Brownfield tie-ins: how do you get from scan to AVEVA, S3D or CADMATIC?

Plant work has its own problems: dense pipework, P&IDs that don't match the field, strict tie-in tolerances, and plant design software that doesn't read every format.

How does your team go from a scan to something the piping designers can use? Do you model in Revit, Plant 3D or the plant software directly? Which formats survive the trip? How do you check tie-in points against the scan?