Asset Management: Predictive Maintenance

Not that long ago, maintenance was the corporate black hole-the cost center one couldn't ignore, escape, or seemingly control. Capturing, analyzing, and sharing meaningful maintenance costs is key to lowering operational costs, improving efficiency, and effectively managing assets.A look at the balance sheet of most manufacturing companies reveals the biggest dollar assets are plant, prop...

By Dave Harrold, CONTROL ENGINEERING July 1, 1999

Keywords

Process control & instrumentation

Asset management

Predictive maintenance

Sidebars: Improving asset performance

Not that long ago, maintenance was the corporate black hole-the cost center one couldn’t ignore, escape, or seemingly control. Capturing, analyzing, and sharing meaningful maintenance costs is key to lowering operational costs, improving efficiency, and effectively managing assets.

A look at the balance sheet of most manufacturing companies reveals the biggest dollar assets are plant, property, and equipment (PPE), followed closely by raw material and finished goods inventory.

When a modern day race team sets out to win an endurance race, driver, pit-crew, engineers, mechanics, statisticians, technicians, owners, and suppliers each pay special attention to reliability. The same should be true when a manufacturing company embarks on a journey to world-class status. Unless production, engineering, and maintenance groups perform similar to a high-performance race team, the journey will likely end in disappointment and possible disaster. Development of a Reliability Centric Maintenance (RCM) organization can be achieved by progressing through a multi-year, three-phased effort of discovery, stabilization, and breakthrough.

Discovery

During the discovery phase the maintenance organization establishes benchmarks to assess current practices, performance measures, objectives, and prevailing attitudes.

Failing to establish current performance benchmarks dramatically increase the risk of a failed RCM implementation. Only measurable performance data can reveal if progress is being made, what areas are working well, and what areas need attention. Elements requiring analysis during the discovery phase are divided into physical, procedural, and technical areas.

Physical elements include:

Organization structure;

Prevailing attitudes;

Corporate culture;

Work methods;

Quality measures;

Mission effectiveness; and

Performance objectives and measures.

Procedural elements include:

Work and document control;

Maintenance prevention methods;

Training plans;

Major project scheduling and planning; and

Spare parts management.

Technical elements include use of:

Computerized Maintenance Management Systems (CMMS);

Predictive technologies;

Preventive and proactive maintenance tools;

Reactive maintenance cause and effect tools;

Technical training; and

Balance of maintenance strategies.

During the discovery phase, a maintenance vision is established that complements business-based performance measurements of quality, productivity, availability, reliability, and profit.

Stabilization

During the stabilization phase, two key activities must be achieved. First, maintenance activities must be transformed from reactive to planned and managed. Second, two core groups are established and trained. The first group provides maintenance planning and administration. The second group focuses on reliability improvement.

Maintenance-planning group responsibilities include:

Coordination of maintenance activities with production to obtain the least impact on availability;

Maintenance work planning, including procedures, tools, parts, inspections, and calibrations;

Coordination of minor housekeeping activities performed by operators;

Work order and cost tracking;

Establishment and updating of machine history files;

Coordination of preventive maintenance;

Evaluation of life cycle trends for possible machinery improvements; and

Spare parts management.

Elements of the maintenance planning group may exist in one form or another, but to achieve world-class level, focus must be moved from work-order generation and tracking to maintenance planning with goals of coordination and optimization.

Reliability improvement group responsibilities include:

Operate a self-directed maintenance team integrating all predictive maintenance technologies;

Provide timely component condition evaluations to maintenance planning, with the goal of eliminating unplanned downtime;

Perform ongoing system and equipment reliability prioritization analysis;

Implement proactive maintenance technologies and methods, including identification of recurring problems;

Track performance measures, e.g., savings from single event analysis, uptime/downtime, maintenance costs, quality, etc.;

Identify and eliminate unnecessary preventive maintenance activities;

Improve reliability by identifying needed equipment design changes;

Manage CMMSs; and

Analysis to determine and eliminate root cause failures.

The reliability improvement group’s first goal is to focus on implementing predictive technologies. As the group matures, the goal evolves into implementation of proactive strategies. Membership in this group includes machine mechanics and technicians chosen for their experience, abilities, and willingness to learn new techniques and tools. Initially the reliability improvement group includes at least three “expert” technicians in the technologies of infrared thermography, vibration, and lubrication analysis. As the group matures additional expert technicians trained in the areas of precision alignment, balancing, and root cause failure analysis are added.

Experience shows that as the number of “expert” technicians increase, total maintenance staff can shrink by 20% or more. Also, as the group matures and successes increase, attitudes aimed at the maintenance group improve; management begins to praise the elimination of unexpected breakdowns; chronic problems are eliminated; best practices are documented and shared; and performance measures shift from equipment events to asset utilization.

Breakthrough

Entry into the breakthrough phase may be subtle. Working as an operations focused unit, production, engineering, and maintenance are aggressively pursuing permanent elimination of breakdowns, identification and elimination of bottlenecks, and resolution of quality related problems to achieve nameplate (theoretical) production rates without scrap or rework.

The ultimate objective of many “up and coming” world-class companies is to enter and win recognition for excellence, such as The Malcolm Baldrige Award.

Similarly, maintenance organizations wishing to compare themselves with other maintenance organizations have an opportunity to enter their own international competition administered by CSI (Knoxville, Tenn.), a division of Emerson Electric. Through a series of questionnaires and on-site assessments the best-of-the-best are identified and receive international recognition for their efforts. Past winners include General Motors Truck Group (Arlington, Tex.), Allied Signal Corp. (Chesterfield, Va.), and E.I. Dupont (Cape Fear, N.C.).

Use of RCM techniques position maintenance as a strategic investment center within manufacturing—with a recognized and measurable impact on plant productivity and profitability—leading to a world-class organization.

