The product lifecycle is the four-stage model of commercial life through introduction, growth, maturity, and decline, used to inform investment, pricing, and sunset decisions. Introduction covers launch and early adoption; growth covers rapid adoption, scale, and competitive entry; maturity covers slowing growth and pricing pressure; decline covers replacement by alternatives and eventual sunset. The framework was popularized by Theodore Levitt in his 1965 Harvard Business Review article "Exploit the Product Life Cycle" and has been adapted from physical-product marketing into software product management.
The four classical stages with their typical characteristics: introduction (low sales volume, high per-unit cost, focus...