[QUOTE=Tredici][QUOTE=Bronco_Beerslug]Managements position on refinery maintenance is that the best thing possible is to keep them running constantly. They all use the same excuse for not performing more maintenance (there is more chance for something going wrong bringing the units up and down).
Thats not completely true. Hard shut downs of units caused by a power outage or lightning strike for example are extremely hard to cope with and cause major damage - sometimes in parts of equipment seeminly unrelated.
Planned shutdowns performed by the unit specifications are simply a part of maintenance, they are designed to be brought down and up. Meeting mandated product volumes and budget restrictions are far more likely to be the reason decisions are made and lots of smokescreens like the one you've suggested being used as cover.
If done when they are supposed to be done, yes. And like you pointed out, refineries are under so much pressure to keep pumping out fuel that they often ignore recommended maintenance schedules. Another factor is money. It's extremely expensive to shut down operations for any length of time. Just like power plants all across this country that ignore recommended maintenance until the plant actually can't run any longer without being repaired.
Having personally been involved in maintenance on refineries, power plants and chemical plants, for many years, I've seen some things that just make you shake your head and walk away.