What are the essential elements of a world-class pump reliability program?
What best practices lower total cost of ownership and which ones create little value?
Is mean time between failures (MTBF) the best measure of improved performance?
Roquette America’s search for the answers to these questions led the global leader of innovative nutritional ingredients processed from renewable, plant-based raw materials on a journey in search of excellence.
From an initial effort to create written standards for pump design, operation, installation and repair, a fully integrated asset management program slowly emerged. As the program matured, it became apparent there were five essential elements of best class performance.
Having a simple, easily understood program.
Effective communications of the program's elements to all internal and external stakeholders.
Emphasis on training and execution. Like firefighters or first responders, it is important to standardize processes. When variability is minimized, bad actors can be better identified and a defect elimination culture can become firmly established.
Development of a continuous improvement culture, where new ideas are incorporated into the low variability processes created through standardization.
Development of a formal audit process. This ensures those ideas that lower total cost of ownership are adopted and those that do not are quickly discarded.
Before any journey begins, one must have both a vision and a mission.Roquette's vision for maintaining the pump asset class in all of its plants is simple: All pump failures are avoidable. The two primary failure modes associated with centrifugal pumps are bearings and mechanical seals.In his technical paper series, William McNally of the McNally Institute stated that the L10 life of a radial bearing in a Durco Mark II pump, size 3 x 2 x 10 is 300 years. In his 2014 keynote address at the Society for Maintenance and Reliability Professionals (SMRP) annual conference, Heinz Bloch indicated only 9 percent of bearings reach their L10 life. And ask seal manufacturers how many of their products fail due to complete face wear and they will tell you almost none. Therefore, like a safety culture built on the premise that all accidents are avoidable, Roquette America believes almost all its pump failures are premature in nature and, therefore, avoidable. The company will change its opinion when MTBF exceeds 10 years! This vision gave birth to the following:
Roquette America is committed to managing all facets of its pump program to best practice levels, including design, repair, storage, installation, maintenance, and bad actor identification and resolution. It is committed to this mission so that it may increase equipment reliability and reduce the total cost of ownership for this asset class.
But a vision and mission, in and of themselves, do not produce results. Reliability initiatives, such as a pump asset management program, have a greater chance of success if they are strategically designed.Roquette utilized a plan-do-check-act (PDCA) action cycle to develop the scope and sequence of its program. Timing and sequence are critical; getting too many change initiatives started at the same time overwhelm personnel and rolling out actionable steps in the wrong sequence increases the likelihood the initiative will fail. The PDCA action cycle is shown in Figure 1.
The PDCA action cycle
It cannot be stressed enough the importance of the planning step in the PDCA action cycle. Several questions should be considered:
Is the activity well-defined? What scope will be covered under the initiative?
What resources will be required to ensure the initiative can be successfully completed? Are the resources committed to the assigned activities and do they have sufficient time to complete them?
What is the anticipated payback for the initiative? Based on the required resources (e.g., time and money), will the payback meet company hurdles. Will competing initiatives produce a better return on investment?
Is there buy-in from all stakeholders participating in or committing resources to the initiative?
What needs to be done before rollout? Should the activity be rolled out in stages or all at once?
How will success be measured?
During the planning stage, it became obvious that Roquette America needed to break the program down into smaller, more manageable steps. Defects were found throughout the process. If the company was committed to creating a defect elimination culture, it had to eat the elephant one small bite at a time. There were too many areas in which the pump program was not performing at best practice levels and the data necessary to make informed decisions did not exist. The company concentrated its initial efforts on standard development and the creation of measures that captured the current state of the program. This required meaningful key performance indicators (KPIs) and standardized failure modes. It was at this time that Roquette created the KPI, $ per pump type/per year, adopting it in place of MTBF. In an effort to maximize MTBF, the company was, at times, running pumps to catastrophic failure. The cost of the collateral damage, which occurred in the last few weeks of the asset's lifecycle, far outweighed the extra lifetime gained. This concept is illustrated in Figure 2. Letting a seal or bearing go beyond incipient failure results in higher repair costs. The company's own research indicated that total cost of ownership was minimized somewhere around 90 percent of useful asset life.
Development of best practices standards was a collaborative effort between internal and external stakeholders. Representatives from maintenance reliability, storeroom, purchasing and partner repair facilities were involved. Emphasis was placed on partnerships that were built on value instead of low cost. Shop audits were performed to ensure Roquette partnered with repair facilities that were aligned with its mission. It was important to select shops that provided more than repair services. The company sought partners who could help it identify opportunities to consolidate inventory, provide robust failure analysis capability and provide engineering services capable of identifying and eliminating defects. Price was only used as a deciding factor between best practice shops that were in alignment with Roquette's vision for asset class management.
Cost of pump repair as a percent of useful life
The next two focus areas were storeroom inventory consolidation and best practice storage. Inventory consolidation turned out to be one of the most lucrative opportunities since over the years, Roquette America had acquired a veritable museum of different types and vintages of pumps. Several examples of pumps with spare overstock existed due to the practice of removing pumps from service and keeping them for spares. New material codes were created as pumps were upgraded, even though, in many cases, the models were dimensionally equivalent to those they replaced. Many times, one-off pumps were installed by engineers on projects, rather than purchasing a more common pump found in the plant.
