Understanding interface criticality in large infrastructure projects

In July 2023, Shoal co-presented a paper based on the iRex project; a significant transport and infrastructure project to replace the current in-service InterIslander ferries between New Zealand’s North and South Island with two custom designed ferries to increase capacity, efficiency and customer experience. The project’s scope included the complete redesign of the terminals at both Picton (South Island) and Wellington (North Island) to support the much larger hybrid ferries. Shoal worked on the iRex project as part of the systems engineering team, led by John Welford of WSP.
The Interislander is a ferry service operated by New Zealand’s state-owned rail operator, KiwiRail. The journey is roughly three and a half hours from port to port and is used by pedestrians, passenger vehicles, commercial vehicles and roll on / roll off rail freight. The latter is quite uncommon for modern ferry services but plays a fundamental role for the country to transport freight between the two islands. The roll on / roll off operations is enabled by a linkspan, which is a type of drawbridge to enable moving vehicles on and off the ferry.
One of the project requirements was for the design team to follow a systems engineering approach including requirements management, interface management, RAM (Reliability, Availability & Maintainability) and HF (Human Factors). Interface management was a considered a fundamental area of work to manage and reduce risk associated with what is a complex design within an operationally complex environment with multiple modes of transport using a relatively small space.
John Welford of WSP with Shoal team members Steve Wallace and James Donovan co-authored a paper called ‘Understanding Interface Criticality in Large Infrastructure Projects’ and presented it at the 33rd Annual INCOSE International Symposium.
Read their paper: Understanding Interface Criticality in Large Infrastructure Projects – INCOSE IS23.
View their presentation: 2023 INCOSE IS Understanding the interface criticality in infrastructure projects.
Shoal has more than two decades of experience applying systems thinking to support clients with large and complex projects. For more information, contact us.