Guide to Optimal Maintenance & Reliability--Optimizing via Best Practices

HOME | FAQ | Books | Links

AMAZON multi-meters discounts AMAZON oscilloscope discounts

After completing this section, you will be able to understand:

• What are best practices and why do we care?

• What do best practices have to do with maintenance and reliability?

• Key Maintenance and Reliability (M&R) terms and bench mark examples In addition, you will also be able to assess your knowledge about the basics of Maintenance and Reliability by taking a short test.

1. What Is a "Best Practice"?

The notion of a best practice is not new. Frederick Taylor, the father of modern management, said nearly 100 years ago, "Among the various methods and implements used in each element of each trade, there is always one method and one implement which is quicker and better than any of the rest." In recent times, this viewpoint has come to be known as the "one best way" or "best practice." "Best practice" is an idea which asserts that there is a technique, method, or process that is more effective at delivering a desired outcome than any other technique, method, or process. The idea is that with this technique, a project or an activity such as maintenance can be completed with fewer problems and unforeseen complications. Simply, we can say that a technique, method, or process may be deemed a "best practice" when it produces superior results. A best practice is typically a documented practice used by the most respected, competitive, and profitable organizations. When implemented appropriately, it should improve performance and efficiency in a specific area. We also need to understand that "best practice" is a relative term. To some it may be a routine or a standard practice; but to others, it may be a best practice because a current practice or method is not effective in producing the desired results.

History is filled with examples of people who were unwilling to accept or adopt the industry standard as the best way to do anything. The enormous technological changes since the Industrial Revolution bear witness to this fact. For example, at one time horses were considered the best form of transportation, even after "horseless carriages" were invented.

Today, most people drive a gasoline or diesel vehicle - all improvements on the original horseless carriage. Yet concerns over oil costs, supplies, and global warming are driving the next group of transportation improvements.

In the 1968 Summer Olympics, a young athlete named Dick Fosbury revolutionized the high-jumping technique. Using an approach that became known as the Fosbury Flop, he won the gold medal by going over the bar back-first instead of head-first. Had he relied on "standard practice," as did all of his fellow competitors, he probably would not have won the event. Instead, by ignoring standard practice, he raised the performance bar - literally - for everyone. The purpose of any standard is to provide a kind of reference. Therefore, that standard must be, "what is possible?" and not, "what is somebody else doing?"

In real-world applications, a best practice is a very useful concept.

Despite the need to improve on processes as times change and things evolve, a best practice is considered by some simply to be a business buzzword used to describe the process of developing and following a standard way of doing activities that any organization can use or implement to get better results. Implementing best practices in the area of maintenance and reliability can help an organization to:

• Increase output with the same set of assets

• Reduce the need for capital replacements

• Reduce maintenance cost per unit

• Reduce total cost per unit of output

• Improve performance - cost, productivity, and safety

• Increase competitiveness

• Increase market share

A best practice tends to spread throughout an industry after success has been demonstrated. However, demonstrated best practices can be slow to implement, even within an organization. According to the American Productivity and Quality Center, the three main barriers to adoption of a best practice are a lack of:

1. Knowledge about current best practices

2. Motivation to make changes for their adoption

3. Knowledge and skills required to do so

The objective of this guide is to provide knowledge of best practices in the areas of maintenance and reliability, and to implement best practices effectively. In later sections, we will be discussing what we can do to eliminate these barriers to create a sustainable reliability culture in an organization.

2. Terminology

Asset An electronic or mechanical hardware component or device, a software product, or a manufacturing system or process.

Benchmark Process of identifying, sharing, and using knowledge and best practices. It focuses on how to improve any given business process by exploiting topnotch approaches rather than merely measuring the best performance.

Best Practices Technique, methods, or processes that are more effective at delivering a desired outcome than any other techniques, methods, or processes. These are usually documented practices used by the most respected, competitive, and profitable organizations.

Maintenance-- The act of maintaining, or the work of keeping an asset in proper operating condition.

Reliability --The probability that an asset or item will perform its intended functions for a specific period of time under stated conditions. It’s usually expressed as a percentage and calculated using Mean Time Between Failures (MTBF).