2014 program management savings YTD through October 9
Many of these one-off designs had one-to-one field to spare ratios. Standardization to preferred pump types provided additional consolidation opportunities. Cumulatively, these initiatives resulted in a tremendous cost savings opportunity. Consolidation and targeted obsolescence allowed Roquette to forego repairs as pumps failed. It is said that simplicity is the mother of invention and, in this case, simplifying inventory led to better cycle turns and improved storage practices. Roquette had to clean up the clutter to see the forest through the trees. Its optimization efforts removed 102 pumps from its storeroom inventory over a three-year period, saving over $1 million in the three asset classes managed with this approach - pumps, motors and mechanical seals. Figure 3 shows 2014 year-to-date savings through early October.
Using a first in, first out (FIFO) inventory management system and a just in time (JIT) inventory management approach ensured pump cycle turns were optimized and no pump accidently sat in a corner unused and forgotten. A FIFO staging area made it easier for craftspeople to check out the oldest pump first.
Once standardized repair and storage procedures were in place, the focus switched to bad actor resolution and defect elimination. Data indicated that many of the company's pumps followed a typical bathtub curve failure pattern. Chronic bad actors and human error contributed to a high infant mortality rate. Resolving bad actors and eliminating defects significantly increased aggregate MTBF and reduced total cost of pump ownership. A unique process was developed by which the root cause of chronic pump failures was identified. Primary failure mode data helpedin creating this process. Figure 4 shows a Pareto analysis of pump failure modes since the program's inception.
Pareto analysis of pump failure modes
Forty-five percent of Roquette's pump failures were from mechanical seal leaks. Mechanical seals leak for a variety of reasons. If the mechanical and operational issues causing the seal leaks were eliminated, the root cause of the majority of remaining issues would be inadequate seal water back pressure or the quality (cleanliness) of the flush fluid. A failure analysis spreadsheet was developed to identify the root cause of seal leaks, the primary failure mode. As bad actors were identified, the lead vibration analyst was dispatched to complete a comprehensive machine assessment, identifying mechanical issues, such as base deterioration, looseness, misalignment, or excessive pipe strain. If issues were found, the cost of corrective actions was estimated to determine whether eliminating these defects would pay for themselves through increased reliability.
Once the machine assessment was completed, the pump's design and its fitness for duty were assessed. The importance of this step cannot be emphasized enough. Most pump designers will tell you the overwhelming majority of pumps are oversized. Many of Roquette America's bad actors ran far left or far rightof the pump's best efficiency point (BEP). Radial forces are minimal at BEP. Operating off BEP increases radial forces, causing premature seal and bearing failure. Pump efficiency greatly improves as you operate closer to BEP. Often, the energy savings, utility rebates and the increased pump MTBF will pay for the cost of pump replacement.
If a pump passed through the first two assessments without triggering a corrective action, seal water pressure or flush fluid quality issues were investigated. The plant is very old and the city's water pressure fluctuates in many areas. Over the years, Roquette's API Plan 54 water system has not been upgraded as the company added pumps to the loop. It has found that Plan 53A (seal pots) is an effective solution in many cases to address inconsistent water pressure. In each case, bad actor improvement projects were cost justified. Lifecycle cost (LCC) analysis was used to determine which solutions offered the lowest total cost of ownership. An example of an LCC analysis that was completed to resolve a bad actor is shown in Figure 5.
LCC analysis for Waste Tank E pump project
Failure mode and effects analysis (FMEA) identified substandard work practices that contributed to infant mortality. Targeted operator and craft training, as well as an operator basic care checklist for pumps and seals, were developed from the primary human error failure modes. The individual initiatives of Roquette's holistic program fit together like pieces of a puzzle to form the improved picture that is the company's current asset management program. The results have been quite satisfying.
Total cost of ownership, as measured by the $ per pump type/per year metric, indicates Roquette America has reduced the overall cost of ownership for its most common pump(Goulds 3196) by approximately 22 percent year-to date as compared to the 2011-2012 baseline. Figure 6 shows year-to-date results for the 3196 ST, MT and LT series pumps.
Roquette's $ per pump type, per year
Developing a best in class asset management program involves many things. First, using a strategic approach where all facets of the program are considered before rollout will produce better results than a less systematic one. Always remember the importance of employee engagement. Creating a vision of excellence and passionately communicating it to all stakeholders energizes your team and makes them want to be part of a best in class program.
The journey to reliability excellence is long and hard, and it is not for the faint of heart. Great leaders embrace the challenge and assume the mantle of leadership with zeal. The fact that you read Uptime magazine demonstrates your commitment to excellence. Adopt the best practices found in this magazine at your plant and become the type of leader who can transform a culture.
Phil Beelendorf is the Maintenance Technology Senior Manager for Roquette America Inc, located in Keokuk, Iowa. Phil is responsible for the creation and execution of the Roquette America reliability excellence strategy. He is passionately committed to leading a team of talented individuals in pursuit of best in class performance.
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