Logistics
Cutting dispatch turnaround from hours to minutes
Client: Meridian Logistics
Challenge
<p>Meridian ran dispatch on a system built in 2013 that had grown to 400,000 lines and could only be deployed on Sundays. A single dispatch decision took an operator between forty minutes and three hours, and nobody could explain the routing logic.</p><p>They had already attempted one rewrite, which was abandoned after fourteen months without reaching production.</p>
Solution
<p>We refused to rewrite the whole system. Instead we mapped the boundaries where data flowed one way, and found that routing could be extracted behind a narrow contract.</p><p>The new routing service ran in shadow mode against live traffic for six weeks. Once its decisions matched or beat the legacy system, we cut over one region at a time.</p><h3>Sequence</h3><ul><li>Extract and document the routing contract</li><li>Shadow-run against production traffic</li><li>Region-by-region cutover with instant rollback</li><li>Decommission the legacy path</li></ul>
Results
<p>Dispatch turnaround dropped from a range of forty minutes to three hours down to a consistent few minutes. The cutover completed across all regions without a single day of downtime, and deployment moved from monthly Sunday windows to on demand.</p><p>Two years on, the same team still maintains the service.</p>