A common element among current world-class maintenance organizations is effective use of maintenance software tools to plan, manage, prioritize, track, and report their performance.

Examine maintenance software

To obtain near real-time access to business information, companies have invested heavily in Enterprise Resource Planning (ERP) software and related consultants during the past several years. Among modules offered by most ERP providers is some form of enterprise asset management (EAM) software. EAM software is elevating the more traditional Computerized Maintenance Management System software into corporate prominence. EAM/CMMS solutions are being recognized as effective and efficient ways to increase ROI (return on investment) and lower total cost of ownership. While certain enterprise users will pay a premium to obtain the added sophistication offered in specialized EAM/CMMS solutions, others struggle to justify paying a second time for EAM software included in the original ERP suite.

Comprehensive EAM/CMMS software is available from companies such as Indus International (San Francisco, Calif.), PSDI (Bedford, Mass.), Datastream Systems (Greenville, S.C.), Mincom (Norcross, Ga.), JB Systems (Woodland Hills, Calif.), Walker’s Immpower (San Francisco, Calif.), and Fluor Daniel (Greenville, S.C.). But market dynamics and increasing competition from ERP providers challenges EAM/CMMS vendors to continuously incorporate new functionality, scalability, and platform choices to meet very specific customer requirements.

Advanced Manufacturing Research (AMR, Boston, Mass.) recently reported client/server deployments of EAM/CMMS software inched ahead of more traditional host-based implementations by 1% (31% and 30% respectively).

Interest in attracting smaller EMA/CMMS clients is evidenced by the software platforms available. For example, Datastream offers its MP2 EAM system for use on Access, SQL Server, and Oracle.

Fluor Daniel has taken another step to deliver MMS solutions to the very smallest companies by offering its TabWare CMMS software via the Internet. For a monthly per-user fee, (from a Java-enabled workstation, running client software) users have a full function CMMS solution without incurring the initial investment and on-going support expenses.

Integration with other ERP solutions is another area EAM/CMMS providers are working to satisfy customer requirements. For example, PSDI’s Maximo software is designed to integrate with SAP, Oracle, and PeopleSoft ERP applications and also with CSI’s (Knoxville, Tenn.) Reliability Based Maintenance (RBM) solution suite.

Even companies serving the same markets do not run their businesses alike, nor require the same functionality from their ERP/EAM/CMMS solutions. That is why every solution provider offers a variety of modules.

Nearer the plant floor, companies like Honeywell (Phoenix, Ariz.), and Fisher-Rosemount (Minneapolis, Minn.) offer software, services, and embedded technologies to assist in managing assets and implementing preventive maintenance. Honeywell’s suite of @sset.MAX solutions is designed to protect people, plant, and equipment. For example, control center design, equipment health management, alarm management, and loop scout are among Honeywell’s solution suite.

Fisher-Rosemount’s Asset Management Solution SNAP-ON permits calibrators, such as Fluke’s 702, Druck’s TRXII, and Rosemount’s T460, to perform online configuration, testing, and diagnostics of HART compatible devices.

Additionally, very specialized tool sets are available to enhance reliability and maintenance efforts. For example, using web-enabled technologies, PlantQue from PlantWare (Appleton, Wis.) communicates directly with automation controllers to collect real time, “rules based” machine, operator, and product performance data and organize data into efficiency and production reports.

When repairs are necessary, timely access to the correct documentation is critical to minimizing downtime. iKnowldedge’s (Lexington, Mass.) interactive, multimedia PerformanceWare application provides maintenance personnel with electronic access to troubleshooting and maintenance knowledge, including notes and comments recorded during previous maintenance efforts.

When attempting to find event root cause, TapRooT software from Systems Improvements (Knoxville, Tenn.) guides users through the process, analyzes the results, and assists in developing permanent elimination solutions.

World-class means different things to different people, but common elements within world-class manufacturing enterprises include the use of software tools and an environment where production, engineering, and maintenance perform as a unit for the good of the enterprise and its customers.

Improving asset performance

Operating a fleet of 400 stationary engine-compressor sets for natural gas production, a multi-national company needed to reduce operating costs and increase asset availability and reliability.

Selecting a side-by-side pair of Worthington two stage, four throw compressors each driven by Waukesha 1,500 hp turbo charged natural gas engines, one engine-compressor set was retrofitted with Spartan Control’s (Calgary, Alberta, Canada) REMVue Dynamics Machine Management System. Three key objectives were established as success criteria for side-by-side evaluation.

Improve fuel economy;

Reduce CO and NOx emissions;

Increase unit availability.

REMVue is a computer based data acquisition, performance monitoring and control system. Using a touch screen interface, users view engine and compressor data and interface with the REMVue engine control algorithm. In addition to flow, pressure, and temperature control capabilities, REMVue measures and archives machine condition and performance metrics including vibration, cylinder pressures, and calculated operating efficiency. Archived data is used to monitor equipment condition, update maintenance management applications, and optimize natural gas production operations.

To permit the REMVue system to monitor and control the test engine-compressor set, the mechanical/hydraulic governor system and fuel gas regulators were replaced with a pneumatic actuator, two control valves equipped with Fisher-Rosemount’s Field-vue valve controllers, and a flow meter.

During the first eight months of operation the REMVue fitted engine-compressor set experienced a:

16.7% ($45,000) reduction in fuel consumption;

96.7% reduction in average CO emissions;

80.7% decrease in average NOx emissions;

120 F decline in average exhaust temperature;

Improved in engine manifold pressure balance;

Reduced in noise and vibration; and

Improved in availability/reliability.

Testing is on going, but initial indications that engine-compressor set asset performance and availability can be substantially improved are encouraging.

For more information on REMVue Dynamics, visit