FIG. 1 Asset Performance

3. What Do Best Practices Have to Do with Maintenance and Reliability?

In any organization, assets are needed to produce products or provide services. An item or asset, as defined here, could be an electronic or mechanical hardware component or device, a software product, or a manufacturing system or process. The objective of performing better maintenance and improving reliability of assets in an organization is to ensure that the assets are available to perform required functions, when needed, in a cost-effective manner. The performance of an asset is based on three factors (see FIG. 1):

1. Inherent reliability - how it was designed?

2. Operating environment - how it will be operated?

3. Maintenance plan - how it will be maintained?

Usually assets are designed with a certain level of reliability. This designed-in (or built-in) reliability is the result of individual components' reliability and the way they are con figured. This level of reliability is called inherent reliability. We cannot change or improve the reliability of an asset after it has been installed without replacing or modifying it with better and improved components (with the exception of redesigning it).

The second factor, the operating environment of the asset, considers operating conditions under which the asset has to operate along with the operator's skills. Several studies have indicated that 40% or more failures are the result of operational errors. Organizations need to ensure that operators are appropriately educated and trained in operating these assets with out causing operational errors that lead to failures. In fact, operators should be the first line of defense in monitoring the asset's performance and any abnormal conditions, and in initiating timely corrective actions.

The third factor is a maintenance plan that defines how the asset will be maintained. The objective of a good maintenance plan is to sustain asset reliability and to improve its availability. The plan should include the necessary maintenance and service-type actions needed to detect potential failures before they lead to unscheduled downtime.

So what do best practices have to do with these principles of maintenance and reliability? Throughout the many years of the maintenance and reliability industry, good and bad practices have been identified. These good and bad practices have been briefed at international conferences, discussed in person and over the airwaves, and written in magazines, books, websites, and blogs. The best of these practices are now becoming more accepted and published throughout local, national, and international industries, becoming the benchmarks that companies seek to achieve.

Throughout this guide, we will be discussing these factors and what best practices can be used to improve asset performance.

4. Examples of Maintenance and Reliability Benchmarks

What are the best practices in the maintenance and reliability (M&R) area and how could those be implemented to get better results? M&R best practices are practices that have been demonstrated by organizations who are leaders in their industry. These companies are the quality producers with very competitive costs, usually the lowest in their industry. A few examples (by no means an exhaustive list) of maintenance and reliability best practice benchmarks along with their related typical world class values are listed in FIG. 2.


FIG. 2 Comparing Best Practices Benchmark

Best of the Best Performance Measure Best Practice Typical Benchmark World Class Maintenance Cost as a percent of RAV (RAV - Replacement Asset Value) 2-9% 2.0-3.5% Maintenance - Material Cost as a percent of RAV 1-4% 0.25-1.25% Schedule Compliance 40-90% > 90% Percent (%) Planned work 30-90% > 85% Production Breakdown Losses 2-12% 1-2% Parts Stock- out Rate 2-10% 1-2%


The first value shown in FIG. 2, Maintenance Cost as a Percentage of Replacement Asset Value (RAV), is a maintenance performance measure that is used extensively as a benchmark for evaluating best practices. We can immediately identify the cost differences between companies that are Typical and World Class or Best in Class. However, typical companies are likely to spend more to build-up their maintenance and reliability program. Then, once they have achieved a desired level of reliability and availability, they should be able to reduce the maintenance cost by continuing to apply the best practices.

We need to be very diligent in using these benchmarks for comparative purposes because definitions of these benchmarks can vary from one organization to another. It’s significantly important to ensure that the terms used by the two organizations have the same meaning. The performance measures in FIG. 2 have been included to demonstrate this.

1. Maintenance Cost as a percent of RAV: This measure is calculated as maintenance cost divided by the replacement asset value. In this benchmark, two factors must be defined in order to ensure a comparison is accurate:

a. Maintenance cost. This factor is the cost of maintenance for a plant or facility; it includes maintenance labor, maintenance materials, contractors used to perform maintenance work, capital maintenance, and the cost of all projects to replace worn out assets.

b. Replacement Asset Value (RAV). This number typically comes from the engineering or company's insurance carrier and not from accounting. It’s not the guide value considered for accounting purposes.

