Reliability Assessment: A Guide to Aligning Expectations, Practices, and Performance. Daniel Daley
If my original contention is correct (that many people are fairly naïve concerning reliability) and if you are one of the naïve people, it is likely you will find some areas you feel a need to address.
A Fictional Story — What Do You Have a Right to Expect?
Individual commitment to a group effort —
that is what makes a team work, a company work,
a society work, a civilization work.
Vince Lombardi
The setting is the waiting area outside the Plant Manager’s office. Sitting alone in the waiting area is Joe, the plant’s reliability engineer. He has been asked to meet with the plant manager at 3:00 pm and to bring with him the records for the recycle compressor in the P2S unit. It is now 3:20 pm and Joe can hear the voices of several people in the Plant Manager’s office. The voices are muffled so he cannot tell whose voices they are or what is being discussed. Joe has another meeting with his team and an equipment vendor at 4:00 so he was hoping this meeting would be over on time.
The recycle compressor in the P2S plant has had a sordid reliability history. It was the single largest cause of production losses in the P2S plant. Because that plant was in a “sold-out” position, every outage resulted in lost revenue.
At 3:35 pm, the door to the Plant Manager’s office opened; the Plant Manager looked out and invited Joe into his office. Inside, Joe found his boss, the Manager of Maintenance and Reliability, the Operation Manager for the P2S unit, and the Assistant Plant Manager. The Plant Manager dragged a chair from the back of the room into the middle of the group, then returned to his place behind the desk and took his seat.
“Have a seat, Joe. We have been discussing the recycle compressor in the P2S plant,” began the Plant Manager. “As you are aware, the machine has not been meeting our expectations and we need a solution.”
The Operations Manager interjected, “Our operators do their best to keep it running, but it is just a piece of junk.”
“It was designed, purchased, and built to the same corporate standards as the rest of this plant,” pointed out the Manager of Maintenance and Reliability, “and our maintenance department was just audited by corporate and found to be among the best in the company.”
“Let’s give Joe a chance to talk — that is what he was invited here to do,” chimed in the Assistant Plant Manager, doing his best to sound like a viable candidate for the next Plant Manager’s job that opened up. “Joe, you are the reliability expert. You probably know more than the rest of us put together,” he added.
“I am sure the machine was well designed. Corporate engineering purchased the best machine for the job, our operators are working with it as well as it can be operated, and our maintenance personnel are maintaining it as well as it can be maintained,” summarized the Plant Manager, showing his pride and ownership for each of those organizations. “It’s just not performing the way we expect it should operate and we are at a loss to understand why,” he added.
“Well, I don’t think you want to hear this, but your expectations may not be consistent with the facts,” began Joe.
“I don’t follow,” said the Plant Manager. “Are you disagreeing with what the others have said here today?”
“I assembled this file in preparation for this meeting,” began Joe. “There are a variety of records that are inconsistent with what was just said.”
“Joe, there is no reason to get defensive. No one is blaming you for the poor performance,” responded the Assistant Plant Manager.
“I was not trying to be defensive; I was just trying to lay out the history that provides some insight into what our expectations should be. The file paints a rather gloomy picture for this machine.
Of course, if that is not what you want to discuss, it is up to you”, Joe said, looking at the Plant Manager.
The Plant Manager waved Joe on saying, “I think you are right. Let’s hear about what is in the file. My impression is that we have given this machine every chance for success. Prove me wrong.”
Feeling a little like the defendant in a courtroom, Joe started down through a stack of papers in the file, sequentially handing each one to the Plant Manager and explaining what it said or meant.
“First,’ Joe noted, “there is no record of concurrent design for reliability during the initial project development. Although the designers paid attention to the functionality of the system and system integrity, they did not take any formal steps to see that this machine — or any other part of the unit, for that matter — would provide any specific level of reliability or availability.”
The Assistant Plant Manager laughed and said, “You’re telling us that this machine is likely to blow up in our faces?”
Joe responded, “No I said that integrity was addressed during the design, but not reliability or availability. It won’t blow up, but it will fail at unknown intervals. Based on the design, you don’t really know what percentage of the time the machine will need to be shut down for maintenance.”
Continuing, Joe pushed another document toward the Plant Manager saying, “This is the original bid comparison. This machine was the least expensive of all the alternatives. I am familiar with two of the other more expensive alternatives. They were selected and installed at two of our other plants. Both are experiencing much higher reliability and significantly lower maintenance costs.”
The Operations Manager commented, “If we selected the most expensive choice for every component, we would never get any new plants.”
Joe responded, “The fifteen year lifecycle cost for this choice will end up costing more than twice as much as the closest alternative. And that is without considering the value of lost production. Again, a comprehensive lifecycle cost comparison was never made during the design. In other words, the cheapest choice up front is the most expensive choice over the long haul.”
By this time, the participants in the meeting other than Joe were giving each other nervous looks and were squirming in their seats.
Joe withdrew another document from the file and pushed it toward the Plant Manager, saying, “This is the record of alignment measurements completed during construction. What the records suggest is that there was an unusually high piping load on the inlet nozzle when the compressor was placed in service. The inlet piping is 24-inch diameter and the area it passes through is quite congested. Apparently re-routing the piping was viewed as too expensive. Therefore, the machine has had to deal with high nozzle stress for its entire life.”
“But that doesn’t directly cause failures,” responded the Assistant Plant Manager.
“Well, stress translates into strain, and strain translates into displacement, and displacement between stationary and rotating components results in more wear and early wear out,” explained Joe. “In other words, it is a ‘defect’ in the system.”
Pulling yet another small stack of papers from the manila folder, Joe described their content. “These reports cover a series of events that resulted in emergency shutdowns of this machine. You can see that most of them were situations when the feed drum was allowed to exceed high level. It appears that in several situations the machine ingested at least some liquid.”
The Operations Manager took the sheets from the Plant Manager’s desk, saying “Now you are trying to blame the operators. I can assure everyone here that my operators