Cement producers are in the enviable position of rarely being able to make as much product as they can sell. While this may seem like a business utopia, leveraging this opportunity in a highly cost-competitive market requires a continuous innovation.
“We’re sold out all year long and that’s just the way we want it, but we don’t have the luxury of non-production time. We must continually find new and better ways to balance both availability and utilisation of our production assets,” says Mike Ralls, plant systems administrator with Ash Grove Cement, the fifth largest cement manufacturer in the US.
For Ash Grove Cement this challenge was compounded by having to develop a standardised solution that worked for each of its nine separate production facilities.
The Ash Grove enterprise ranges from management finance and administration functions at headquarters in Overland Park, Kansas, to mining and production facilities in nine US states. Each plant operates as an autonomous production facility with capabilities ranging from mining of raw materials in the quarries usually adjacent to the plant, to systems that convey the raw materials, to production equipment, to bulk distribution of product to trucks and railcars. This involves equipment ranging from capital expense drilling and excavating systems to motors and power transmission belts, all of which need regular maintenance.
Further complicating Ash Grove’s situation is the tight production and planned outage schedules. “It’s a challenge to schedule maintenance work when you run 24hours a day, but usually we get a 2–4week period once a year based on kiln outage,” said Ryan Farr, corporate reliability manager.
While all phases of production are important, the kiln is the heart of producing cement. Despite its outward appearance of being a mechanical process, cement making actually is a chemical process. It transforms primary minerals (calcium, silica, alumina and iron components), which are found in limestone, clay and sand, into ‘cement clinker’ material that is ground and processed to create varieties of cement that possess specific setting times and hardness properties.
The chemical transformation of these mineral components occurs at temperatures from 1480–1650°C during processing in the cement kiln. The Ash Grove kilns are essentially large, ovens that rotate at about 3.5rpm. Finely ground raw feed is gravity fed into the kiln and processed until the transformation to ‘cement clinker’ is complete.
“If the kiln goes down, we’re looking at the possibility of losing as much as US$3000perhour, which makes the kiln one of our top maintenance priorities. Typically, the kiln drives our maintenance outages, which gives us a limited window of opportunity to do major overhauls,” says Farr. “We need to tightly manage what has to be done, who is going to do it, and what is needed to get the job done most efficiently for ongoing reliable operation,” he adds.
Having prospered in the competitive cement business for more than 120years, Ash Grove is adept at adopting change. In 1998 it implemented a Beta installation of Avantis.PRO enterprise asset management (EAM) system from Invensys, to improve its return on assets (ROA) and reduce cost by automating data collection on maintenance activities, primarily those related to keeping the kiln operating. Having proven itself on a test basis, Ash Grove began rolling the Avantis solution out to the remaining facilities the next year.
“Our long-term goal was to install Avantis at each of our facilities for a well-defined EAM process to support equipment performance reliability while interfacing with our financial software, JD Edwards One World,” said Ralls.
Ash Grove’s Durkee, Oregon, facility was first on the EAM rollout roster. “Our original need was maintenance functionality and some cost tracking information, mostly a data capture ‘get it into the system so we don’t lose it’ type of solution, but when we saw that Avantis could also help us sort and interpret this data, we were pretty excited,” said Bernard Sherin, maintenance manager at the Durkee plant at the time. With the global roll-out underway, Ash Grove set out to improve equipment reliability and cost savings further by tapping EAM functionality for enterprise planning and scheduling, document management, regulatory compliance and inventory management.
The expanded EAM implementation synched nicely with corporate maintenance excellence process (MEP) initiative designed to improve the reliability of Ash Grove’s equipment and process to world class levels. The MEP programme is a work management process designed to improve maintenance via combined planning, scheduling, preventive maintenance (PM), and improved working documentation. Ash Grove found that MEP also aids productivity by supporting a positive plant-level attitude toward reliability.
“In the past the approach was reactive – something had to break and then available resources were deployed to fix it. Now with the combination of MEP supported by Avantis we focus on preventive and predictive maintenance with detailed activity planning and scheduling,” said Farr.
