Although conference and trade show attendance has been off recently, a couple of user group conferences in which I've been able to participate have bucked the trend. Perhaps it is because the condition assessment technology vendors sponsoring these particular events do such a good job facilitating the exchange of information.

I heard a number of great presentations on how organizations are leveraging various maintenance technologies. Here are two examples:

A government laboratory where operating funds are being reduced 10 percent a year over a 4-year period is using condition-based maintenance to help compensate for the loss of funding. It is an appropriate strategy for attacking maintenance costs while supporting availability of research equipment.

A processing company increased its competitive position by a proactive maintenance process that includes a precision alignment policy that specifies alignment targets and tolerances for critical machinery. After a jump in the first year when the policy was initiated, maintenance costs have declined steadily because there are fewer failures and the length of time between scheduled maintenance has increased. Meanwhile, product unit costs have declined steadily because of increased equipment capacity and availability.

However, amongst the many success stories, there was considerable conversation about the difficulty in obtaining resources for condition assessment operations, about the precipitous decline in reliability and maintenance capability in many organizations, and even about plants that are sliding back into the morass of reactive maintenance.

What is going on? While conference attendees are pushing forward with condition assessment technologies and reaping the benefits of proactive maintenance, they often receive increasing pushback from upper management. Proactive maintenance is not an extravagance. It is a value-adding function that produces plant capacity. What's the matter with these managers? Evidently, they just don't get it.

I always thought a responsible manager of a business should endeavor to protect the value of the company's equipment and insure that it is available to meet market demand. It has been said that rational people consider the consequences of their actions. If so, there must be a reason why so many managers are destroying their company's reliability and maintenance capability. What is it? Now, I don't get it. Can anyone explain it to me? MT

There are those pundits who say that the maintenance industry has dealt with technological change successfully for years and has readily adapted in the past. But what has changed is the pace with which the technological influx has forced itself into the offices of maintenance managers.

Upper management often has dictated technological advances, as have other back-office operations seeking data integration opportunities. The technological tools that are available for the typical maintenance operation are multiplying like rabbits.

In the past, the old corps of maintenance managers turned to cross training as the way to put their fingers in the proverbial dike of technology. It used to be simple: take one maintenance staffer who was proficient with computers and send him off for a one-week class so he could master the new software or tool. It worked & sometimes.

What is changing is the level and degree of expertise and experience that is required to support a more sophisticated suite of integrated software applications. This is not an issue that maintenance managers can prevent with stopgap training. This is going to require the hiring of personnel that have the competencies to allow a maintenance department to readily adapt and assimilate the influx of technologies that affect all aspects of maintenance.

The competencies that are going to become more prevalent in maintenance departments in the next few years are database administration, system implementation, and technology education.

Database administration
Data warehousing--the use of a central repository for corporate data--as well as the influx of high-end databases in maintenance applications (Oracle, Sybase, etc.) have created a demand in many maintenance organizations for a database administrator. This is not simply database backup, but keeping maintenance databases optimized--fine-tuned and fully integrated with other applications.

In some organizations this competency is handled by someone in information services or data processing, but in decentralized companies, it often falls to the maintenance department to supply its own personnel. Individuals with this competency may have undergone years of training on the database(s) they know as well as years of experience.

The database engines of today are a far cry from the CMMS that Earl wrote in dBase II on his home computer--and are integrated with far more applications. Moreover, today's database management skills come with a price that is staggering to many maintenance department compensation budgets.

System implementation
Understanding technology is important; being able to implement it requires a different competency. Individuals possessing these skills have to know and understand the entire scope of the maintenance business.

At the same time they have to have a full understanding of technology and its impact. Their job, on an on-going basis, is to integrate the two. They must understand how to change processes to take advantage of the technology, while at the same time know how to fine-tune the technology to work for the business.

Technology education
The tools for maintenance work have become more complicated and have a number of prerequisite skills in regards to computers. There is a need to have individuals that possess the skills necessary to educate others on the technology. They have to have a background understanding of maintenance processes, while at the same time be able to translate the technology to the average maintenance worker.

While the competencies are important, they do not necessarily have to reflect in a staffing model. Some of these skills, particularly those in implementation and education, can be outsourced. The key, obviously, is to get a technology consultant with a background in maintenance operations--which is a narrow field to begin with. A strong database administrator, however, is something that is necessary for the survival of some systems (depending on their complexity) and is a position that is increasingly being served by full-time staff rather than outsourcing. MT

Blaine Pardoe is a principle in Enterprise Management Systems and a highly regarded expert in the field of technology learning, CMMS implmenetation, and the maintenance in-dustry. He is the author of the best-selling book, Cubicle Warfare, and numerous novels and is a frequent contributor to Maintenance Technology.

