The document discusses the behavioral interpretation of system-environment fit and resilience, posing questions on reasoning about, comparing, and designing resilient systems. It explores intrinsic qualities, such as a system's cybernetic class, and extrinsic qualities influenced by environmental dynamics. Ultimately, it presents a framework for evaluating resilience through quality metrics and applications in optimizing system performance.

1. On the
Behavioral Interpretation of
System-Environment Fit
and Auto-Resilience
Vincenzo De Florio
MOSAIC research group
University of Antwerp & iMinds

2. RATIONALE: THREE MAIN Q’S
• How can we reason about a
system’s resilience?
• How can we tell for any two
systems which one is more
resilient?
• How can we design systems that
are optimally resilient?
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3. APPROACH
• Let us first consider a system’s
intrinsic qualities
• Quality = GST class
• Wiener’s classification: behavioral
classes
– Passive, Random, Purposeful;
Teleologic (reactive), Predictive
(proactive) behaviors 3

4. APPROACH
• Let us introduce a partial order among
the behavioral classes:
• Passive < Random <
Purposeful < Reactive <
Proactive1 < … < ProactiveN
• 1,…,N: degree of openness
• Classes: 1≤i≤N
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5. INTRINSIC QUALITY
• IQ = the behavioral classes of the
system organs responsible for resilience
– Monitoring, Analysis, Planning,
Enacting, KW processing
• Behaviors of organs (M,A,P,E,K) =
A system’s cybernetic class
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6. INTRINSIC QUALITY
• We characterize any resilient system
by its cybernetic class
1. Redundant Data Structures:
2. Adaptive N-version Programming:
• In this case IQ(1.) < IQ(2.) 6

7. INTRINSIC QUALITY
• Is IQ enough to characterize resilience?
• If I have two systems, a and b, such that
IQ(a) < IQ(b), does this imply that b is
more resilient than a ?
• Not exactly
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8. EXTRINSIC QUALITY
• Systemic features of Man are more
sophisticated than Dog’s; but what if
threat comes with, e.g., ultrasonic noise?
• Canary+Miner ≈ Miner < Miners; but
what if threat is, e.g., toxic gas in a mine?
• “What if” is the contingence
• “What if” is the environment
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9. ENVIRONMENT
 a dynamic system we interact with
• More or less predictable!
– the result of the actions of
• a human being (a “user”)
• a software component
•A cyberphysical thing
• EMI source
•…etc… 9

10. ENVIRONMENT
 Assumption: the evolution of an
environment can be expressed as a
set of behaviors
• Env  dynamic variation of a number of
“firing context figures”
• Behavioral ecoregion = “area defined by
its behavioral conditions”
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11. EXAMPLE
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• A: system, B: ecoregion
• Here A can perceive possible changes
• Here A can
perceive
impossible
changes
• Here, disaster
In general, B is B(t) !

12. ENVIRONMENTAL DYNAMICS
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13. QUALITY METRICS
• We can then define two extrinsic quality
metrics
1. System supply: how “distant” are the
system and the environmental
behaviors
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14. QUALITY METRICS
2. System-environment fit: how the system
and the environmental behavior “match”
– A measure of the adequacy of the
resilience infrastructure
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15. -1
-∞
0 2 3 0
1 0.33333 0.25 1
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5
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1
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: environmental behavior
: system behavior
: environment
: system
(t)
(t)
EXAMPLE

16. AUTO-RESILIENT BEHAVIORS!
• behaviors tracking not merely context
figures but also supply & SEF!
• Behaviors speculating and extrapolating
on future resilience requirements!
• Possibly including the social dimension!
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17. APPLICATIONS
• Redundant data structures
– Optimal amount of
redundancy
• Adaptive NVP
– Optimal amount /
selection of replicas
• LittleSister framework
– Optimization of energy,
safety, performance 17

18. CONCLUSIONS
• How can we reason about a system’s
resilience? IQ+EQ
• How can we tell for any two systems
which one is more resilient?
IQ+EQ (to some extent!)
• How can we design systems that are
optimally resilient? Auto-resilience
Computational antifragility 18

19. CONCLUSIONS
• Leibniz’s lesson (cf. Session L.2)!
Intrinsic and extrinsic qualities!
–Intrinsic: systemic & (mostly)
immutable
–Extrinsic: contingent, env-
specific, dynamic
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20. Thank you very much!
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ERACLIOS
BLOG
Computational
Antifragility