Career Development

Reliability-centered maintenance optimizes production and increases safety

In this installment of What Works, plant-wide reliability training saves one hot strip mill $2 million.

The ArcelorMittal USA Flat Roll Operations (www.arcelormittal.com) is comprised of 12 operating facilities employing more than 17,000 people. The World Class Equipment Reliability (WCER) team at the ArcelorMittal Burns Harbor Hot Strip Mill achieved dramatic results in a one-year period. Total savings in 2010 were $2,076,900. Other positive benefits include increased safety and a cleaner work environment.

During 2007, senior leadership determined that in addition to investing capital in production equipment replacement or upgrade, a complete and consistent reliability business process should be developed and implemented and coupled with world-class reliability practices and tools to reap the full benefits of any capital expenditure.

To launch its WCER effort, ArcelorMittal-USA (AM-USA) formed a central team with members from each U.S. site. They partnered with Ivara (www.ivara.com) to learn and use the Ivara reliability process, practices, technology and methodology. Ivara consultants trained this central team, and the teams were deployed to their plant sites to launch the WCER initiative.

The objective of the training and coaching was to prepare the AM-USA central team members to be the internal WCER trainers and coaches for their operations. This development effort was completed in 2009, leaving each plant site with a central WCER team of internal reliability practitioners to drive and support future reliability improvements.

The Ivara EXP Enterprise software was the tool selected to support the AM-USA WCER implementation. The software was installed on corporate servers using a single database for all U.S. operations. A custom interface to the Tabware CMMS was designed, tested and implemented to manage the full scope of the WCER business process.

In 2009, the Burns Harbor Hot Strip Mill (HSM) operation was identified as a high-priority candidate for WCER implementation. It was experiencing an average delay rate of more than 22%. Significant improvements in production equipment reliability were necessary to achieve the 2010 business plan of 18% average delay rate. Through much of 2010, the mill wasn’t operating at full capacity. However, as economic conditions improved, the production requirements have increased. This opportunity was another reason to take action to reduce the high delay rate in a sustainable manner.

A team was assembled to focus exclusively on applying the WCER approach and methodologies to begin addressing the mill’s reliability problems. This began with implementing proactive asset management business processes. The initial area of focus was the finishing mill, which consistently experienced the highest delay rates at the mill.

Critical to program success was ensuring that the HSM WCER team, which represented 6% of the maintenance workforce, be able to focus exclusively on proactive activities and not be pulled away to deal with day-to-day duties. Area leadership demonstrated its support by assigning 10 people from the mill to the WCER effort full-time. This included seven from the HSM maintenance group, one from operations and two from the operations technology group. In addition, an outside asset coach was brought in to lead the effort.

The Burns Harbor Central Reliability Team provided WCER skills training and coaching to the HSM team members and ensured that the improvement effort was performed in accordance with the overall AM-USA WCER standards.

During 2007, senior leadership determined that a complete and consistent reliability business process should be developed and implemented and coupled with world-class reliability practices and tools to reap the full benefits of any capital expenditure.

In preparation for the effort, training profiles and collaterals were developed to support the key roles in the WCER organization. Where possible, computer-based training that incorporated knowledge testing was used to deliver the skills upgrades. This was supplemented with classroom training as needed to fulfill role requirements. Everyone on the team has a competency profile that identifies the training completed and the certifications attained. Providing comprehensive skills training followed by field coaching effectively prepared this team to deliver strong results while enabling them to educate others at the mill about the value of a proactive approach.

The HSM-WCER team was built to ensure the delivery of a world-class equipment reliability business process. One asset coach coordinated overall WCER development and implementation efforts. Two reliability practitioners facilitated the work identification activities. Two equipment specialists implemented the recommended action plans in the form of indicators, inspection routes and corrective tasks within the enterprise software. They also were responsible for alarm acknowledgement within the EXP software and the continuous reliability improvement of production assets within their area.

Three equipment inspectors performed the equipment inspections following the routes built in EXP and entered the equipment conditions in handheld inspection devices. They provided feedback to the equipment specialists to improve the quality of the indicators and routes. One lead planner/scheduler planned and scheduled proactive inspection and corrective activities to address abnormal equipment conditions. This role is critical to the weekly downturn planning/scheduling activities, which now incorporate much more proactive work.

Two planners handled detailed inspection and corrective maintenance job planning within the Tabware CMMS. This includes identifying parts, materials, manpower, procedures, safety information, permits and tools needed to perform corrective maintenance work efficiently, effectively and safely. One operator inspected equipment and provided input to the work identification analyses.

