Tomago Aluminium had been running one of their key production systems on an aging AlphaServer for the past eight years. While the software running on the OpenVMS-based system was a good functional fit, the age and reliability of the platform was a cause for concern. For Tomago, the challenge was to find a way of upgrading and modernizing their computer hardware, while avoiding the significant costs associated with migrating to a new platform and rewriting their applications. An emulator package, which would theoretically allow the existing software to be housed on a modern Windows system, was an obvious alternative, but they worried that the emulator software might fail to perfectly replicate the legacy AXP system, which was critical for the ongoing productivity of the entire plant. An exact fit was an essential requirement.