Useful Laws and Theories

• Conway’s law: The structure of any system designed by an organization is isomorphic to the structure of the organization. Consciously design your system architecture and your organisation hand in hand and let them evolve together.

• Dunbar’s number: 150. The cognitive limit to the number of people with whom one can maintain stable social relationships — relationships in which an individual knows who each person is and how each person relates to every other person.

• Cynefin: Offers five decision-making contexts or “domains” — clear, complicated, complex, chaotic, and confusion — to help people identify how they perceive situations and make sense of behavior.

• Jobs to Be Done Theory: A theory that helps innovators understand how and why people make decisions.

• Parkinson’s law: Work expands so as to fill the time available for its completion. Use shorter sprints, cycles, meetings, and timeboxes.

• Parkinson’s law of triviality: The time spent on any agenda item is inversely proportional to the sum of money involved.

• Theory of Constraints: A chain is no stronger than its weakest link.

  1. Identify the system constraint
  2. Exploit the system’s constraint
  3. Subordinate everything else to the above decision
  4. Elevate the system’s constraint
  5. Repeat

• Gall’s Law: A complex system that works is invariably found to have evolved from a simple system that worked. Don't build or fix a complex system as a whole. Start simple and evolve.

• Engelbart’s law: The intrinsic rate of human performance is exponential. Start small and slow to "get better at getting better.”

• Little’s Law: Service time is the bottleneck that creates the queue.

• Strangler Fig Pattern: Wrap old code with the intent to redirect it to newer code — bonus points for Skunk Works cultural wrapping.

• Brooks’s law: Adding manpower to a late software project makes it later.

• Dunning–Kruger effect: People who are unskilled in an area wrongly believe their ability is higher than average. They don’t know what they don’t know.

• Occam’s razor: Entities must not be multiplied beyond necessity. Keep your teams as simple and small as possible.

• Pareto principle: For many phenomena, 80% of consequences stem from 20% of the causes.

• Vierordt’s law: Retrospectively, short intervals of time tend to be overestimated, and long intervals underestimated.

• Larman’s Law: Organizations are implicitly optimized to avoid changing the status quo.

• Bus factor: The "bus factor" is the minimum number of team members that have to suddenly disappear from a project before the project stalls due to lack of knowledgeable or competent personnel.