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ADI Thesis — Semiconductor Supply Chain Resilience

Nine fabs, two models — how shutdowns turn into backlogs.

Simulation Supply Chain Data Analysis Risk Modelling Excel Solver AnyLogic Scenario Planning
DurationMay 2025 – August 2025 (3 months)
RoleResearch Team Member (MEngSc Applied Research Project)
TeamTeam of 4 under Dr. Vincent Hargaden
IndustrySemiconductor / Supply Chain
ToolsExcel (Solver LP), AnyLogic DES, Scenario Analysis, KPI Design

What happens when a fab goes down?

When a semiconductor fabrication plant shuts down unexpectedly, managers face cascading failures: die bank inventories drain, order backlogs spike, and recovery timelines remain unclear. Existing tools offered no fast, quantitative way to test which mitigation levers — buffers, capacity reallocation, surge production — actually work, and at what cost.

This project built two decision-support tools to give managers quantitative answers.

9 fabs
modelled
3 chip types, 4 disruption scenarios

Dual-model framework

We built a dual-model framework. The first model was an Excel Solver-based linear programme that minimised total cost across 9 fabrication plants and 3 chip types. It compared two allocation modes: fixed-mix (rule-based) versus minimum-cost (Solver-optimised), enabling instant what-if scenarios for cost attribution and capacity redistribution.

The second model was an AnyLogic discrete-event simulation modelling 9 fabs, 3 product families, die bank inventories, and order fulfilment over time. It captured week-by-week backlog dynamics, inventory depletion, and recovery trajectories — the things a spreadsheet can't show you.

We ran four categories of disruption scenarios: varying shutdown durations, critical node failures, multi-fab simultaneous shutdowns, and different restart production rates. Each scenario produced quantifiable fulfilment rates, cost impacts, and recovery timelines.

The team of 4 worked collaboratively — I contributed to both models and all scenario analysis. We presented findings directly to Analog Devices operations leadership.


What the models revealed

Fulfilment (high restart)
98%
Fulfilment (low restart)
58%
Cost Saved (optimised)
~12%
Optimal Buffer
2-3 wk

Scenario Insights


What we told ADI leadership

  1. Size die bank buffers at 2-3 weeks of demand coverage — balancing holding cost against fulfilment protection.
  2. Pre-qualify backup capacity for critical nodes (Fab 3, Fab 5) with pre-negotiated supplier contracts.
  3. Plan surge production rates post-restart — higher than baseline to clear accumulated backlog.
  4. Stress-test for simultaneous multi-fab disruptions, not just longer single ones.
  5. Deploy fab-specific control towers for real-time visibility and proactive reallocation.
"I can model the problem before it becomes a crisis."
Challenge Me On This
"Which assumption worried you most — and how did you sanity-check it?"
This is the question I want you to ask me in an interview.