FPSO Conversions from Oil Tankers

[FPSO Reseacher]

More than 60% of all FPSO conversions have either been over budget and or late
Why?
Currently conducting doctorate researching the FPSO conversion industry worldwide.
Large multi national organisations have time after time allowed this to occur and the question is Why?

The realms of project management are no different to the project management used in the building industry, the IT industry, new development and infrastructure industries but generally these other industries do not continually come in with the results as in the marine conversion industry for FPSO's.
Searching for people who have been directly involved in conversions for their input to this research, if they wish to be part of it.

Thesis is "The Critical Success Factors for the Economical Conversion of Oil Tankers to FPSOs."

What do you consider to make up the critical success factors?

Are things like "whole of life costs", lessons learned, project management fundamentals, safety case management, interface management, change and variation management and simple cost accounting, problem areas.