Instead, it’s the current replacement cost of all assets for an industrial facility. This measure should include the cost of removing old assets and the cost of installing new ones.

2. Maintenance Material Cost as a Percent of RAV: This benchmark is very similar to the previous measure and calculated simply as maintenance material cost divided by the replacement asset value. In most organizations, the material cost is easier to obtain from the Computerized Maintenance Management System (CMMS) or organization's financial system. To ensure a comparison is accurate, we must ensure that the maintenance cost includes all maintenance material purchased for all assets in a plant, including maintenance storeroom parts and material, parts and material used by contractors on maintenance, and capital maintenance work. For example, organization "A" typically has their Maintenance Material Cost as 2% of RAV and organization "B," which has applied best practices, typically has their Maintenance Material Cost as 0.5% of RAV. This comparison indicates that organization "A" is spending four times more for maintenance material when compared to organization "B." Caution: Organizations need to understand that neither maintenance cost nor maintenance material cost can be reduced in a sustainable manner without the application of best practices. Many organizations attempt to focus solely on maintenance cost reduction, but this approach is usually misdirected until they have reviewed and improved their processes, and applied best practices.

3. Schedule Compliance: This measure is the ratio of maintenance labor hours consumed for the jobs or tasks completed (which were on an approved schedule) divided by the total maintenance labor hours available during that period. Some organizations also track the number of jobs/tasks completed which were on an approved schedule versus the total jobs/tasks on a schedule.

Maintenance Schedule. The maintenance schedule identifies jobs/tasks to be completed and approved in the previous week or at least three days in advance. It should cover 100% of maintenance labor.

For example, organization "A" is typical; their schedule compliance is 40%. Organization "B" has applied best practices and has a schedule compliance of 80%. This comparison indicates that organization "B" is actually getting twice as much scheduled work out of its maintenance staff as organization "A." When schedule compliance is high, we usually find that organizations also have high uptime and asset utilization rates. There is a direct correlation between them.

4. Percent of Planned Work: This measure calculates the percent of maintenance work orders where all parts, material, specifications, procedures, tools, etc., have been defined prior to scheduling the work. This best practice is a key to long-term success of any successful maintenance organization.

For example, a typical organization "A" has a percent of planned work measured at 30% whereas organization "B" has a percent of planned work measured at 90%. This comparison indicates that the organization "B" is proactively planning three times more work and will typically have high uptime and asset utilization rate. Their maintenance cost is also low because unplanned work costs more to execute.

5. Production/Operations Breakdowns Losses: This number becomes small and insignificant as best practices are applied and become a normal way of life. One important issue which directly impacts this benchmark is that all personnel from the executive level to production operator must be responsible for the plant's assets. The organization management must support the journey to excellence in implementing best practices. Operators must see assets as something they own. The only way this transformation can occur is through education and empowerment.

6. Parts Stock-out Rate: This measure is based on the number of times a maintenance craft person visits the storeroom to get the parts needed versus when parts are supposed to be in the storeroom, but is not available in stock.

In working with many organizations over the years, we've noted that benchmarking is not an easy process, particularly when there are no standard definitions of terms to benchmark. For example, RAV (replacement asset value) may not have same meaning to Organizations A and B. Both of them may have different definitions. This problem has been a major challenge in M&R-related benchmarking initiatives. The Society for Maintenance and Reliability Professionals (SMRP) has taken the lead toward standardized maintenance and reliability terms, definitions, and metrics. The author-along with Bob Baldwin, retired editor of Maintenance Technology Magazine, and Jerry Kahn of Siemens-has also published the manual Professional's Book to Maintenance and Reliability Terminology to standardize the M&R terms.

When measuring performance against known benchmarks of best practices, we will find that all benchmarks are interconnected and interdependent. This is why an organization must have a clearly defined group of maintenance and reliability processes to implement best practices.

