- 1 Systems Thinking Primer
- 1.1 Systems Thinking
- 1.2 Principles of Systems Thinking
- 1.3 Systemic Laws
- 1.3.1 Brooke’s Law
- 1.3.2 Parkinson’s Law of Triviality
- 1.3.3 Weinberg Brooke's Law
- 1.3.4 Postel’s Law – The Robustness Principle
- 1.3.5 Conway’s Law
- 1.3.6 Parkinson’s Law
- 1.3.7 Hawthorne Effect
- 1.3.8 Campbell’s Law
- 1.3.9 Goodhart’s Law
- 1.3.10 Little’s Law
- 1.3.11 Local Optimisation
- 1.3.12 Sub-Optimisation Principle
- 1.4 Further Readings
Systems Thinking Primer
Systems thinking is a holistic approach to the belief that the component parts of a system will act differently when isolated from the system's environment or other parts of the system, (Leyla Acaroglu 2017, Medium.com).
There is a definition from Peter Senge's highly influential The Fifth Discipline Fieldbook:
"Systems thinking [is] a way of thinking about, and a language for describing and understanding, the forces and interrelationships that shape the behavior of systems. This discipline helps us to see how to change systems more effectively and to act more in tune with the natural processes of the natural and economic world."
Another quote from Peter Senge's book:
“Systems thinking is a conceptual framework, a body of knowledge and tools that has been developed over the last 50 years, to make full patterns clearer, and help see how to change them effectively.”
As a management discipline Systems Thinking concerns an understanding of a system by examining the linkages and interactions between the components that comprise the entirety of that defined system.
Thereby, a system is an entity with interrelated and interdependent parts; it is defined by its boundaries and it is more than the sum of its parts (subsystem). The boundaries of a whole system may be chosen and defined at a level suitable for the particular purpose under consideration.
Changing one part of the system affects other parts and the whole system, with predictable patterns of behavior.
Principles of Systems Thinking
System Thinking is grounded on 5 basic principles, (thwink.org)
- A feedback loop is system structure that causes an output from one node to eventually influence input to that same node.
- A feedback loop is either reinforcing or balancing.
- The behavior of all dynamics systems is generated by its feedback loops.
Therefore, the key principle:
- The important behavior of a system emerges from its key feedback loops.
- The behavior of a large complex system is generally so counterintuitive that it cannot be correctly understood without modeling the system's key feedback loops.
Related to Systems Thinking there are some very popular quotes:
"95% of variation in the performance of a system (organisation) is caused by the system itself and only 5% caused by the people."
– W. Edwards Deming
"Misconception easily turns into common sense."
– Taiichi Ohno
“In general difficulties of an organisation arise not from outside influences […] rather than what we do ourselves”
– Jay Forrester, Sloan School of Management
Besides to these quotes, there are some empirical laws concerned with Systems Thinking.
“Adding manpower to a late software project makes it later.”
– Frederick P. Brooks: The Mythical Man-Month. 1975
Parkinson’s Law of Triviality
“The human tendency to devote a great deal of time to unimportant details while crucial matters go unattended.”
– C. Northcote Parkinson
Weinberg Brooke's Law
“More software projects have gone awry from management’s taking action based on incorrect system models than for all other causes combined.”
– Gerald Weinberg, Quality Software Management: System Thinking. 1992
Postel’s Law – The Robustness Principle
“Be conservative in what you do, be liberal in what you accept from others.”
– Jon Postel, Internet pioneer
“organisations which design systems […] are constrained to produce designs which are copies of the communication structures of these organisations.”
– Mel Conway
“organisations tend to get bigger.”
“Individuals modify their behavior in response to their awareness of being observed.”
“Once a metric has been identified as a primary indicator for success, its ability to accurately measure success tends to be compromised.”
– Donald T. Campbell, American social scientist
“When a measure becomes a target, it ceases to be a good measure.”
– Charles Goodhart, British economist
“Under steady state conditions, the average number of items in a queuing system equals the average rate at which items arrive multiplied by the average time that an item spends in the system.”
– John Little
“Focusing on one property (only) may have unintended effect on the system as a whole.”
“If each subsystem, regarded separately, is made to operate with maximum efficiency, the system as a whole will not operate with utmost efficiency.”
– General Systems Theory (Lars Skyttner)
- Donald G. Reinertsen2009: The Principles of Product Development Flow. Second Generation Lean Product Development. Celeritas Publishing, 2009.
- Daniel S. Vacanti 2015: Actionable Agile Metrics for Predictability: An Introduction. Leanpub, 2015.
- Donella H. Meadows 2008: Thinking in Systems: A Primer. Chelsea Green Publishing Co, 2008.
- Peter Senge 2006: The Fifth Discipline. Crown Business, 2006.
- Peter Senge 1994: The Fifth Discipline Fieldbook: Strategies for Building a Learning organisation. Nicholas Brealey Publishing, 1994.
- Peter Kline, Bernard Saunders 1993: 10 Steps to a Learning organisation. Pfeiffer Wiley, 1993.
- Linda Booth Sweeney, Dennis Meadows 2010: The Systems Thinking Playbook. Chelsea Green Publishing Co, 2010.
- John Bicheno 2015: The Lean Games and Simulation Book. Picsie Books, 2015.
- Leyla Acaroglu 2017: Tools for Systems Thinkers: The 6 Fundamental Concepts of Systems Thinking. Medium.com, Sep 7, 2017.
: Wikipedia.org, .