cps-resilience-roadmap

---
name: cps-resilience-roadmap
description: Resilient Cyberphysical Systems design framework based on the NSF Technology Roadmap. Addresses resilience from three sources - exogenous factors, design-reality mismatch, and engineered fragility.
version: 1.0.0
author: Research Synthesis
license: MIT
metadata:
  hermes:
    tags: [systems-engineering, cyberphysical-systems, resilience, design-patterns, cps]
    related_skills: [soft-control-multi-agent, system-resilience-design-patterns]
    source_paper: "Resilient Cyberphysical Systems and their Application Drivers: A Technology Roadmap (arXiv:2001.00090)"
    citations: 15
    workshop: "NSF-supported workshop on Grand Challenges in Resilience, Purdue, March 2019"
---

# Resilient Cyberphysical Systems (CPS) Design

A comprehensive framework for designing cyberphysical systems that are resilient-from-the-ground-up and resilient-by-reaction through progressive learning. Based on the NSF Technology Roadmap from Purdue University's workshop on Grand Challenges in Resilience.

## The Three Sources of Fragility

Resilient CPS design must address three fundamental sources of system fragility:

### 1. Exogenous Factors
External forces that impact the system:
- **Natural variations** - Environmental fluctuations, weather, load changes
- **Attack scenarios** - Cyber attacks, physical tampering, DDoS
- **Black swan events** - Rare, high-impact disruptions
- **Infrastructure failures** - Power grid outages, network failures

### 2. Design-Reality Mismatch
Gaps between engineered designs and real-world conditions:
- **Model inaccuracies** - Simplified models don't capture reality
- **Unanticipated use cases** - Edge cases not considered in design
- **Environmental changes** - System context evolves over time
- **Component degradation** - Hardware/software aging

### 3. Engineered Fragility
Inherent weaknesses in the design itself:
- **Software bugs** - Coding errors, logic flaws
- **Human-computer interaction issues** - Poor usability, operator errors
- **Complexity** - Interconnected components create emergent behaviors
- **Single points of failure** - Critical dependencies

## Resilience Design Principles

### Principle 1: Resilience-from-the-Ground-Up
Build resilience into the system architecture from initial design.

### Principle 2: Resilience-by-Reaction
Enable the system to learn and adapt through progressive learning.

### Principle 3: Defense in Depth
Multiple overlapping protection mechanisms at different layers.

## Resilience Patterns

### Pattern 1: Circuit Breaker
Prevent cascade failures by failing fast when errors exceed threshold.

### Pattern 2: Bulkhead Isolation
Contain failures to prevent system-wide impact by isolating resources.

### Pattern 3: Retry with Backoff
Transient failure recovery using exponential backoff with jitter.

### Pattern 4: Health Endpoint Monitoring
Continuous system health assessment with critical/non-critical checks.

## Application Domains

- Smart Cities (micro and macro communities)
- Smart Buildings (HVAC, access control, energy)
- Industrial IoT (manufacturing, supply chain)
- Healthcare CPS (medical devices, hospitals)
- Autonomous Vehicles (V2V, navigation, safety)

## Resilience Metrics

- Mean Time Between Failures (MTBF)
- Mean Time To Recovery (MTTR)
- Availability = MTBF / (MTBF + MTTR)
- Recovery Point Objective (RPO)
- Recovery Time Objective (RTO)

## References

1. Chaterji, S., et al. (2019). Resilient Cyberphysical Systems and their Application Drivers: A Technology Roadmap. arXiv:2001.00090.

2. NSF-supported workshop on Grand Challenges in Resilience, Purdue University, March 20-21, 2019.

## Trigger Words

- cyberphysical systems, CPS resilience, resilient design, fault tolerance, system resilience, graceful degradation, circuit breaker, bulkhead pattern, chaos engineering

## See Also

- soft-control-multi-agent
- system-resilience-design-patterns