Forecasting in Tableau - Real Business Scenario

Scenario Mode

👤 Your Role: You are a sales analyst at a retail company.

📋 Request: Your manager wants you to forecast next quarter's sales based on historical monthly sales data.

📊 Data: You have monthly sales data for the past two years, including columns for Month, Year, and Sales Amount.

🎯 Deliverable: Create a Tableau dashboard that shows historical sales trends and a forecast for the next three months.

Sample Data

Year	Month	Sales Amount
2022	January	12000
2022	February	13500
2022	March	15000
2022	April	16000
2022	May	17000
2022	June	16500
2022	July	18000
2022	August	19000
2022	September	20000
2022	October	21000
2022	November	22000
2022	December	23000
2023	January	24000
2023	February	25000
2023	March	26000
2023	April	27000
2023	May	28000
2023	June	29000
2023	July	30000
2023	August	31000
2023	September	32000
2023	October	33000
2023	November	34000
2023	December	35000

1

Step 1: Connect your Tableau workbook to the sales data source containing Year, Month, and Sales Amount columns.

Use 'Text File' or 'Excel' connection to load the data.

Expected Result

Data is loaded and visible in Tableau's Data pane.

2

Step 2: Create a calculated field to combine Year and Month into a date field for proper time series analysis.

DATE(DATEPARSE('yyyy MMMM', STR([Year]) + ' ' + [Month]))

Expected Result

A new date field representing the first day of each month is created.

3

Step 3: Drag the new date field to the Columns shelf and Sales Amount to the Rows shelf to create a line chart showing monthly sales over time.

Columns: Date field; Rows: SUM([Sales Amount])

Expected Result

A line chart showing sales trends from January 2022 to December 2023.

4

Step 4: Enable forecasting by right-clicking on the chart and selecting 'Show Forecast'.

Use Tableau's built-in forecasting feature with default settings.

Expected Result

A forecast line appears extending three months beyond December 2023.

5

Step 5: Customize the forecast to show exactly the next three months and display confidence intervals.

Forecast Options: Set forecast length to 3 months; Show 95% confidence intervals.

Expected Result

Forecast line with shaded confidence bands for January to March 2024.

6

Step 6: Add titles and labels to the dashboard for clarity, including axis titles and a descriptive dashboard title.

Add 'Monthly Sales and Forecast' as dashboard title; Label axes as 'Date' and 'Sales Amount'.

Expected Result

Dashboard is clear and easy to understand.

Final Result

Monthly Sales and Forecast

Date -->
|
|      *
|     * *
|    *   *
|   *     *
|  *       *
| *         *
|*           *
+---------------------->
  Jan22           Mar24

* = Actual Sales
- - - = Forecast with confidence bands

✓Sales have steadily increased month over month for the past two years.

✓The forecast predicts continued growth for the next three months.

✓Confidence intervals show a moderate range of uncertainty but overall positive trend.

Bonus Challenge

Create a parameter to allow the user to select the forecast length dynamically from 1 to 6 months.

Show Hint

Use Tableau's parameter feature to create an integer parameter and update the forecast length setting to use this parameter.