13 Lean Six Sigma Principles in Machinery Lubrication: A Baker’s Dozen

Matthew Adams, Noria Corporation

Overlapping Skill Sets

There have been many times in my career when I have looked back with awe at where my path has led me. A great and often overlooked result of transitioning from one career or company to another is the opportunity to gain unique field experiences and adapt them to new practices along the way. My first occupation post-education was functioning in an industrial engineering role at an appliance manufacturing facility. In this position, I spent a fair amount of time working alongside team members to install and run-in new equipment, balance manufacturing lines, improve plant processes, as well as integrate lean and Six Sigma principles. While I have chosen to advance in my career and move outside the realm of this industry and field practice, I still carry many of these skills with me. I often practice them in the field of machinery lubrication and oil analysis today. As you begin to progress in your career and step into new roles and responsibilities, it may be worthwhile to make note of how prior experiences can benefit you in your new position.

Introduction to Lean Six Sigma

Lean Six Sigma is a methodology used to aid facilities in delivering strong client value through curtailing waste and errors while also improving quality and consistency. While lean and Six Sigma impressions have two separate identities, they often coexist during development. Facilities benefit greatly by implementing both concepts, to a certain degree, simultaneously. The lean portion of this concept concentrates on the streamlining of processes while Six Sigma concentrates on quality. Through the integration of these disciplines, sites often see an increase in profit, a decrease in costs and improved process competencies; as a result, overall customer satisfaction improves. While this proven technique is most notably used in product manufacturing, there are a multitude of industries and field disciplines that can gain efficient market advantages though lean Six Sigma implementation as well. Even within a specified niche arena such as machinery lubrication, there are numerous elements in which lean Six Sigma plays a significant role. We will take a look at 13 specific lean Six Sigma principles that can directly affect your lubrication program.

Excess Processing: Lubricant Consolidation

One fundamental principle in the implementation of lean methodology is excess processing, or the identification and reduction of excess processing. Excess processing can be thought of as any action that that does not add value to the product. With regards to machinery lubrication, a great example of excess processing would be the handling of redundant lubricants on site. A key, initial objective for most sites in the development of their lubrication program should be the sound undertaking of lubrication consolidation. Over time, through the process of integrating new assets and switching lubricant suppliers, different lubricant brands and types tend to accumulate on site. While there are some instances where assets may initially require specific lubricants during warranty periods to maintain coverage, there is often flexibility to move to a site-specific lubricant with help from the OEM. With this being said, an initial equipment survey and routine follow-up surveys should take place at least every few years to understand which lubricants are currently onsite, which lubricants are being used and which consolidation measures can be used to reduce the overall number of lubricants being handled. Reducing the number of lubricants onsite drives ownership of the program and works to eliminate unnecessary associated storeroom overhead.

Excess Inventory – Lubricant Storage Management

Inventory is a structured and complete grouping of all parts, components and materials stored on site for future use. Excess inventory creates what many individuals in the Six Sigma world call “bottlenecking,” or a step in the process where the volume is limited. Maintaining more inventory than necessary can stalemate precious capital overhead and consume essential floor space in storerooms or reception areas. This is a specific concern within machinery lubrication as it can have an effect on cost and square footage and it can often play a role in the health of lubricants being staged in-house. Far too often, inventory management is overlooked within the realm of maintaining and sustaining a lubrication program. One of the first steps that should be considered in inventory management for lubricants is the minimum and maximum units of lubricants. This specific unit value should be driven off of site lubricant capacity, annual usage and supplier lead times. The minimum and maximum values should be reviewed on a biannual basis and adjusted accordingly. Another somewhat overlooked factor driving the minimum/maximum levels should be the shelf life of the lubricants. The shelf life of lubricants can range from a few months to several years depending on the type and additive packages associated with them. It is imperative that the reliability leaders at the site work with their lubricant suppliers to establish these specific timeframes. Once shelf lives and minimum/maximum values are established, sites should enforce the proper method for handling stored lubricants, i.e., First In, First Out. First In, First Out, or FIFO, methodology ensures that the site stages the most recently received lubricant in the back and pulls the oldest lubricant from stock upon use. This simple, yet effective process aids in minimizing the concern for lubricant health degradation of stored lubricants. The final parameter to discuss regarding inventory management is the use of quality assurance. Quality assurance (QA) can take place in lubricant reception in a three-phase process: 1) Hold for Test, 2) Quarantine and 3) Ready for Use. Upon reception, the lubricant is placed in the “Hold for Test” area. After sampling and test results are compiled, the lubricant moves to a Quarantine area for inspection and review if the lubricant failed testing, or to the “Ready for Use” area if it passed.

