I used to work for a company that did engineering & design work for Pemex.
A 2 year project would typically take 5~10 years to complete. We would only do work when paid in advance. Each discipline was given clear limits of the hours that could be charged this time around. We were expected to end those hours with it in shape to put it back on the shelf. It might start again in a month or 2 years. Rarely could you have the same team members start and finish their project. It would cost at least twice as much as well due to this inefficiency.
Around 30 years ago, we did a large order of parts for a few compressor rebuilds for PEMEX.
Piston and Rider rings, pressure packing and wiper ring sets, valve replacement parts, etc.
We didn't get anything up front, but we asked for 50% before they left our facility.
They sat there for a long time.
They finally paid the 50%, so we shipped the parts, but we never received the balance.
