Over the past dozen years, my involvement in large capital projects has provided abundant opportunities for observing how things went wrong. So, let me offer a few thoughts on what can undermine project execution and how to avoid these traps.
First, the most obvious culprit is project delay. Extensively stretching out a capital project or working only fitfully on it practically guarantees the people who start the project won't be around to finish it. This seems to be one of the major reasons for missteps.
Second, confusion breeds more confusion. A constructor really doesn't care about the careers of two refinery unit supervisors fighting over a flare stack. Nor do they want to manage the stream of heat tracing change-orders resulting from incomplete knowledge of steam supply and electric loading.