Why choosing the right chart type matters in Tableau - Business Case Study

Scenario Mode

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

📋 Request: Your manager wants you to create a report that clearly shows monthly sales performance and product category distribution to help the team make better decisions.

📊 Data: You have sales data including Date, Product Category, Sales Amount, and Region for the past six months.

🎯 Deliverable: Create a Tableau dashboard with appropriate charts that show monthly sales trends and product category sales share.

Sample Data

Date	Product Category	Sales Amount	Region
2024-01-15	Electronics	1200	North
2024-01-20	Clothing	800	South
2024-02-10	Electronics	1500	North
2024-02-18	Clothing	700	East
2024-03-05	Home Goods	900	West
2024-03-15	Electronics	1300	South
2024-04-12	Clothing	1100	North
2024-04-20	Home Goods	950	East
2024-05-08	Electronics	1600	West
2024-05-22	Clothing	850	South
2024-06-10	Home Goods	1000	North
2024-06-18	Electronics	1700	East

1

Step 1: Connect the sales data to Tableau and create a new worksheet.

Import the data source with columns: Date, Product Category, Sales Amount, Region.

Expected Result

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

2

Step 2: Create a line chart to show monthly sales trends.

Drag 'Date' to Columns, right-click and select 'Month' as date part. Drag 'Sales Amount' to Rows and set aggregation to SUM.

Expected Result

Line chart shows total sales for each month from January to June.

3

Step 3: Create a pie chart to show sales distribution by product category.

Create a new worksheet. Drag 'Product Category' to Color and Label. Drag 'Sales Amount' to Angle and set aggregation to SUM. Change mark type to Pie.

Expected Result

Pie chart displays the share of total sales for each product category.

4

Step 4: Build a dashboard combining the line chart and pie chart.

Add both worksheets to a new dashboard. Arrange line chart on top and pie chart below. Add titles and legends for clarity.

Expected Result

Dashboard clearly shows monthly sales trends and product category sales share.

5

Step 5: Explain why these chart types were chosen.

Line chart is best for showing trends over time. Pie chart is good for showing parts of a whole at a glance.

Expected Result

Manager understands how the charts help in quick and clear decision making.

Final Result

Monthly Sales Trend (Line Chart)

Jan  Feb  Mar  Apr  May  Jun
|     |     |     |     |     |
*-----*-----*-----*-----*-----*

Product Category Sales Share (Pie Chart)

[Electronics: 45%] [Clothing: 30%] [Home Goods: 25%]

✓Sales increased steadily from January to June.

✓Electronics is the largest product category by sales.

✓Clothing and Home Goods have smaller but significant shares.

Bonus Challenge

Add a filter to the dashboard to allow users to select sales by Region.

Show Hint

Use Tableau's filter feature and add a Region filter to the dashboard to enable interactive selection.

Practice

1. Why is it important to choose the right chart type in Tableau?

easy

A. It increases the file size of the Tableau workbook.

B. It makes the dashboard look colorful regardless of data.

C. It helps people understand the data quickly and clearly.

D. It hides data details from the viewers.

Solution

1. Step 1: Understand the purpose of chart selection

   Choosing the right chart type helps present data in a way that is easy to understand and interpret.

2. Step 2: Evaluate the impact of wrong chart choice

   Wrong chart types can confuse viewers or hide important insights, making data harder to grasp.

3. Final Answer:

   It helps people understand the data quickly and clearly. -> Option C

4. Quick Check:

   Right chart choice = clear understanding [OK]

Hint: Pick charts that make data easy to read and compare [OK]

Common Mistakes:

• Thinking colorful charts always mean better understanding
• Believing bigger files mean better visuals
• Assuming hiding details improves clarity

2. Which of the following is the correct way to create a bar chart in Tableau?

easy

A. Drag a dimension to Columns and a measure to Rows, then select Bar chart.

B. Drag a measure to Filters and a dimension to Pages, then select Pie chart.

C. Drag a measure to Tooltip and a dimension to Color, then select Line chart.

D. Drag a dimension to Filters and a measure to Detail, then select Scatter plot.

Solution

1. Step 1: Identify correct chart creation steps

   To create a bar chart, you place a dimension on Columns and a measure on Rows, then choose Bar chart type.

2. Step 2: Check other options for correctness

   Other options mix chart types and shelf placements incorrectly for bar charts.

3. Final Answer:

   Drag a dimension to Columns and a measure to Rows, then select Bar chart. -> Option A

4. Quick Check:

   Bar chart setup = dimension Columns + measure Rows [OK]

Hint: Bar charts need dimension on Columns and measure on Rows [OK]

Common Mistakes:

• Putting measures in Filters instead of Rows or Columns
• Confusing chart types with shelf placements
• Selecting wrong chart type after placing fields

3. Given sales data by region and time, which chart type best shows sales trends over time?

medium

A. Line chart

B. Bar chart

C. Scatter plot

D. Pie chart

Solution

1. Step 1: Identify the data and question type

   We want to see how sales change over time, which is a trend analysis.

2. Step 2: Match chart type to trend visualization

   Line charts are best for showing trends over continuous time periods.

3. Final Answer:

   Line chart -> Option A

4. Quick Check:

   Trend over time = Line chart [OK]

Hint: Use line charts to show changes over time clearly [OK]

Common Mistakes:

• Using pie charts for time trends
• Choosing scatter plots without continuous axes
• Bar charts can show categories but not smooth trends

4. You created a pie chart to compare sales by product category, but viewers say it's hard to read. What is the likely problem?

medium

A. Pie charts always show data clearly regardless of categories.

B. Pie charts are not good for comparing many categories.

C. You should add more colors to the pie slices.

D. Pie charts work best with continuous data like time.

Solution

1. Step 1: Understand pie chart limitations

   Pie charts become hard to read when there are many categories because slices get too small.

2. Step 2: Evaluate other options

   Adding colors or using pie charts for continuous data is incorrect; pie charts are best for few categories.

3. Final Answer:

   Pie charts are not good for comparing many categories. -> Option B

4. Quick Check:

   Too many slices = hard pie chart [OK]

Hint: Avoid pie charts with many small slices [OK]

Common Mistakes:

• Thinking more colors improve clarity
• Using pie charts for continuous data
• Assuming pie charts always show data clearly

5. You want to show sales distribution across regions and highlight outliers. Which combination of chart types in Tableau is best?

hard

A. Use a pie chart for distribution and a line chart for outliers.

B. Use a line chart for distribution and a box plot for outliers.

C. Use a bar chart for distribution and a pie chart for outliers.

D. Use a box plot to show distribution and a scatter plot to highlight outliers.

Solution

1. Step 1: Identify chart types for distribution and outliers

   Box plots effectively show data distribution and identify outliers visually.

2. Step 2: Confirm scatter plot use for highlighting outliers

   Scatter plots can highlight individual outlier points clearly on a chart.

3. Step 3: Evaluate other options for mismatch

   Pie and line charts do not show distribution or outliers well; bar charts lack outlier focus.

4. Final Answer:

   Use a box plot to show distribution and a scatter plot to highlight outliers. -> Option D

5. Quick Check:

   Distribution + outliers = box plot + scatter plot [OK]

Hint: Box plots show spread; scatter plots highlight outliers [OK]

Common Mistakes:

• Using pie charts for distribution
• Confusing line charts with outlier detection
• Ignoring best chart for outlier visibility