DAX Formula for Forecasting Hours

Formula Overview

The goal is to create a DAX formula that forecasts hours based on historical data. A common technique for forecasting is utilizing the FORECAST function, which predicts future values based on existing values.

DAX Formula

ForecastedHours = 
VAR LastDate = MAX('HoursTable'[Date])
VAR NextDate = EDATE(LastDate, 1)
VAR LastValue = CALCULATE(SUM('HoursTable'[Hours]), 'HoursTable'[Date] = LastDate)
VAR ForecastValue = FORECAST(NextDate, SUM('HoursTable'[Hours]), 'HoursTable'[Date])
RETURN
    IF(ISBLANK(ForecastValue), LastValue, ForecastValue)

Explanation of Components

• LastDate: This variable captures the most recent date entry in the 'HoursTable'.

• NextDate: This calculates the next date by adding one month (using EDATE) to the LastDate. Adjust the interval as necessary for your forecasting needs (e.g., days, quarters).

• LastValue: This variable sums the hours logged on the LastDate. This value serves as a fallback if the forecast cannot be computed.

• ForecastValue: This uses the FORECAST function to predict the value for the NextDate based on the existing data in 'HoursTable'. The function requires:

  • NextDate: The date for which the forecast is made.
  • SUM('HoursTable'[Hours]): The total hours, which serves as the y value for the forecast.
  • 'HoursTable'[Date]: The independent variable or the x values for the forecasting model.

• RETURN: This checks if ForecastValue is blank. If it is, it falls back to LastValue. Otherwise, it returns the ForecastValue.

Practical Example

Assume you have a table HoursTable structured as follows:

Implementation Steps:

1. Create a measure in your Power BI model using the provided DAX formula.

2. Place the measure ForecastedHours in your report to visualize the forecast for the next month.

Result Interpretation

If the recent entry in HoursTable is for April 1, 2023, with 25 hours, the measure will calculate and predict the hours worked for May 1, 2023, leveraging historical data trends.

Conclusion

This approach to forecasting allows for a dynamic and intelligent prediction based on historical trends. Leveraging DAX functions enhances accuracy and efficiency in your data analysis efforts. For further learning and expertise in DAX, consider exploring materials available on the Enterprise DNA platform. This can greatly enhance your skill set and application of forecasting models.