Why Systems Work: Resilience, Self-organisation, Hierarchy

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Session at the Sydney Limited WIP Society about resilience, self-organisation, and hierarchy in systems

Transcript of Why Systems Work: Resilience, Self-organisation, Hierarchy

Sydney Limited WIP SocietyJason Yip

j.c.yip@computer.orghttp://jchyip.blogspot.com

@jchyip

Why Systems Work:Resilience, Self-Organisation, Hierarchy

Why do systems work?

“Resilience is a measure of a system’s ability to survive and persist within a variable environment. The opposite of resilience is brittleness or rigidity.”

Resilience comes from restorative feedback loops

Meta-resilience occurs when you have feedback loops that restore other feedback loops

Meta-meta-resilience (aka “self-organising” OR “antifragility”) comes from “feedback loops that can learn, create, design, and evolve ever more complex restorative structures.”

Examples of resilient systems

There are always limits to resilience

Resilience != static or constant

The resilient status quo could have short-term oscillations, periodic outbreaks, cycles of succession, climax, and collapse

“...systems that are constant over time can be unresilient”

Static stability != resilience

Stability is easy to see; resilience is harder to see

“...people often sacrifice resilience for stability, or for productivity, or for some other more immediate recognisable system property.”

Large organisations typically lose resilience because their sense and respond systems have to travel through too many layers of delay and distortion

Discussion: How is an Agile, Lean, Kanban system resilient?

Question: Does just-in-time sacrifice resilience (aka “just-in-case”) for cost efficiency?

The capacity of a system to make its own structure more complex is called self-organisation.

Examples of self-organisation

“Like resilience, self-organisation is often sacrificed for purposes of short-term productivity and stability.”

Self organisation...

● Produces heterogeneity and unpredictability

● Likely comes up with new structures and new ways of doing things

● Requires freedom and experimentation and a certain amount of disorder

Self organisation...

... scares individuals and threatens power structures

Conway’s Game of Life

“Even complex forms of self-organisation may arise from relatively simple organising rules - or may not.”

Question: What are the organising rules that guide self-organisation with Agile, Lean, Kanban systems?

“Complex systems can evolve from simple systems only if there are stable intermediate forms. The resulting complex forms will naturally be hierarchic.”

Example of hierarchy of systems

Hierarchies...

● Give system stability● Give resilience (unless they increase

feedback delay)● Reduce the amount of information that

any part of the system has to keep track of (aka “information hiding”)

“In hierarchical systems relationships within each subsystem are denser and stronger than relationships between subsystems.”

In software programming...

Cohesion: the degree to which the elements of a module belong together

Coupling: the degree to which a module relies on other modules

“The purpose of the upper layers of the hierarchy is to serve the purposes of the lower layers.”

Question: Does anyone have any examples of hierarchy forgetting its purpose is to help subsystems do their jobs better?

“When a subsystem’s goals dominate at the expense of the total system’s goals, the resulting behavior is called suboptimisation.”

Highly functional systems need...

● Coordination toward larger system goals● Autonomy to keep subsystems flourishing,

functioning, and self-organising

Question: How does hierarchy fit in Agile, Lean, Kanban systems?

Question: Does that cover the essence of why systems work?

Overall thoughts or questions?