Just-In-Time (JIT) – Lubricant Storage

Just-In-Time (JIT) is a lean concept that is used to minimize process time within operation systems, to reduce storeroom capital overhead and to improve supplier response time. JIT provides a fantastic avenue for improving housekeeping at a site through minimized storage and better control. However, there are several machinery lubrication systems that need to be in place prior to implementing this practice-specifically minimizing storeroom lubricant storage. Employee engagement and ownership in the lubrication room is vital to ensure the proper amount of lubricant is always on site. Typically, it is a good idea to keep the dispensing station containers in the lubrication room full and have at least one full volume, based on the bulk storage container size, ready for replenishment. Once the drum in storage is used to replenish the dispensing container, a process should be set in place to automatically refill the storeroom drum. Additional planning should take place while setting up this system to address any past concerns (mass purchases) of ordering bulk lubricants based on need. Proper procurement staffing levels and supply chain engagement is another area of concern. Adequate staff needs to be available to address concerns upon arrival and storeroom personnel need to be actively involved in ensuring that concerns are minimized in the supply chain delivery process. Finally, it is important to have a strong relationship with suppliers.

This concept, while effective, will often immediately come to a halt, as it should, when leadership becomes aware of reoccurring supply shortcomings. To avoid this apprehension, it is critical to maintain the process and systems put in place.

Waiting: Improper Task Frequency

Waiting, a Six Sigma concern, can become a major issue during process optimization due to idling and the prevention of tasks being completed. One place this often rears its head in machinery lubrication is the improper selection of task frequencies. It is one thing to identify all of your site’s lubrication tasks and enter them into a Computerized Maintenance Management System (CMMS) to be completed, but it is another to ensure the proper frequency has been identified. Because sites generally have a limited amount of time available for specific maintenance and operation functions, it is imperative that an educated, thought-out approach is laid out to allocate this time in a proper manner to minimize waiting. A sound first step is to review the OEM recommendations regarding relubrication intervals, but habitual further inspection on these frequencies is necessary based on the application it will be used in, the environmental factors it will be subjected to and the industry the lubricant is being deployed in. Using bearing regreasing interval charts and formulas as well as site historical and reliability feedback mechanisms for oil and grease tasks further enhance the site’s lubrication responsibilities.

Transportation – Handling of Lubricants

Another concern within the realm of Six Sigma is transportation, or the transferring and handling of product throughout the process that does not add value. In the world of machinery lubrication, this concern falls under the handling of grease and especially oils during its cradle to grave process. While inventory management and just-in-time aspects have already been covered, transportation is often the largest concern of the three while guiding these lubricants through the plant. One of the keys to recognizing issues in this area is to properly identify a current and proposed process flow diagram. Greases are typically not a big endeavor and handling is often fairly simple in nature; oils, however, are a little more involved. The typical execution of oil handling tasks is as follows: at a plant, the oil starts at reception, then moves on to sampling and quality assurance in reception. It is then transferred to the lubrication room and bulk storage units.

OilSafe Bulk System


This is often followed by transferring the oil to top-up containers, which is sometimes shadowed by the use of funnels. Finally, it goes directly into the application itself. Although this seems like a pretty straight forward process, there are several steps involved. As such, there are countless opportunities for error. This can be reduced by minimizing handling steps, which as a result minimizes handling time, cross contamination and particle ingression. By establishing procedures, processes and documentation through handling development, sites become aware of unnecessary conduct and significantly improve the overall process. Correctly understanding and outfitting the lubricants’ transportation life cycle at your site is an important endeavor that should definitely be addressed sooner rather than later.


