Reliability Assessment: A Guide to Aligning Expectations, Practices, and Performance

By Daniel Daley

Addressing the elements of reliability using a new and creative approach for the first time in one source, this book is intended to simplify the assessment of reliability by first identifying the current expectations then assessing the current practices to determine if expectations are realistic or if they are not supported by programs and practices. It combines the most effective and efficient of those approaches into a single activity that shows managers what they have a right to expect and what they do not. Most often, this discovery comes as the result of painful failures and production losses. This unique book and the process it describes will allow the discovery of this misalignment to take place at a more convenient and less costly time. Designed to be easy to read, this resource is perfect for busy people who have little time for long and tedious texts or courses that take them away from their workplace. Reliability Engineers, Maintenance and Reliability Managers, Engineering Managers, Plant and Corporate Senior Staff and Executives looking ways to enhance performance, and Consultants who may want to enrich their portfolio by adding this tool will all benefit from the information found in this resource.

• Provides the reader with a clear description of the overall concept of Aligning Reliability Expectations.
• Contains both simple examples and the methodology needed to determine if the programs at each step during the lifecycle of a plant or system will adequately create or maintain reliability.
• Describes how to organize a Wide-Hart assessment.
• Describes how to conduct a Wide-Hart assessment.
• Describes how to communicate results of a Wide-Hart assessment.
• Describes steps in organizing for correcting weaknesses found during the Wide-Hart assessment.
• Contains the Control Document for organizing the assessment and corrective action and the Assessment form for organizing results from assessment and describing results.

• Language: English
• Publisher: Industrial Press, Inc.
• Release date: Dec 16, 2009
• ISBN: 9780831190613

Book preview

Introduction

Climate is what we expect, weather is what we get.

Mark Twain

A number of years ago, I heard someone refer to a concept called the device mentality. It was a way of describing a naïve viewpoint of complex devices. For instance, a young driver with a device mentality would view a car as simply being a steering wheel, an accelerator, and a brake. You push the accelerator to make it go. You push the brake to make it stop. And you turn the wheel to choose the direction. All other details are unimportant.

I have occasionally used this concept when describing issues related to reliability. As it turns out, people with a device mentality create a problem for people in the reliability business. They neither know nor care how their actions makes things fail. However, if it is possible to engage these individuals in caring how a thing works and what they can do to avoid causing damage, reliability will improve.

Although the most obvious example of an individual with a device mentality is a young person operating an automobile, many individuals you would expect to have a thorough understanding of reliability still remain quite naïve. Even some fairly senior managers of companies that depend on complex machinery for their source of income have a limited understanding of the things that result in high reliability and those that do the opposite.

The reason for introducing the device mentality is that the same people who view a car as little more than a steering wheel, an accelerator, and a brake also expect their vehicle to operate flawlessly with little or no maintenance forever. This same paradigm exists with people who operate complex equipment.

There is an entire spectrum of how well people understand reliability. At one extreme are folks with the device mentality who are clueless. At the other extreme are individuals who understand the subject very well. Generally speaking, if you were to create a graph showing the number of people at each point on the spectrum, it would not be a normal distribution. Most people are pretty naïve about reliability. Most people just expect things to work and not be an inconvenience to them.

As mentioned above, even individuals who regularly deal with complex systems are often poorly informed concerning what makes a system reliable and what is likely to make in unreliable. If you were to ask them to characterize their expectations concerning the reliability of their systems, they would say they expect excellent reliability. If you were to ask them again why they have those expectations, they would say that their systems were designed to the highest standards and constructed with the finest materials. Although those factors have some bearing on reliability, there are many, many other factors that are equally if not more important.

So, for the moment, if we accept the premise that many people have a naïve or distorted notion of reliability, the next question should be, so what?

Recently I read an article in the business section of the local newspaper about a bio-fuel plant filing for bankruptcy. The explanation provided by the owners was that uncontrollable outages during early operation resulted in economic losses. Apparently they blamed the problems on gremlins. More likely, the individuals who owned the plant knew little about reliability. Maybe the people who engineered and constructed the plant provided the owners with slick brochures showing people with smiling faces working in a clean, smoothly operating plant. The owners might have been provided with a tour through a smoothly operating facility. Everything they saw suggested that you simply turned the key and the plant started up and ran forever flawlessly cranking out money.

Nowhere in the process of purchasing, designing, or building the facility did anyone mention anything about reliability or what was needed to achieve it. No one mentioned:

•There are choices that can be made during the design process that will provide a more reliable configuration.

•There are choices that can be made during procurement that will provide more robust equipment.

•There are choices that can be made during construction, commissioning, and start-up that will ensure the systems start-up and operate smoothly.

•There are different ways the plant can be operated that will affect reliability.

•There are different ways to maintain the plant that will affect reliability.

•There are ways to provide routine inspection and oversight that will identify failure mechanisms at work and defects before they can cause a failure.

•There are steps that can be taken during modifications and renewal that will ensure that inherent reliability is maintained or improved.

If only someone would have told the owners about all these issues, maybe they would have made choices that would have prevented all the problems leading to the bankruptcy.

As the title of this book implies, the objective is to provide an approach to aligning yout reliability expectations. That title may be a little misleading to some. A better title might be, Developing realistic expectations for reliability or, better yet, Finding out how bad things really are. Independent of the title, at the conclusion of this book, the reader should understand:

1.What elements determine reliability

2.How to evaluate how well you are currently dealing with those elements

Rather than spending more time worrying over the most appropriate title, let’s focus on the meaning of aligning reliability expectations. Let’s begin by carefully defining the terms.

For our purposes, the definition of expectation is a level of performance that is considered reasonable or due. Although it may seem I am being overly precise, it is important to clearly separate feelings from facts. An expectation may be viewed as being reasonable or due even though the facts or tangible evidence may not support those feelings.

The term reliability is intended to go beyond the textbook definition of reliability. In this context, I am using the term reliability to embrace the concepts of reliability, availability, and maintainability.

More specifically, these terms have the following definitions:

•Reliability is the instantaneous likelihood that a system or device will fail during a specific interval of time.

•Availability is a measure of the percentage of time a system can perform its intended function.

•Maintainability is a measure of the ability to restore the full inherent reliability in a ratable period of time.

Thus, reliability is used somewhat like the term expectation. It is applied in a manner that exposes the concept that most people feel when they use the term. They typically use the term to represent a broad sense of robustness.

Finally, the dictionary definitions of the term align or aligning are to arrange in a line or to ally oneself or to take sides. In this context, the term is intended to describe the process needed to develop a thorough understanding of what is required (to achieve a specific level of performance) and what actually exists. From this knowledge, it is possible to form realistic expectations.

More specifically, this book is intended to answer the following questions:

•What is the spectrum of issues involved in determining the reliability of a system?

•Which of those issues are reasonable to trust to external controls?

•How do you control the issues that cannot be trusted to fate?

•How do you determine that an issue is out of control?

•Based on the above, what level of reliability performance should you expect?

•Where should you add focus to improve your reliability?

•How do you go about adding that focus?

Reading this book might make you comfortable with your current organization and procedures. More likely, it will make you uncomfortable with some of your procedures and lead you to question others. In the final analysis, just reading the book will do little good. In addition to reading the book, it will be necessary to do a few things:

1.Self reflection to identify your spoken and unspoken expectations for reliability.

2.Assess your current organization and procedures and how reliability-related tasks are actually being done.

3.Identify the areas where there are gaps in your current systems and how they are likely to affect reliability.

4.Compare your expectations to the results your systems are capable of providing.

When that effort is complete, you may be satisfied or you may be dissatisfied. 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.

Chapter 1

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