Tailoring a best practice to suit your needs and working environment is essential for its successful and effective implementation.

So far, we have discussed just a few examples of best practices and their benchmarks. Throughout this guide, we will be discussing practices which may be standard, good, or best depending upon where you stand in your journey for excellence in maintenance and reliability.

5. Basic Test on Maintenance and Reliability Knowledge

Many maintenance and reliability practitioners have not been successful in implementing best practices. It’s usually due to a lack of or limited understanding of the best practices or not getting adequate management support. Take the test on the following pages to assess your knowledge of M&R best practices. This test will help you understand where you stand in your reliability journey.

Once you complete the test, go to the Appendix and score yourself appropriately. Try not to guess when answering any of the questions. If you are uncertain, skip the question and review the text later; otherwise, your results may give you a false sense of how well you know "best practices" when it comes to maintenance and reliability.

1. Best Practices are practices that are defined and applied by an organization to improve their operation. These practices may or may not be proven, but results are found to be acceptable.

a. True

b. False

2. Maintainability is measured by PM schedule compliance.

a. True

b. False

3. All maintenance personnel's time should be covered by work orders.

a. True

b. False

4. Operations and Maintenance must work as a team to achieve improved OEE.

a. True

b. False

5. Best practices would indicate that 90% or more of all maintenance work is planned.

a. True

b. False

6. 100% of PM and PdM tasks should be developed using FMEA / RCM methodology.

a. True

b. False

7. Utilization of assets in a world-class facility should be about 85%.

a. True

b. False

8. 100% of maintenance personnel's (craft) time should be scheduled.

a. True

b. False

9. Time-based PMs should be less than 20% of all PMs.

a. True

b. False

10. The 10% rule of PM is applied on critical assets.

a. True

b. False 11. Most emergency work orders should be written by production/ operations.

a. True

b. False 12. It should be common practice for Operators to perform PMs.

a. True

b. False 13. The P-F interval can be applied to visual inspections.

a. True

b. False 14. Understanding of a P-F curve should help in optimizing PM frequency.

a. True

b. False 15. The best method of measuring the Reliability of an asset is by counting downtime events.

a. True

b. False 16. The primary purpose of scheduling is to coordinate maintenance jobs for greatest utilization of the maintenance resources.

a. True

b. False 17. What percentage of your assets should be ranked critical based on the risk to business?

a. Less than 20%

b. 20-50%

c. over 50% 18. Vibration monitoring can detect uniform impeller wear.

a. True

b. False 19. Understanding the known and likely causes of failures can help design a maintenance strategy for an asset to prevent or predict failure.

a. True

b. False 20. Reliability can be improved easily after a maintenance plan has been put into operation.

a. True

b. False 21. What percentage of maintenance work should be proactive?

a. 100%

b. 85% or more

c. 50% 22. MTBF is measured by operating time divided by the number of failures of an asset.

a. True

b. False 23. Maintenance cost will decrease as reliability increases.

a. True

b. False 24. The "F" on the P-F Interval indicates that equipment is still functioning.

a. True

b. False

25. A rule of thumb is that, on average, an experienced planner can plan work for how many craft people?

a. 5

b. 15

c. 25 or more 26. Which of the following is not a primary objective for implementing a Planning process?

a. Reduce reactive work

b. Prevent delays during the maintenance process

c. Mesh the production schedule and the maintenance schedule 27. The best method of measuring the reliability of an asset is by:



c. Both 28. With the exception of emergency work orders, Planning and Scheduling will benefit all maintenance work.

a. True

b. False 29. Leading KPIs predict results.

a. True

b. False 30. The 6th S in the 6 S (also called 5 S plus) process stands for safety.

a. True

b. False 31. RCM stands for:

a. Regimented Centers of Maintenance

b. Reliability Centered Maintenance

c. Reliable Centers of Maintenance (uses best practices)

32. The objective of RCM is to preserve functions.

a. True

b. False

33. An MRO storeroom shouldn't be stocking parts for emergencies.

a. True

b. False 34. The inventory turnover ratio for MRO store should be:

a. Less than 2

b. Between 4-6

c. Over 6 35. PM compliance is a _________ KPI.