Time and Motion – Route Logistics and Development

One Six Sigma area that ties directly back to poor time management is time and motion. The primary difference between time and motion concerns and transportation concerns is what you are actually observing in the process. With transportation, sites are reviewing and assessing the actual product movement, as opposed to time and motion, where the individual’s performance of completing these tasks is being observed. This is especially important in machinery lubrication during the establishment of route tasks. Effectively optimizing lubrication routes based on location and type can significantly minimize waste in the forms of double handling, walking and other personnel process inefficiencies. Strategically developing route sequences based on the asset’s location relative to other equipment and the lubrication task being performed will greatly improve task completion rate and provide opportunities to minimize unwanted maintenance backlogs. While there are several other variables that need to be considered during route sequencing, it is especially important to take into consideration the criticality of the asset and the prioritization of task importance or ranking. As sites begin to grow and develop with new maintenance systems being put in place, these time and motion intricacies can be easily overlooked. As a result, this area of concern needs to be documented, reevaluated and addressed accordingly.

Kaizen Events – Lubrication Element Specific

One of the more common principles in Lean Six Sigma is the use of kaizen events. Kaizen is often a small event that acts as a tool used by owners and operators to identify, map and improve a process through detailed flowcharting and solicitation from all parties involved in the process. These brainstorming and execution events can last from several hours to several days depending on the complexity and length of the process being evaluated. The primary goal of kaizen events is to streamline the process by eliminating unwanted elements in the system through the collaboration of a dedicated, multi-departmental team. Several lubrication-related elements that would benefit greatly from the implementation of this principle in machinery lubrication include the introduction of lubricants, route logistics and development. It is imperative that an alliance is formed among maintenance and reliability personnel, area leaders and operators. This alliance should review lubrication processes similar to the ones mentioned above in order to understand what actions take place and which ones are necessary to the process. Due to the presence of several departments, these events can also function as an effective “buy-in” and culture change tool during the implementation phase of developing a sound lean Six Sigma program at your site.

Gemba Walks – Lubrication Plant Walkdowns

Gemba walks are another effective tool, used through the collection of team members, to identify site issues. These walks are generally organized for management and other personnel to break away from their contemporary office-related duties and perform a quick walkdown of an area. They are looking for specific observed work and areas where improvements can be made based on actual site performance. Observing, questioning and listening for addressable issues provides a swift feedback mechanism for concerns that might be overlooked by personnel working the area on a daily basis who have become accustomed to unnecessary workarounds and inefficiencies. Throughout this process, it is vital to provide positive feedback to the individuals being observed to encourage a positive culture. It should be verbally communicated that these walks are being incorporated to improve site performance, as well as the experience for the individuals performing these tasks. This principle can be used in machinery lubrication by the lubrication or reliability team to advance specific program improvements as well. These teams should already be meeting on some set frequency to communicate current issues, host mini training sessions, share project status updates and acknowledge recent site wins. One way to continue to build upon your program is to invite site role models from various areas and levels of the company to these meetings and execute a Gemba walk at the end of the meeting for a specific element within the lubrication program. Once again, a new set of eyes on the process can provide a fresh perspective on gaps in the program.

5-S – Lubrication Rooms and Satellite Cabinets

Another one of the more common principles in lean Six Sigma is 5-S. 5-S is a methodology used to effectively and efficiently organize and maintain a workspace. These workspaces can include plant floor operator areas, maintenance shops, office space, as well as the lube room. The primary goal is to drive a systematic focus around the sorting, setting, shining, standardizing and sustaining of an area to improve quality and reduce costs to increase site profitability. The two most prominent areas within machinery lubrication that directly benefit from the application of this principle are the lube room and remote satellite lubrication storage cabinets. Establishing 5-S audits as work orders with concrete frequencies in a Computerized Maintenance Management System can provide a steady, continuous assessment of the updated status of these areas. Another 5-S tip that supports follow-through is incorporating images and scorecards on the front of each area. These images provide detail on how the areas should be maintained and the associated scorecards deliver feedback on how well the area has been maintained over the past several audits.

