Guidelines for Developing a World-class Inspection Plan

Jim Fitch, Noria Corporation
Tags: maintenance and reliability

Like most business plans and strategies, an inspection plan should be built from the top down. It should begin with a clear statement of corporate goals and objectives related to asset management. This approach is addressed in ISO 55001. Another global standard currently under construction by the International Council for Machinery Lubrication (ICML), ICML 55 focuses on optimized management of lubricated assets. It is aligned to ISO 55001 guidelines as well.

A full-on inspection plan should also be a detailed and comprehensive document to ensure that key features and functional elements are not overlooked. From there, it can be abridged or streamlined for quick review by technicians and operators. The unabridged version of the plan can even serve as a rough curriculum for training and competency testing for both current and aspiring new inspectors.

A well-constructed inspection plan enhances the likelihood and magnitude of successful and sustained deployment. The discussion that follows is more about codifying the structure of an inspection plan, including the tasks and main features that should be incorporated when writing a plan.

Modern reliability and asset management programs expect documented, procedure-based work plans. This reduces the risk of variability, uncertainty and drift over time. The plan is best if it is consensus-based and continually improved. Before considering the input of stakeholders in writing the inspection plan, first get everyone on the same page through training or self-study on the fundamental elements of Inspection 2.0.

26% of lubrication professionals say enabling inspections of their in-service oil and machinery would be the most likely reason for making machine modifications at their plant, based on a recent poll at MachineryLubrication.com

Consensus-based inspection plans tap into the knowledge and experience of skilled practitioners, old-timers and others with valuable craft skills. This provides a helpful foundation related to the machine’s operating conditions, critical inspection points, reliability history and known failure modes. It also establishes buy-in or ownership among operators, mechanics, technicians and other stakeholders who will be asked to both execute and respond to the plan.

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Furthermore, a well-constructed inspection plan communicates the importance of effort and purpose. It documents that Inspection 2.0 differentiates considerably from the conventional inspection practices of the past and that these differences are necessary to achieve the optimized level of machine reliability established by the asset owner.

When writing your inspection plan, consider the following topics:

Multiple Disciplines

For many (but not all) organizations, inspections should be cross-disciplinary. They should include lubrication, mechanical maintenance, electrical, safety and operational inspections. It makes little sense to conduct one survey for lubrication followed by a similar survey for electrical systems on the same machine. If your plant has different maintenance planners for different maintenance functions (mechanical, electrical, production, etc.), inspections can easily be divided once the information has been gathered. The critical path is getting good data and all the data. The rest will fall in place accordingly.

Common Goals

Inspection should be purposeful. It should provide routine answers to important questions about the health and condition of the machine overall as well as of the individual components and the lubricant. Inspection is a vital condition monitoring method that requires unification with other companion methods. All condition monitoring activities and technologies should conform to or align with corporate goals and business objectives, particularly as they relate to asset management and machine reliability.

As mentioned, it should start at the top and become increasingly granular and prescriptive as it works down into the specific tasks of condition monitoring and inspection. For instance, if the corporate goal is to increase earnings per share, then inspection must directly and indirectly be structured toward achieving that goal. This might come from increased worker safety, lower maintenance costs, greater asset utilization (productivity) and reduced energy consumption.

Ranked Failure Modes

What are the questions that inspections are supposed to answer? There could be many, but one is always the general state of your machine’s health. Specifically, is there confirmation of health or evidence of incipient or impending failure conditions? Therefore, you need to know the types of failures to be looking for, ranked by likelihood and risk factor. You also must know which inspection tasks and methods can alert you to a failure in progress and perhaps how advanced it might be.

Next, you should understand the root causes associated with each of these ranked failure modes and how these root causes might be recognized by inspection. One root cause can be associated with multiple failure modes. To prevent the onset of failure, it’s important to catch root causes early. All known high-risk failure modes should have at least one or more methods in your inspection plan that can reliably reveal their presence.

So, when writing an inspection plan, cross-check that all inspection methods and tasks are aligned to a prominent failure mode or its root cause and that there are no high-risk failure modes that don’t have an associated inspection method or task for early detection. This will bullet-proof your inspection strategy when executed properly.

Machine Inspection Ownership: Operator or Resident Expert?

Each task or method defined by the inspection plan must be performed with seriousness of purpose. The inspector should be responsible and accountable for quality work. In some organizations, the best choice for such an inspector is the machine operator. This is the person who works near the machines and can recognize subtle differences between what is normal and abnormal. This approach is often referred to as operator-centric inspection.

In other cases, the inspector may be a specialist who works full-time in all disciplines of condition monitoring. Perhaps the inspector is the resident expert who only does inspection routes. The advantage here is the ability to have more rigorous training and continuous practice. If you combine deep inspection knowledge with a linguistic understanding of other condition monitoring technologies (e.g., oil analysis, vibration, thermography, etc.), the value and effectiveness can be tremendous. Regardless of whether the inspection plan is operator-centric or supported by a resident expert, it must clearly define responsibilities.

