Power BI · Lesson 6 of 7

Building reports & dashboards

Choosing visuals, KPI cards, slicers, drill-down, tooltips and good report design.

A report should answer its audience's questions in seconds. A layout that works for most business reports:

Top row — KPI cards: Total Sales, Orders, Avg Order, YoY Growth %.
Middle — trend over time (line chart) and breakdown by category or region (bar chart).
Bottom — a detail table or matrix for people who need the numbers.
Slicers — Date range, Region, Category, placed consistently.

Choosing visuals

Comparison → bar or column · Trend → line · Part of a whole → stacked bar (pie only with 2–4 slices) · Relationship → scatter · Single number → card.
Add drill-down (Year → Month → Day) and tooltips for detail without clutter.
Use few colours, highlight what matters, and label everything clearly.

Sample data & steps

Power BI Desktop (free, Windows)

Report page: "Sales overview — FY 2026-27"

┌──────────────┬──────────────┬──────────────┬──────────────┐
│ Total Sales  │ Orders       │ Avg Order    │ YoY Growth % │   ← Card visuals
│ ₹ 18.3 L     │ 412          │ ₹ 4,442      │ ▲ 12.3%      │
└──────────────┴──────────────┴──────────────┴──────────────┘
┌──────────────────────────────┬─────────────────────────────┐
│ Line: Total Sales by Month   │ Bar: Total Sales by Region  │
│ (Sales LY as second line)    │ (sorted high → low)         │
└──────────────────────────────┴─────────────────────────────┘
┌────────────────────────────────────────────────────────────┐
│ Matrix: Category → Product | Qty | Total Sales | % of Total│
└────────────────────────────────────────────────────────────┘
Slicers (left panel): Date range · Region · Category

Result

Clicking "Kochi" in the region bar chart cross-filters the
cards, the line chart and the matrix to Kochi only.

Drilling down on the line chart: 2026 → Oct → daily sales for October.

Download Power BI Desktop free from Microsoft (Windows). Re-create the small sample tables in Excel, load them, and follow the steps. Data is fictional.

Key points

Lead with KPI cards, then trends, then detail.
Match the visual to the question: bar, line, card, matrix.
Slicers and cross-filtering make reports interactive.
Keep colours few and labels clear.

Quick check

Which visual is best for showing sales trend across 12 months?

Pie chart Line chart Card Gauge

Practice task

Build a one-page sales report with four KPI cards, a monthly trend line with last year's line, a sorted bar chart by region and a Date slicer, then ask a friend what they learn from it in 10 seconds.

Interview corner

How do you design an effective dashboard?

Start from the audience's key questions, put the main KPIs at the top, show trends and breakdowns next, keep detail tables at the bottom, use consistent slicers and colours, avoid clutter and make sure the numbers reconcile with the source.

What is drill-down versus drill-through?

Drill-down moves down a hierarchy inside the same visual (Year → Month → Day). Drill-through jumps to a separate detail page filtered to the item you right-clicked, such as one customer's full history.