An asset prioritization analysis using Ivara EXP determines the order in which production equipment undergoes work identification. The output of this analysis is a relative risk number assigned to each system identified. The relative risk number is the sum of the magnitude of consequences of failure of the system in terms of a number of criteria, including safety, environment, quality, throughput, cost and customer service, multiplied by the likelihood of failure. The relative risk list, sorted in descending order, was a starting point for the WCER team to develop its work identification plan. However, relative risk wasn’t the only variable considered in the development of the work identification analysis plan.

Another key factor used in determining the sequence of analyses was the potential that an analysis had to be applied to multiple assets. The team identified systems that were similar to others as these offered the opportunity to fast-track both the analyses and the implementation through the use of templates within Ivara EXP. Failure modes and associated action plans developed through formal work identification analysis for one asset are copied to another asset, taking along the detail of the indicators built to inspect for asset condition and the corrective task required when the indicator condition is found to be abnormal. A validation of these failure modes, condition indicators and tasks is performed with equipment operators and maintenance technicians before activating them to ensure they actually apply in the operating context of the new asset. The use of this software functionality allowed for rapid implementation and deployment of technically based maintenance programs for the like type systems at the mill. The strategy to use templates and analysis copying enabled the HSM-WCER team to implement 11,236 indicators within 12 months.

AM-USA WCER’s leadership identified four options to be used for formal work identification, including Aladon Reliability Centered Maintenance (RCM), Aladon Maintenance Task Analysis (MTA), Current Inspection Implementation (CII) and RCFA. These approaches vary in their level of rigor from the very detailed analysis of RCM to the less rigorous approach of CII. The approach selected depends on a number of factors, including equipment complexity and criticality, availability of knowledgeable resources, current and targeted equipment performance, and the current level of knowledge of the equipment operation and its performance. The BH-HSM leadership chose to use only MTA and RCM for its analyses. Key reasons for this decision included:

  • Thorough program documentation was identified as a requirement of the effort
  • Sufficient resources available to support all elements of work identification performance and implementation
  • They are strong supporters of technically valid work identification techniques
  • MTA specifically offered the potential for rapid program implementation within Ivara EXP and therefore rapid deployment of the improved proactive inspection activities.

Work identification analyses were conducted with the participation of trades and operating personnel from the finishing mill area. Once analyses were completed, the results were compiled into summary reports for area management team review and approval.

Following approval, equipment specialists implemented the action plans through indicators developed within Ivara EXP. An indicator is defined as a point of inspection for an asset that highlights whether a specific failure mode that could potentially lead to a subsequent asset failure is developing. The indicators were organized into logical groupings called routes, which are the indicators to be inspected by a specific role at a specific frequency for a given asset operating condition. New routes are validated by the implementer working with an inspector to complete the route to identify any changes to indicators or their sequencing, which would improve inspection quality and effectiveness. Once validated, the routes are activated and data collection and analysis begins.

The 11,236 indicators implemented to date are organized into 386 inspection routes. Of these, 45% are performed while the equipment is running and the balance during a shutdown.

The team used the Ivara EXP Asset Health Indicator Panel to manage equipment problems by exception because the software consolidated sources of condition data, analyzed the data based on rules and calculations, and provided a central view of asset health. Those responsible for an area are alerted if a problem arises, based on the condition data input from various sources.

The HSM WCER team aimed to maximize the reliability program effectiveness through the use of predictive technologies for asset inspection wherever possible and practical. This resulted in the extensive use of vibration, thermographic, ultrasonic and oil analysis techniques. Predictive technologies already have proven successful in identifying non-normal asset conditions for follow up.

The HSM WCER team built KPI dashboards within Ivara EXP to track and report on the program, including strategy development, implementation, performance management and work management. This information provides the means to assess execution of the activities and it highlights problems well before they degrade equipment performance.

Over a period of 12 months since its launch, the program realized a total savings of $2.1 million. These savings came from several areas.

  • Unplanned downtime of production assets was avoided through equipment inspections aimed at identifying potential failure conditions and through modification of production equipment to eliminate specific failure modes. The abnormal conditions were addressed with appropriate corrective action before failure. The equipment failure avoided resulted in a savings of $1,282,500.
  • The information provided by equipment inspections coupled with improved planning and scheduling practices improved efficiency of corrective work performed during scheduled shutdowns. Shutdown-scheduled compliance has increased from 65% to 80%, resulting in a manpower savings of $394,400 on an annual basis.
  • Reduced asset downtime improved HSM work ratio and translated to a savings in energy (gas/electric) consumption of $400,000.
Delays continue to improve at Burns Harbor Hot Strip Mill as a result of this team-effort program.

