Sankey Diagrams Explained: How Global Companies Use Flow Visuals to Tell Powerful Business Stories

Annual reports are packed with numbers but the smartest companies know that how you visualize those numbers often matters more than the numbers themselves.

One visualization that quietly delivers disproportionate insight is the Sankey diagram.

From energy flows to revenue allocation, carbon emissions to cash movement, Sankey diagrams help executives and analysts answer one deceptively simple question:

“Where is everything really going?”

In this article, we’ll break down:

  • What a Sankey diagram is (in simple terms)
  • How it’s constructed
  • Why it’s uniquely powerful
  • How global companies use it in annual reports
  • What insights you can extract that tables and bar charts simply can’t

What is a Sankey Diagram?

A Sankey diagram is a flow diagram where:

  • Nodes represent categories or stages
  • Links (flows) represent movement between them
  • The width of each flow is proportional to quantity

In other words:

Thicker flow = more volume / value

Unlike traditional charts that show levels, Sankey diagrams show movement and distribution.

Why Sankey Diagrams Are So Powerful

Most charts answer:

  • How much?
  • How many?
  • How did this change over time?

Sankey diagrams answer:

  • Where did it come from?
  • Where did it go next?
  • How much was lost, retained, or transformed along the way?

They are especially effective when:

  • Inputs split into many outputs
  • Outputs originate from many inputs
  • You want to expose inefficiencies, concentration, or leakage

Anatomy of a Sankey Diagram

Let’s break it down:

1. Nodes

These are the stages or entities in the flow.

  • Revenue sources
  • Cost categories
  • Energy types
  • Regions
  • Business units

2. Flows (Links)

  • Connect one node to another
  • Width is proportional to value (money, energy, emissions, users, etc.)

3. Conservation Principle

In most Sankey diagrams:

Total input = Total output (after splits)

This makes discrepancies and losses immediately visible.

Example: Revenue & Profit Flow – NVIDIA (Annual Report Perspective)

Use case: Revenue generation → business segments → cost allocation → operating profit

Typical Sankey Structure

Inputs (Revenue Sources)

  • Gaming
  • Data Center
  • Professional Visualization
  • Automotive
  • OEM & Other

Transformation (Value Creation & Cost Absorption)

  • Compute & Networking platforms
  • Graphics & GPU platforms
  • AI software & ecosystem investments
  • R&D expenditure
  • Manufacturing & supply chain costs
  • Sales, marketing & administrative overheads

Outputs (Financial Outcomes)

  • Cost of Revenue
  • Operating Expenses
  • Operating Income (Profit)
  • Reinvestment into R&D

Key Insights

  • Data Center flows dominate profit output, not just revenue input.
  • Gaming contributes stable inflow but proportionally less to profit growth.
  • R&D absorbs a thick, consistent flow across all revenue streams, signaling long-term moat building.
  • Automotive and OEM flows remain thin, reflecting optionality rather than current scale.

Similarly, a few more examples for references –

Images credit: App Economy Insights

Sankey diagrams don’t just visualize data – they reveal truth through flow.

They help organizations move from:

  • Static reporting → dynamic understanding
  • Siloed metrics → system-level thinking
  • “What happened?” → “Where should we intervene?”

In a world drowning in dashboards, the Sankey diagram remains one of the most honest ways to show how value actually moves through a business.

Quite often, I hear these terms are being used interchangeably.

Are there any differences between dimensions, measures, metrics and KPI (Key Performance Indicator)? Yes, there are!

Let’s take a simple example to know what these terms actually mean.

If you’re the Sales Leader of a company, you would be interested to know the performance of a particular product line in a certain year. Let’s say, the sales of a particular version of Mi Mobile is registered as 250,000 units on a flash sale held online. In this case, the dimension is referred to the product type which is Mi Mobile whereas 250,000 units is the measure (aka values).

How about Metrics (aka Business Metrics) and KPI?

Business sets a target/objective every year for its product lines. The idea is to create & drive its strategies to realize the objectives throughout the year. Metric is a way to assess the performance of a particular division or at the company level. #Revenue is one of the business metrics and is assessed by comparing against its previous year, industry standards (benchmarks), competitors.

There can be multiple metrics a company can devise and track during the year. However, there has to be certain “key” metrics which the business wants to keep a tab on a frequent basis. Those key performance metrics determine the health of the organization. In the event of any way off from the objectives, the business strives hard to do a course correction on its strategies.

KPI or simply a metric is a combination of 2 or more measures.

A simple KPI can be, #Sales of Mi Mobile in 2017 against the previous year. Assume the target set by the business in 2017 to be 500,000 units in a geographical location. The business can validate and see where they can invest further to grow their sales numbers. Popular Brands like Mi which sells primarily on online eCommerce websites have now ventured into offline stores for further growth.

For the Services industry, Customer Retention Rate would be the key. After all, retaining a customer costs relatively lesser than acquiring a new customer. Companies focus on retaining the most profitable customers as they bring in the maximum value for the top-line of the business.

Your KPI should be well defined and relevant to the business. Notably, the corresponding business stakeholders should be aligned on the same as well. A good KPI will definitely add value in measuring your performance of the business as it’s quantifiable. A bad KPI might mislead you from the focus & achieving your target.

A Scorecard or a Dashboard can be used to keep a track of the KPI metrics on a daily/weekly/monthly/quarterly/yearly basis. There are tools such as Tableau Public, MS Power BI to load your visualizations and share it among the stakeholders.