Industry

Simulation for Aerospace & Defense
Low Volume, Long Horizon, Constrained by Resources

Aerospace and defense production is the opposite of a bottling line: units are few, cycles are long, and the thing in short supply is rarely machine capacity. It is fixtures, bays, cranes, transport, qualified people. Throughput is decided by how those resources are shared over months and years — which is a scheduling and contention problem, not a rate problem.

Who has used it

Boeing · Lockheed Martin · Raytheon · NASA · Electric Boat · SAIC · Los Alamos National Laboratory · Sandia National Laboratories · Westinghouse Savannah River · United States Marine Corps

How many fixtures buy how many rockets?

Delta IV launch vehicles are shipped to Cape Canaveral in parts and assembled near the launch site. Assembly needs specialized fixtures, each one expensive and each one occupied for a long time by a single vehicle. Buy too few and vehicles queue for a fixture; buy too many and capital sits idle between launches.

Boeing used a model to assess exactly that tradeoff — the number of specialized assembly fixtures against the throughput of assembled rockets.

Structurally this is the buffer question in different clothing. A fixture is a resource that decouples one stage from the next, its cost is capital, and the right number depends on variability rather than on averages. The arithmetic that sizes a surge tank in a chemical plant sizes an assembly fixture at a launch site.

The method is cited in the field

In 2010, Steven E. Saylor and James K. Dailey of Boeing Research & Technology presented BALANCE — the Advanced Logistics Analysis Capabilities Environment — at the Winter Simulation Conference. It builds on the non-item-based approach, citing Phelps, Parsons and Siprelle (2002).

That is a different kind of evidence from a testimonial. A major aerospace research organization built its own logistics analysis capability on this modeling approach and said so at the field’s flagship conference.

Long horizons and shared resources

Programs measured in decades

Transport and storage resource planning for Department of Energy transuranic waste was assessed over a 35-year horizon. At that timescale the question stops being "can we do it" and becomes "what do we need, when, and what happens if it arrives late" — which only a model that runs a whole program quickly can answer across scenarios.

Facility maintenance as a bid input

Resource requirements for long-term facility maintenance were modeled to support contract proposals: how much crew, plant and float a multi-year service commitment actually needs, given failures that arrive unpredictably.

Contention between programs

Bays, cranes, clean rooms and qualified technicians are shared across programs that are planned independently. A schedule that works for each program alone can be infeasible for all of them together, and that only shows up when they are simulated on the same resources.

Deployment

Everything runs on the desktop. No outbound data flow, no cloud dependency, air-gap compatible — your process data never leaves your network. In this sector that is usually the first question rather than the last.

The same mechanisms, documented on other lines

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