a. Lagging

b. Lagging or Leading

c. Leading 36. Quality is one key component of OEE.

a. True

b. False 37. Reliability and Maintainability can only be designed in.

a. True

b. False 38. Creating a reliability culture from a reactive mode can be accomplished in a short period of time if enough resources are made avail able.

a. True

b. False 39. Karl Fischer's Coulometric Titration Method is an effective technique to determine the metallic content (in PPM) in an oil sample.

a. True

b. False 40. An IR thermography window is an effective method to satisfy NFPA 70E arc flash requirements.

a. True

b. False 41. FMEA is applicable only to assets currently in use.

a. True

b. False

42. RCM methodology can't be used effectively on new systems being designed.

a. True

b. False 43. Properly training the M&R workforce can increase asset and plant availability.

a. True

b. False 44. TPM is a type of maintenance performed by the operators.

a. True

b. False 45. Lagging KPIs are the results of a process.

a. True

b. False 46. EOQ improves the inventory turn ratio.

a. True

b. False 47. New incoming oil from the supplier is always clean and ready to be used.

a. True

b. False 48. Which phase of the asset life cycle has the highest cost?

a. Design

b. Acquisition

c. O & M 49. Most of the maintenance costs become fixed

a. After installation

b. During operations

c. During design 50. RCM provides best results when used

a. During Operation /Production

b. During Design / Development

c. After an asset has failed or keeps failing

51. How soon we can restore an asset is measured by:




d. None of the above 52. Availability is a function of:



c. Uptime

d. Uptime and downtime 53. The failure rate of a component / asset can be calculated by knowing:

a. Number of failures



d. Uptime 54. The biggest benefit of a Failure Modes and Effects Analysis occurs during:

a. Operations phase

b. Maintenance phase

c. Design phase

d. None of the above 55. PM schedule compliance should be equal or greater than 95%.

a. True

b. False

Please go to the Appendix 1 to check the best answers to these questions. If your correct answers are: 50 or more: You have an excellent M&R knowledge, but continue to learn and enhance your knowledge.

41-49: You have good M&R knowledge, but there is a potential for improvement.

40 or less: You have significant opportunities to improve.

6. Summary

A best practice is a technique or methodology that is found to be the most effective and has consistently shown to achieve superior results.

When implemented appropriately, a best practice should improve performance and efficiency in a specific area. We need to understand that best practice is a relative term. A practice may be routine or standard to some, but to others, it may be a best practice because their current practice or method is not effective in producing the desired results.

A best practice is often not what everyone else is doing, but is what is possible to achieve. It requires persuasive techniques that rely more on appeals rather than force. A best practice usually requires a change in process; therefore, it needs to be accepted by all parties/stakeholders for successful implementation.

A best practice tends to spread throughout an industry after success has been demonstrated. However, demonstrated best practices can often be slow to implement, even within an organization. According to the American Productivity and Quality Center, the three main barriers to adoption of a best practice are a lack of:

1. Knowledge about current best practices

2. Motivation to make changes for their adoption

3. Knowledge and skills required to make changes

The work force needs to have the knowledge of best practices in the area of maintenance and reliability to implement them effectively. A commitment to using the best practices in the M&R field and utilizing all the knowledge and technology at one's disposal ensures success.


  • 1 Define best practice. What are the barriers to implementing best practices?
  • 2 What are keys factors that impact the performance of plant machinery?
  • 3 Why has reliability become a competitive advantage in today's environment?
  • 4 Identify five key performance measures in the area of maintenance and reliability. Elaborate on each element of these measures. What are typical "world class benchmark values" for these performance measures?
  • 5 Define what makes a benchmark "World Class." Discuss, using specific examples.
  • 6 Define planned work and identify its benefits. What is a typical world class benchmark number?

* SMRP - Society for Maintenance & Reliability Professionals

** IMC - International Maintenance Conference

Prev. | Next

Article Index    HOME   Project Management Articles