Observations and behaviors related to the evolution of software that Lehman and his colleagues identified are known as Lehman's laws of software evolution. There are eight laws:
- Law I: Continuing change
- Law II: Increasing complexity
- Law III: Self-regulation
- Law IV: Conservation of organizational stability
- Law V: Conservation of familiarity
- Law VI: Continuing growth
- Law VII: Declining quality
- Law VIII: Feedback system
Let's look at each law in more detail.