The encyclopedia · Engineering & Operations · Operational decision · 2006–2008
USPS optimized its highway mail network, saving millions a year.
The Postal Service built HCAP, a large-scale integer-programming tool to find cost savings in its surface-transportation network, saving over $5 million a year.
United States Postal Service
the move
The Postal Service carries more than 200 billion items a year, so small inefficiencies in how mail moves by road become large sums.
USPS, IBM and Carnegie Mellon researchers built HCAP, a large-scale integer-programming decision-support tool that identifies cost-savings opportunities across the surface-transportation network.
Analysts use the model, which encodes about 15,000 business constraints per scenario, to choose routes and schedules that cut cost and consolidate highway shipments; it saved over $10 million in its first two years and millions annually.
why it works
- The mail network was too large to tune by hand
- One model can weigh routes, capacity and service together
- Integer programming found consolidation a person would miss
- Measured: millions a year, over $10 million in two years
what transfers
When a network is too large to reason about by hand, a large-scale optimization model that evaluates every routing and scheduling option can surface savings a person would miss.
what came after
HCAP became a standing decision-support tool for postal surface-transportation analysts, and the same optimization approach later spread to other USPS supply-management categories.
references
- Optimizing Highway Transportation at the United States Postal Service
- Ilog: fait faire des économies à la poste US !
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