Definition of Percentage Completion (30%-60%-90%)

Hello, colleagues!
I'm  tried to looking for "30%-60%-90%" definitions for oil/gas construction models and the only I had googled is http://www.red-bag.com/en/design-guides/218-bn-dg-c12-checking-a-3d-pds-piping-model-and-definition-of-percentage-completion.html
Does anybody here knows this kind of definitions for piping construction?

30% pipe routed
60% pipe fully routed (all items in complete with hold items) with support locations
90% pipe fully routed (all items in no more hold items) with final supports
This is what I have seen and sometimes 45% was used also.

Thank you, yar_nl! Have you developed internal firm rules for such tasks?

Not really. I have seen this being used at company I have worked for. Still see:
http://books.google.de/books?id=BDukAwAAQBAJ&pg=PA69&lpg=PA69&dq=30+piping+model+review&source=bl&ots=eBt9qdvivG&sig=2x_gbVM56W3hzDuwwC06dJ6hJD0&hl=nl&sa=X&ei=kinNU4ugCeS7ygOCv4KYAw&ved=0CG0Q6AEwCA#v=onepage&q=30%20piping%20model%20review&f=false
for some more info. Good book btw.

Wow! It's a cool book! Thank you very much.

Just so you know that 90 % model review means that the model is almost complete but sometimes the last 10% of the job takes about 90% of the hours.....

hmm... Why? Typical reasons? Your customer change your tasks?

It is a major undertaking the 90% review and 90% model complete does not mean that the project is at 90%.

Really, model <> project (2D drawings, BOM's, ...), of course.

Thank you one more time! I will try to read this book.