How do you use the BCG matrix to decide where to invest?

One product grows rapidly and absorbs capital. Another grows slowly but generates cash. A third operates in a promising market without yet holding a strong position. Where should the company invest?

The BCG matrix was created to make this discussion visible.

How does the BCG matrix work?

The Growth Share Matrix uses two axes:

• market growth, as an indicator of attractiveness and investment needs;
• relative market share, as an indicator of competitive position against the leading competitor.

This produces four quadrants:

• Stars: high growth and high share;
• Cash cows: low growth and high share;
• Question marks: high growth and low share;
• Pets, often called dogs: low growth and low share.

The Boston Consulting Group describes the matrix as a tool for setting priorities across different businesses. The original model, popularised by Bruce Henderson in 1970, connected market position to the generation and use of cash.

How do you apply the BCG matrix?

Define the unit being analysed: product, line or business unit. Use the same market definition for every item being compared and document the source of the data.

Relative share can be calculated by comparing the unit’s market share with that of the leading competitor. Growth requires a consistent period and clearly bounded market.

Then ask:

• which activities fund the portfolio?
• which deserve investment to build a position?
• which need an experiment before receiving more capital?
• which consume resources without a credible prospect?

Limitations to remember

The model simplifies reality. High share does not guarantee margins. A low-growth market can be highly profitable. A small activity can create decisive synergies.

BCG itself has explained that in faster and less predictable conditions, the matrix needs to be adapted to less durable competitive advantages.

Use it to open a portfolio discussion rather than automate investment or divestment decisions.

How do you calculate growth and relative share?

Market growth must be calculated using a consistent scope, geography and period. Changing the definition between activities makes the comparison less meaningful. Sources must also be documented, especially where reliable public market data is unavailable.

Relative share compares the activity’s share with that of the leading competitor. A value above one indicates a stronger position, while a value below one indicates a weaker position. The formula is simple, but the estimate depends on data quality and the market definition.

Do not treat a point on the chart as mathematical truth. Show uncertainty ranges when estimates are fragile and determine whether a small variation would genuinely change the decision.

From classification to resource allocation

The original labels suggest different dynamics. Stars may require investment to sustain growth. Cash cows may generate resources. Question marks call for selective choices. Pets invite consideration of reduction, repositioning or withdrawal.

These recommendations are not automatic. A low-share activity may own strategic technology, provide access to an important customer or support other offers. A neglected cash cow can quickly lose its position. Before moving capital, consider synergies, margins, capabilities and the activity’s role within the portfolio.

The matrix works best as the start of a discussion. It asks why certain activities absorb resources, which assumptions justify new investments and which signals would bring them to an end.

When is the BCG matrix useful?

The tool makes sense when an organisation manages several products or business units and needs to compare investment requests. It is less useful for a company with one offer or when markets cannot be defined credibly.

Before applying it, verify that comparable units, sufficient evidence and a real portfolio decision exist. Otherwise, a focused financial and competitive analysis may be clearer than the matrix.

Which analyses should complement it?

Add margins, cash flows, competitive advantage, synergies, risks and required capabilities to the position on the chart. A small activity may hold technology that benefits the entire portfolio. A dominant position may depend on a market that is about to contract rapidly.

Compare scenarios as well. If growth slows or a competitor increases its share, does the decision remain valid? This check turns the matrix from a static snapshot into support for capital allocation.