Poka-Yoke – Grease Fittings and Quick Disconnects

Poka-yoke is a Japanese term that refers to proactive error-proofing in the lean Six Sigma work. This principle can be implemented in any industry by either altering the specific equipment or the method of execution to ensure a specific mistake is avoided. Poka-yoke typically involves identifying a specific issue through historical reoccurrence, verifying through data and resolving over time by means of design or process change. A couple of examples from the field of machinery lubrication are grease fittings and oil transfer quick disconnects. Grease fittings are generally available in hydraulic, button head and flush options. While each type is typically used for a specific application, different types can also be used based on the need. An example might be using hydraulic fittings for a polyurea thickener-based electric motor grease and a flush-style fitting for a lithium complex thickener-based electric motor grease. Using both of these greases in electric motors poses a major compatibility concern. Applying different grease fittings in a system with dedicated grease guns eliminates the concern for cross-contamination. Using quick disconnects with unique male and female fittings for oil transfer is another example of using Poka-yoke in machinery lubrication to minimize cross-contamination. Through the dedicated use of color-coding and exclusive quick disconnect fittings, transfer mismanagement should be a thing of the past.

Plan-Do-Check-Act – Lubricant Hardware Implementation

Plan-do-check-act, or PDCA is a process improvement cycle used to drive continued improvement in lean practices. Out of the several process improvement strategies, this format may be the simplest to apply and maintain. The “plan” section identifies an opportunity for improvement. “do” illustrates the action to be performed on a trial basis. The “check” portion allows for review and analysis of results and “act” is result of the trial base study with either new implantation based on the results or the enactment of the cycle to find a better, more suitable result. This PDCA cycle is often used during new projects, redesign of existing services, or any continuous improvements to existing processes. Much like any plant-related process, most machinery lubrication projects can benefit from the PDCA cycle. One specific area of this cycle to make note of in machinery lubrication is hardware implementation. While it is cost-effective in the majority of cases, there is an associated upfront fee with improving and optimizing hardware on equipment, so it is imperative to ensure reliability leaders identify the proper employment and function of hardware. While common hardware applications such as breathers and single-point lubricators facilitate a noted improvement, it may be beneficial to perform a PDCA cycle for these items on a small trial scale to ensure an appropriate result before moving on to a larger-scale application. Once again, this process denotes the proper brainstorming, trial installation and execution before running into more costly issues in the future.

KPIs – Lubrication Specific

Key Performance Indicators, or KPIs, are metrics established to aid in qualifying investment or focus on an area in the process. Within any proactive maintenance approach there should be established goals, actions to incorporate and complete these goals, as well as metrics or KPIs to measure the success of these actions. KPIs are necessary in the initial development or revamping of lubrication programs. Upon initially launching KPIs, the data should be easily attainable, agreed upon by the majority of the stakeholders in the program and have standardized updating frequencies. A few key examples of noteworthy KPIs in machinery lubrication are contamination compliance, route compliance, lubricant consumption and abnormal inspection rate. It is often stated that “what gets measured gets completed,” and that is the primary driving force behind developing worthwhile and effective KPIs.

RCA – Lubrication Related Failures

Root cause analysis (RCA) is another lean tool that uses multiple methods to aid in the discovery of failure-related mechanisms. It works to distinguish between the symptoms and direct root causes that drive inferior quality and inhibited performance. Identifying the root of the problem can lead to minimized downtime and defect elimination. Upon initial establishment, RCA is generally reactive due to instinctive responses. However, over time, this process can move to a more proactive state of equipment reliability. It is worthwhile to note that while this process can be completed by individuals, RCA often works best when performed by a group of peers with varying levels of experience, job duties and perspectives. RCA should be used on a continual basis within machinery lubrication to ensure proper lessons are learned and corrective actions are completed accordingly. This strategic process is often a key driver in promoting a change in reliability culture from reactive to proactive.

The Wrap Up

By now it should be abundantly clear that lean Six Sigma can be used to improve quality and consistency by the elimination of waste and process errors. Using these 13 principles, many industrial processes can experience the benefits of lean and Six Sigma principles, including lubrication reliability. As you progress in your career, it may be worthwhile to make note of how prior, somewhat unrelated experiences and lessons, such as lean Six Sigma principles, can indirectly affect you moving forward.

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About the Author

Matthew Adams is a technical consultant for Noria Corporation, concentrating in the field of predictive maintenance. He has experience in multiple condition-based maintenance technologies and fo...