Kent Beck’s 2016 3X model (Explore, Expand, Extract) is essentially a different way of expressing Theodore Levitt’s 1965 product life cycle (Market Development, Growth, Maturity, Decline).
- Market Development → Explore
- Growth → Expand
- Maturity → Extract
- Decline → ?
For the missing X for Decline, I propose “Exit”.
In other words, the 3X model becomes 4X:
