Live modernizations of automated material handling systems: Bridging the gap between design and startup using emulation

Modernization projects on mission-critical automated material-handling systems are often performed while the system and the processes it supports remain operational. A successful live-system modernization depends on a rapid, predictable startup with no unmitigated risks. This is achieved through extensive testing prior to startup, which can not be performed while the system is in service. During a project, engineers overcame the live system´s availability constraints by creating a software-based virtual system, emulating all control and feedback signals, operating speeds, constraints, and physical characteristics of the equipment. Twenty-one programmable controllers, a supervisory computer system, and four operator interface applications, all developed to operate the physical system, were connected to the model. All subsystems were brought online, and the system was run as a whole. All software, algorithm, control system, operator-interface, and factory-acceptance tests were performed in the model environment. The modernized system was brought online without disruption to any factory operations.