Risk Propagation Network + Failure Mode Manifestation
Author: PlanExe Team
Date: 2026-02-10
Status: Proposal
Tags: risk, propagation, failure-modes, simulation, dependencies
Pitch
Model how local risks propagate through dependencies to system-level failure, then simulate manifestation paths across many runs to surface the most likely cascades and highest-leverage interventions.
Why
Risks rarely fail in isolation. Large project failures typically emerge from interacting risks across domains (technical, procurement, financing, regulatory). A propagation model makes these interactions explicit and actionable.
Problem
- Risk registers treat items independently.
- Teams under-estimate compounding effects.
- Mitigation choices are not ranked by systemic impact.
Proposed Solution
Build a Risk Propagation Network that:
- Represents risks, tasks, and milestones as a connected graph.
- Encodes causal links and delay effects between nodes.
- Simulates cascades across the network.
- Outputs failure pathways and intervention leverage scores.
Architecture
Plan JSON
-> Risk + Dependency Extraction
-> Propagation Graph Builder
-> Cascade Simulator (Monte Carlo)
-> Failure Path Analyzer
-> Mitigation Prioritizer
Graph Model
- Nodes: risks, tasks, milestones, resources.
- Edges: causal amplification and delay links.
- Weights: probability impact, lag time, and severity multiplier.
Example edge
- Procurement delay -> schedule slippage (weight: high, lag: 2 weeks)
- Schedule slippage -> financing drawdown risk (weight: medium, lag: 1 month)
Simulation
Run multi-step simulations to reveal cascades:
- Sample risk events based on probability distributions.
- Propagate effects through graph edges.
- Track which nodes fail, when, and how often.
Outputs per run:
- failure sequence
- time-to-failure
- cost impact
Output Schema
{
"top_failure_paths": [
{
"path": ["procurement_delay", "schedule_slip", "financing_gap"],
"probability": 0.18,
"expected_loss": 4200000
}
],
"intervention_points": [
{"node": "procurement_delay", "leverage": 0.72}
]
}
Integration Points
- Feeds into Monte Carlo plan success probability engine.
- Adds a propagation-adjusted risk score to plan ranking.
- Triggers mitigation playbooks for top cascades.
Success Metrics
- Reduction in surprise compound failures.
- Increased mitigation effectiveness vs baseline risk registers.
- Improved forecast accuracy for delays and cost overruns.
Risks
- Model complexity could obscure interpretation.
- Missing edges lead to false security.
- Overfitting to historical cascades.
Future Enhancements
- Automated edge discovery from historical plans.
- Dynamic updates as execution data arrives.
- Cross-project risk propagation benchmarking.
Detailed Implementation Plan
Phase 1: Graph Construction Layer
- Define canonical node types:
-
risk_event,task,milestone,resource_constraint -
Define edge semantics:
- causal amplification
- schedule delay transfer
- cost transfer
-
confidence score per edge
-
Build graph extraction adapters from plan artifacts:
- WBS + dependencies
- risk register
- finance assumptions
Phase 2: Propagation Simulator
- At each simulation tick:
- sample active risk events
- propagate effects along outgoing edges
-
update impacted task states and milestone forecasts
-
Capture cascade traces:
- first-trigger node
- propagation chain
-
terminal failure state
-
Aggregate over 10,000 runs:
- pathway frequencies
- expected loss per pathway
- median time-to-failure
Phase 3: Mitigation Optimizer
- Score intervention points by marginal risk reduction.
- Recommend top mitigation portfolio under budget constraints.
- Re-simulate with mitigations applied to show deltas.
Suggested algorithmic approach
- Use weighted directed graph with event queue.
- Compute influence centrality to prioritize mitigation.
- Run counterfactual analysis: remove/attenuate edge and measure probability delta.
Data model additions
risk_graph_nodes(run_id, node_id, node_type, metadata)risk_graph_edges(run_id, src, dst, edge_type, weight, lag)risk_cascade_paths(run_id, path_json, probability, expected_loss)
Integration points
- Feed risk pathway penalties into ELO/selection ranking.
- Push high-risk cascade alerts into governance dashboard.
- Link mitigation actions back into planning artifacts.
Validation checklist
- Synthetic graph tests with known cascades.
- Stability tests for edge-weight perturbation.
- Human review of top-10 pathways for interpretability.
Detailed Implementation Plan (Graph Operations)
Graph Build Pipeline
- Extract nodes from tasks, risks, resources.
- Infer edges from dependencies and causal templates.
- Score edge confidence and impact weight.
Runtime
- Run cascade simulation alongside baseline Monte Carlo.
- Persist top failure chains and intervention candidates.
Mitigation Planner
- Compute marginal risk reduction for each intervention.
- Recommend portfolio under mitigation budget constraint.
Governance
- Require review for interventions with high operational disruption.