Define comparable units and markets
Compare businesses, offers or product-market pairs at the same level. A global brand, a local product and an experiment are not comparable portfolio units without reframing.
Growth depends on market scope and period. Relative share depends on the chosen competitor. Retain these definitions, sources and dates so the chart can be reproduced.
- Stable unit of analysis
- Documented reference market
- Common period
- Source and date
- Reference competitor
Calculate both axes transparently
Relative market share is the unit’s share divided by the selected leading competitor’s share. A value above 1 means the unit has a larger share than that competitor. Growth describes the market over the chosen period, not the product alone.
Illustrative example: A has 30% against 20%, giving 1.50. B has 15% against 30%, giving 0.50. Their market growth rates are 8% and 12%. High and low thresholds belong to the decision file and are not universal constants.
| Unit | Unit share | Competitor share | Relative share | Growth |
|---|---|---|---|---|
| A | 30% | 20% | 1.50 | 8% |
| B | 15% | 30% | 0.50 | 12% |
| C | 35% | 25% | 1.40 | 2% |
Treat quadrants as hypotheses
Stars, cash cows, question marks and dogs compress two measures. They do not directly include profitability, investment need, synergies or reversibility.
A low-growth business may fund options only if cash generation is evidenced. A low-share niche may still be profitable. Test every quadrant-led direction against economic and strategic evidence.
Connect BCG with Product Life Cycle Analysis without merging them
Product Life Cycle Analysis describes a hypothesis about how sales and profitability evolve through introduction, growth, maturity and decline. The path is neither necessarily linear nor the same for every product.
BCG measures market growth and relative share at a stated date. Life-cycle evidence may explain investment needs or maturity, but it replaces neither axis, determines no quadrant and never justifies divestment on its own.
Move from the chart to the trade-off
Retain calculations, data quality, thresholds and open questions. In the proposed journey, Grid structures the portfolio and Plot supports the BCG analysis. Data and decisions remain explicitly validated; neither workspace exchange nor allocation is assumed to be automatic.
Record whether to invest, maintain, test, divest or stop, together with amount, owner, review condition and portfolio consequences.
Frequently asked questions
Which market-growth threshold should be used?
There is no universal threshold. Choose a defensible reference for the market and horizon, then test sensitivity.
What if no reliable competitor is available?
Mark relative share as not computable and investigate. An arbitrary number would create a misleading quadrant.
Is the BCG matrix enough to allocate budget?
No. Add margins, cash needs, capacity, risk, synergies and constraints.
Full sources
- Academic empirical analysis of the BCG portfolio model, PDFComplete source available online↗
- MIT Sloan, scientific portfolio-management models, complete notesComplete source available online↗
- Persistence and limits of the BCG matrixComplete source available online↗
- Growth-share matrix caveatsComplete source available online↗
- Product Life Cycle Analysis and its stagesComplete source available online↗