstBIT Software

This manual explains how to correctly create and validate calculation formulas in FirstBIT software, following 1C calculation logic.
It is intended for HR, Payroll, Finance, and ERP users who configure salary, allowance, overtime, or commission calculations.

1. Key Principles of Formula Creation due to system logic

When creating formulas in FirstBIT software, always follow these core principles:

1. Period-based calculation
   All calculations are performed for a defined period (usually one month).

2. Proportional accrual
   Amounts must be calculated proportionally based on:

   • days worked, or

   • hours worked.

3. Consistency of units

   • Day-based parameters must be used only with days.

   • Hour-based parameters must be used only with hours.

   • Amount-based parameters must not be mixed with time units without clear proration logic.

4. Separation of norms and actuals

   • Norm values define the standard (Norm Days / Norm Hours).

   • Actual values reflect real work (Days Worked / Hours Worked).

5. No double counting
   A formula must never reduce or increase the same amount twice (e.g. by both absence days and absence hours).

2. Parameter Reference Table

3. Recommended Formula Patterns

3.1 Monthly Salary (Day-Based)

Tariff × Days Worked / Norm Days

3.2 Hourly Salary

Tariff × Hours Worked

3.3 Salary with Absence (Days)

Tariff × (Norm Days − Absence Days) / Norm Days

3.4 Salary with Absence (Hours)

Tariff × (Norm Hours − Absence Hours)

3.5 Overtime Calculation

Tariff × Overtime Hours × Overtime Coefficient

3.6 Fixed Allowance with Proration

Fixed Amount × Days Worked / Norm Days

3.7 Sales Commission

Sales Amount × Commission Rate

or

Sales Margin × Commission Rate

4. Frequent Formula Errors (and How to Avoid Them)

 Mixing Days and Hours

Incorrect:

Tariff × Hours Worked / Norm Days

Correct:
Use hours with Norm Hours, days with Norm Days.

 Using Absence Days and Absence Hours Together

This leads to double reduction.

Choose one unit only, based on how the salary is calculated.

 Using Days In Period Instead of Norm Days

This may distort salary calculations.

 Use Norm Days unless there is a documented business reason.

 Incorrect Tariff Unit

Example:

• Hourly tariff × Days Worked

 Always match tariff unit with calculation unit.

Fixed Amount Without Proration Logic

This may overpay or underpay in partial months.

 Clearly define whether the amount should be prorated.

5. How to Self-Check a Formula (Before Saving)

Use this checklist:

Step 1: Identify the Base

• Is this calculation based on days, hours, or amount?

Step 2: Check Unit Consistency

• Days → Days Worked / Norm Days

• Hours → Hours Worked / Norm Hours

Step 3: Validate Absences

• Are absences deducted only once?

• Are days/hours used correctly?

Step 4: Test Edge Cases

• Employee joined mid-month

• Employee had absences

• Employee worked overtime

Step 5: Compare Full vs Partial Month

• Full month → full tariff amount

• Partial month → proportionally reduced amount

If the result matches expectations, the formula is correct.

6. Conclusion

Correct formula creation in FirstBIT software requires:

• strict adherence to 1C calculation logic;

• consistent use of parameters;

• careful validation before use.

Following this User Guide ensures:

• accurate payroll and commission calculations;

• predictable system behavior;

• transparency for audit and reconciliation.

Thank you for being FIRSTBit customer!