Planning and scheduling
“Following safety, our top priority is minimising downtime of revenue-producing equipment so planned outages of this equipment drive our planning, says Sharon McGuire, planner/scheduler at the Durkee facility.“Proper planning gives us more control over the situation, but requires facility-wide co-ordination, and that is one area where the Avantis software has proven to be particularly helpful.”
The Avantis system enables Ash Grove management to share maintenance data from diverse, geographically separated operations, covering several square miles of quarries and the cement production plant. It is a computerised maintenance management system (CMMS) that uses an ‘entity’ concept to enabled tracking of costing and maintenance activity. “Parent-child” relationships can be set up easily to build detailed hierarchies for cost rollups and operating statistics.
This detailed history of equipment information enables supervisors to analyse failure histories, track failure causes and take action accordingly. Maintenance parts inventories can be better managed, especially when dealing with large numbers of unique and low unit value items that can often be subject to unpredictable demand. Workflow can be better planned and purchasing and procurement functions can be tied directly into planned outage maintenance programmes.
The software also supports contingency planning for unanticipated equipment failures.
Technicians can review work backlogs easily, adjust work schedules, and determine appropriate maintenance procedures by studying the history of the equipment. Pre-entered coding helps technicians determine which equipment must be shut down during the maintenance and which can continue running.
To help all maintenance teams stay on top of required maintenance, Ash Grove has an open access policy to relevant information by all Avantis users throughout the enterprise from maintenance to management. This is particularly useful for managing work requests. For instance, if a guard on a piece of rotating equipment needs to be replaced, the equipment operator can enter a work request from his station. Planners and schedulers in another office will review the work request, schedule the repair, and define the most efficient procedures. The system then generates the work order automatically, and places it in a backlog, for regular review and reprioritisation, as needed. The system issues work orders to technicians automatically, who replace the guard, enter details into the system, which notifies the operator that the job is done and invites review and comment.
To enhance the scheduling and planning efficiency further, Ash Grove added Avantis VIP Advanced Scheduling software, which helps ensure that all people, tools, assets, parts and other resources needed for a project are lined up and available to the technician. “The VIP software helps us schedule the maintenance and measures schedule compliance. It enables better employee work utilisation and facilitates changes in plans and schedules,” said McGuire.
Ash Grove uses Avantis VIP in conjunction with handheld PDAs. Planners download work orders to PDAs, which are given to technicians at the beginning of each day. The work orders can include information on labour, materials, tools, drawings, and any special instructions for the job. As tasks are completed, the technician checks them off. When the PDAs are docked at the end of the day, the planner can see what work was accomplished, what work is outstanding, and what emergency work came in during the day. The VIP tool can then be used to coordinate sick call-ins or any other schedule changes that need to be made, reconcile it with new work orders that came in, and update the PDAs for the crew when they report to work the next morning,
Electronic documentation
In terms of electronic documentation, the Avantis.PRO software builds a detailed history of equipment information based on day-to-day maintenance activities. Equipment statistics include hours of operation, cause and frequency of downtime, and labour and material changes, all of which can be easily reviewed and analysed. “We can look at historical data and trend it to evaluate whether we need to spend more or less effort in a particular area,” Farr said. “It’s given us an easy way to determine whether a particular piece of equipment has had an inordinate amount of work done on it. With proper cost justification, we can judge whether we should replace any equipment that’s costing too much to maintain.”
Improved regulatory compliance is yet another benefit of the EAM system. According to a Federal Environmental Protection Agency (EPA) regulation called the Portland Cement Maximum Achievable Control Technology, or PC MACT, all cement plants had to be fully compliant by June of 2002. Durkee plant management used the Avantis system to collect and process all data that supported compliance with this particular programme.
“By law we are required to document these incidents and the inspectors want to see it. They want to know what time the incident occurred, what we did about it and what time the emissions was abated,” said Farr. “Avantis provides this documentation to validate our actions. Without this documentation, we could face serious fines. In the past Ash Grove has paid significant fines because a plant may have abated an emission within the appropriate time frame, but had no substantial way to prove it,” he added Farr.
Ash Grove has recently upgraded to Avantis.PRO4.1, which provides the Oracle9i support necessary for integration with the ERP system. They are also working on integration with an enterprise-wide network that will enable management of all Avantis clients from the Overland Park headquarters.