Inspection Points

Inspection points are physical locations on the machine that must be defined clearly in the inspection plan. These could be couplings, shaft/seal interfaces, breathers, hose connections, sight glasses, gauges, etc. Some inspection points are not visible. For instance, consider the inspection task of touching the upper inside wall of the gear case through the fill port with your fingers. The inspection is looking for moisture condensation and soft deposits. This inspection point is not visible but necessary to assess certain headspace and lubricant conditions. Another example might be the use of a probe or dipstick to reach into the machine to collect inspection data.

Some inspection points may need to be created or installed. A large, inspection-ready machine is usually accessorized with an array of inspection windows, gauges, test points, sample valves, sediment bowls, etc., which are required to fully achieve the inspection objective. Inspection readiness enables better inspection quality (effectiveness) and frequently faster inspection, too. While there may be some costs associated with inspection hardware installation by the asset owner, the benefits can often produce multiples of that cost.

Inspection Tasks and Methods

Knowing where to inspect is just the start. Next, perform the inspection (or make the observation) as designated by the inspection plan. This can be extremely simple (e.g., determining the oil level from the sight glass) or much more complex (e.g., using a laser pointer to confirm the presence of hard or soft particle contamination). If the task or method involves many steps or requires special techniques or tools, the inspection plan must reference a procedure. The procedure is a documented method of performing certain inspections and includes the steps, tools and means of data collection.

Inspector Skills, Training and Qualification

Inspection 2.0 requires qualified inspectors who possess the skills needed to perform the tasks and methods in the inspection plan. The more complex the inspection method or task, the more there is a need for a detailed inspection procedure and training by the inspector to that procedure. An inspector must qualify to perform inspections.

This means you can’t give the inspection assignment to just anyone regardless of education, work experience or responsibility. Engineers with advanced degrees don’t have the skills to meet the inspection tasks defined by Inspection 2.0. It’s like fly fishing. You can’t give a rod and a box of artificial flies to a highly educated individual and expect him or her to wade into the stream and catch trout. If this person has never fished before, no trout will be caught.

Tools Needed

Inspection must be enabled to achieve condition monitoring quality and effectiveness at its full potential. This is the essence of Inspection 2.0. As mentioned, this increasingly means modifying and accessorizing machines to inspect better and to reach new inspection points. Inspectors also need a toolbox, as would any professional or tradesperson, to function fully in their craft. Many tools or inspection aids enable inspections that otherwise could not be performed. In other cases, they might reduce the time required to complete an inspection and/or enhance the quality and effectiveness of the inspection. The inspection plan (or the referenced procedure) should list each of the tools needed. Don’t cripple inspection performance by pretending to save money scrimping on inspector tools.

Inspection Findings and Data Collection

The type of inspection data to be collected and the manner in which it will be reported should be included in the inspection plan. This can reduce the variability that could occur if, for instance, two inspectors performed the same inspections on the same inspection point using the same methods and inspection aids. It is best if data collection is uniform and has structure. This is the concept behind using a form or checklist for paper-based data collection.

Handheld electronic data collectors can show images and comparators to more precisely score an inspection result or finding. Rather than a binary yes or no response, the results may be scaled from 1-10. Each possible result on this scale is defined by a range of comparator images or a short narrative using the data collector’s software interface. This reduces individual subjectivity and provides a scalable, analog-like feature to capture and quantify the degree of changing conditions.

Numerical data collection from inspection routes can be integrated with condition monitoring software to reveal patterns of changing conditions across an array of data types on the same machine and machine condition.

Inspection Routes

Many inspection points can be compiled and arranged into a route for a given plant or job site. This is especially helpful when a specialized inspection instrument or tool is used on only a few machines or inspection points. Its use can be scheduled and a route established. For example, a portable water contamination tester (for lubricants) may only be needed on machines that are used intermittently and are near water sources. In other cases, it might not be a particular tool but rather a specific skill that only one inspector has, such as training in ultraviolet leak detection.

Most inspections are performed daily by the same inspectors or operators who are assigned to a group of machines. In these situations, routes are not needed. The inspection plan should document all the inspection routes.

Health and Safety Issues

As previously mentioned, inspection procedures should be specified for each machine inspection task or method as defined in the inspection plan. All inspection procedures should fully cover any relevant health and safety issues.

Metrics and Compliance

All areas of business and business processes require measurement and reporting. From this information, managers can make better and more informed decisions based on accurate representations of the state of their machines. This is both at a macro level (the forest) and a micro level (the trees). So too, managers need lagging indicators (what just happened) and leading indicators (what’s going to happen). Data for these metrics can come from numerous condition monitoring sources and then be filtered and streamlined for decision-makers to use. Inspection is a great source of information related to machine reliability and asset management. This is especially the case when the data quality is at the level defined by Inspection 2.0.

Finally, metrics should include compliance. Inspections often trigger work orders to remediate current problems found by inspectors. Are these getting done in a timely fashion? Compliance may also be needed to verify that all inspection routes are being completed effectively.

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About the Author

Jim Fitch, a founder and CEO of Noria Corporation, has a wealth of experience in lubrication, oil analysis, and machinery failure investigations. He has advise...