Reveal Hidden Problems with This Top Lubrication Metric

Bennett Fitch, Noria Corporation
Tags: oil analysis

Lubrication is full of metrics. Whether it’s oil analysis, equipment uptime, filtration or route compliance, all have a role to play. There is one metric in lubrication that has proven extremely important and effective at revealing hidden lubricant-and equipment-related issues. This metric is known as Lubricant Utilization.

In short, this is a Key Performance Indicator (KPI) based on the volume of lubricant applied to machines, relative to the amount of lubricants that have been disposed of over a period of time. But more importantly, the data collected on Lubricant Utilization is directly associated with other important metrics and KPIs across all stages of the lubricant and can define some KPIs for the lubrication program. Some of these indicators may focus on controlling overall lubricant expenditures while others focus more on minimizing risk and reliability issues. Regardless of the indicator, it must begin with establishing the metrics and tracking good data.

Tracking the Application of the Lubricant

Lubricants, like many other consumables, are likely monitored by some sort of inventory tracking system, usually starting in a warehouse. Here, the warehouse management tracks the reception of each lubricant, by container or in batches as they arrive and are put into a storage location. Lubricants can be delivered in many different containers, such as pails and boxes of tubes for grease or in drums, totes or quart/gallon-size bottles for oil. But regardless of how it is contained, an amount of total lubricant delivered should always be known and recorded. Knowing this total delivered amount and associated costs are metrics by themselves, as well as monitoring when each lubricant reaches inventory minimums and maximums. But there’s more.

Warehouse metrics are more than just the inventory of your lubricants in storage. It can be an important piece of data that stretches across your entire plant’s overall equipment reliability and helps monitor plant performance. As these lubricants become needed for equipment, inventory management can monitor their exits from the warehouse with date, time, by user, which machine(s) it will be used in, how much, how often, and so on. As this data is collected, it populates the first important piece of useful information for Lubricant Utilization.

Tracking the Removal of the Lubricant

For a variety of reasons, lubricants become removed from the machines they are used in. The most obvious and preferable reason is because they are intentionally drained by maintenance during oil change procedures. This happens either because of a scheduled oil change as a PM task or because compromised conditions of the lubricant have triggered a condition-based oil change. When this happens, the volume of oil is collected in an appropriate waste container which is subsequently disposed of in a larger waste oil storage tank. During this process, the volume of disposed oil should be noted as part of the maintenance activity. This can be estimated by using volume markings on the sides of the disposal container, or any other suitable means. Oil disposal is going to be easier to track, but it is important to note that grease can sometimes be tracked as well.

Is the lubricant applied to the machine always the same as the lubricant disposed of? Not always. There are many reasons for this expected discrepancy. Exploring these reasons and tracking lubricant consumption can be important. In one way or another, the constituents that make up the lubricant end up somewhere. When the lubricant is removed from the machine for unknown reasons, it also removes its ability to provide key lubrication functions and risks lubricant starvation on the equipment. Aside from scheduled oil drains, here are some examples of possible lubricant removal mechanisms that may occur:

Some of these lubricant removal mechanisms may be ordinary or seem negligible in volume, but it could still become a root cause for equipment issues. Some of these mechanisms may be highly aberrant and even difficult to quantify in terms of volume for some of the more unique removal mechanisms. Nevertheless, awareness of these possible events is important and should considered during investigation.

In some machines (particularly smaller sumps), every drop is a critical contribution to effective lubrication and when it is lost, it can put the equipment at risk. Tracking the known quantities of lubricant drained becomes an excellent indicator of the unknown and unexpected quantities of lubricant loss.

Calculating Lubricant Utilization Metrics

From a plantwide perspective (as a macro metric), quantifying the total volume purchase or segmented by totals for each lubricant type should be easy. This data can then be compared against either the known volume of lubricant disposed of (to calculate the Lubricant Utilization Ratio) or the total machine charge in the plant (to calculate the Lubricant Consumption Ratio), all over a fixed time interval, such as yearly. Here is a further explanation of these two ratios.

Note: An increase in lubricant life assumes there is also condition monitoring in place. Otherwise, simply leaving the oil in the machine longer will put the machine at risk of failure. For this reason, the Oil Consumption Ratio must be monitored alongside condition monitoring and failure rates KPIs.

A common Oil Consumption Ratio goal would be a reduction of 50% each year until a Consumption Ratio approaches 0.2, which will also vary by industry and equipment type. By year three in the example, the ratio was reduced to 0.29 which was a total reduction of oil consumption of more than 85% across the plant.

From a machine-specific perspective (as a micro metric), quantifying the total volume applied to each machine or group of similar machines over an oil change interval is usually achievable. Rather than a lubricant purchase volume, this includes the initial volume of oil put into the machine(s) and any subsequent top-ups until the schedule oil change. Similar to the macro version of this metric, this data can then be compared against the known volume of lubricant from the machine(s) that was disposed of to calculate the Lubricant Utilization Ratio or compared against the lubricant charge per machine to calculate the Lubricant Consumption Ratio. Since these metrics are calculated for specific machines, the reasons for a higher or lower ratio value can be more exclusively observed.

These are examples of metrics that can be developed as important performance indicators of the lubrication program. If abnormal data trends are discovered, this can help uncover a lubricant removal mechanism taking place and reveal hidden problems within the machine.

Creating Key Performance Indicators by monitoring Lubricant Utilization

From the initial delivery of the lubricant to the eventual lubricant disposal and removal from the plant, there are many metrics and key performance indicators that are directly connected to Lubricant Utilization. Here are a few examples, as well as where they are connected to each of the six lifecycle stages in the Ascend™ Methodology:

Conclusion;

Analyzing Lubricant Utilization within the plant is an important metric for revealing many hidden problems at all stages of the lubricant lifecycle. First, steps must be taken to collect good data, which might be easy in some areas but more challenging in others. Certain data will never be fully collected, such as with some of the lubricant removal mechanisms mentioned. But there is good news. While putting the practices in place to collect and track volume use, where possible, you will uncover opportunities for improved lubrication along the way and start to see how the benefits of corrective actions can already be achieved. In fact, implementation may be an ongoing effort. Regardless, Lubricant Utilization is more than just a metric. It has a lifetime of benefits and has proven to be a powerful performance indicator for the entire lubrication program.