Specific examples of unplanned production equipment downtime avoided through identification and correction of abnormal equipment conditions or redesign of the equipment are many.

A single modification saves $200,000 per year by avoiding unnecessary bearing failures. During the analysis of finishing mill stand No. 1 (F1) revealed that bearings failed on average of twice per year at a cost of $100,000 per bearing. These failures were caused by lubrication hose problems. The analysis team recommended that the hoses be redesigned to eliminate this bearing failure cause. This redesign has been completed and no bearing failures have occurred since the change.

A vibration inspection of Finishing Mill No. 6 main gearbox was identified and implemented. Routine performance of the inspection highlighted a high vibration condition. Further investigation triggered by this abnormal vibration reading identified the likely cause to be a lack of coupling lubrication. The coupling was lubricated properly and a subsequent vibration reading was normal. If the coupling failed, the corrective action would be to change the set of main drive reduction gears on which the coupling is press fit. The cost to recondition the gear set and coupling is $385,000, which is the cost avoided by taking corrective action when the abnormal condition was detected.

An infrared thermographic inspection revealed the temperature of four main drive spindles on the finishing mills was excessive. Investigation revealed that grease fittings failed and, as a result, proper lubrication wasn’t being supplied. The grease fittings were changed during the next shutdown and the spindles greased. Subsequent IR inspection showed the spindles to be running at normal operating temperatures. Each unexpected spindle failure would have cost $120,000.

A lubrication oil analysis task was identified for the gearbox on each finishing stand. During the first inspection, three of the seven gearboxes had extremely low oil levels that triggered critical alarms in Ivara EXP. The gearboxes were drained and refilled. A failure of any one of them would cost $38,000.

The HSM WCER effort also has driven an improvement in effective use of manpower during weekly scheduled shutdowns. In the past, shutdown work schedule compliance averaged only 65% because of the large amount of work identified during the shutdown. Much of it was found to be critical enough that it had to be addressed before returning the mill to operation. This meant that some of the planned and scheduled work was delayed. The manpower applied to the newly found work wasn’t used efficiently because the work being performed wasn’t planned in advance. Much time was spent searching out parts and tools to complete these jobs.

Equipment inspections developed and implemented through WCER ensured that more of the critical corrective work is identified in advance, allowing shutdown jobs to be planned and scheduled fully. The manpower available on shutdowns is now used more efficiently on planned activities and the weekly work schedule compliance for shutdowns is now 80%. This translates to a savings of $11,600 per shutdown, or $394,400 annually.

The average production equipment delay rate in 2008 and 2009 was more than 20%, with 2009 averaging 22% delay rate, or 78% working ratio. Since starting the

WCER in the HSM, the average delay rate for 2010 has dropped to 18%, which is a working ratio of 82%. Though this improvement hasn’t translated into additional profit yet because of current economic conditions, it resulted in significant gas and electric energy savings in the amount of $400,000 year to date. Once economic conditions improve and markets return, the increased working ratio will deliver a greater profit to the organization through increased production capability.

Additional benefits of the Burns Harbor HSM WCER effort which can’t be quantified in terms of cost savings include increased focus on effective shutdown work planning, resulting in improved worker safety. The WCER team focused on cleaning up the finishing mill area to perform more effective inspections. This improved working conditions for area personnel and, in turn, improved worker safety. With the exception of one position that was filled from outside, the entire WCER team was formed from existing HSM personnel without increasing the labor budget. Therefore, this improvement effort came at little additional cost and already delivered a significant savings.

As a result of improvements made in the finishing mill area of the HSM, the WCER team has been directed to implement a proactive maintenance program for the run out table and coiler area. Additional resources will be needed for this work and the team will be drawn from the existing HSM workforce. With this increased scope of work, the WCER team is responsible for a reliability program for 50% of HSM assets. The team will continue its work until every HSM asset has been addressed. It’s clear that by taking a focused approach to reliability improvement, providing teams with essential skills, tools and information needed to be effective and looking for opportunities to leverage the work done, the WCER team at the Burns Harbor Hot Strip Mill has achieved dramatic results in a one-year period.