Compressed air is a critical power resource in most manufacturing and process environments. It constitutes from 7-40 percent of the total electrical use in most plants. If the pressure drops below an acceptable level, production is interrupted. If the contaminant level of the compressed air varies significantly in terms of moisture, lubricant, or dirt, production quality is affected.

In terms of wire to work, it represents the most inefficient means of transmitting power in the plant. A relatively well-designed compressed air system with little waste will produce approximately 11 percent of the input energy in the form of work at the point of use. At 6 cents per kWh, 3 shifts a day, 7 days a week, every 100 cfm costs approximately $15,000 per year; 1000 cfm can cost more than $150,000 per year. If a plant produces 10 percent pretax profit, it must generate $1.5 million in production revenue to support 1000 cfm of average use per year. Despite this information, well-intentioned production personnel give little thought to the use of compressed air.

Most manufacturing facilities have no idea how much compressed air they actually use or need. At best, they may know the minimum acceptable pressure and air quality required through experience. This information probably has been handed down from previous operating personnel.

There is probably a significant fudge factor between perception and reality. It is highly unlikely that anyone knows specifically what the compressed air costs, and there are no rules for its use on the production side of the system. Production installs new compressed air usage on a regular basis with no discussion with facilities personnel and no idea what impact this change may have on other production applications, system reliability, or system operating cost. In the average facility, this expensive and critical utility is used as though it is a limitless resource.

Fig. 1. Operating Approach: Good business practices should be followed when operating a compressed air system. By investigating the source of a problem, companies can avoid buying a $100,000 compressor to solve a problem that can be corrected by replacing a $10 filter.

• Production can use air any way it chooses with no communications or accountability. All problems on the production side of the system will be corrected on the supply side of the system with no problem definition. All problems should be interpreted as insufficient supply or treatment. If leaks or inappropriate use become excessive, without definition or investigation, facilities personnel are expected to increase the supply of compressed air to more than correct the results of the situation (see Fig. 1). One would liken this approach to jacking up the taps on the substation to correct ground faults in the electric distribution system.
• If production is unhappy and wants more compressors or cleanup equipment to correct any poorly defined symptom that shows up in production, money will be appropriated immediately with no consideration for the impact on operating costs and no justification required. On the other hand, if the same problem can be corrected by applying production needs differently, or the system can be retrofitted to lower operating costs to correct the problem, stringent return on investment requirements must be met for dollars spent. Even if these financial hurdles can be met, there will be a competition with production for capital. In most facilities, competing with production for anything is typically a losing exercise. All of this occurs while management is demanding a reduction in the facility's operating budget.
• After surviving these unwritten rules for any period of time, facilities personnel and maintenance management simplify the operating protocol as follows: Do whatever it takes in operating the compressed air system so that they won't call. The telephone becomes the instrument of choice to validate performance. If they don't call, life is good. No reasonable manager can look at this typical operating situation and believe that it makes any sense. Part of the problem is that plant management has never seen this perspective in its entirety. In every instance where production has been exposed to this information quantitatively, appropriate assignment of responsibility is corrected. Even production management cannot condone this approach when faced with the financial and qualitative results.

Fig. 2. Generating Transparancy: Control storage allows for 14 psi of pressure drop with no change in demand psig. The capacitance of control storage should be equivalent to the largest event for the allowable pressure drop for the time required to get the next available compressor to support the transient change in demand. Supply changes to adapt to demand without any change in demand pressure. In most systems, supply energy is relatively constant with demand changing in pressure and air quality constantly.

Five years ago, a concerned consortium of users and utilities asked that a number of quantitative system audits be combined to determine a typical situation. In an analysis of 42 systems which were audited, on average less than 50 percent of the total compressed air produced in the facilities contributed to productivity. The Average constituents of demand for compressed air systems in 42 surveyed plants table represents the constituents of demand that were found in these compressed air systems on the average.

There were many uses that fell into the inappropriate user category other than those listed, including vacuum generators, sparging, aspirating, vibrating, and atomizing liquid. All of these uses could be accomplished more effectively using an alternative form of power such as vacuum, mechanical pumps, or blowers.

Artificial demand is the volume of air that is generated by operating users at higher pressures than necessary to achieve the desired results. It also would be described as the volumetric difference between the volume at the actual pressure and the volume that would be consumed at the lowest acceptable operating pressure.

The open blowing applications were primarily applications that could have been better applied with blowers. At the least they should have been applied with high-efficiency nozzles or amplifiers. The bulk of these applications were for wiping, item cooling, personnel cooling, and parts or scrap ejection.

Drainage was represented primarily by solenoid or motorized valves that discharged more air than effluent. There were also many cracked bypass valves and direct open blowing. Despite the fact that the percentage of volume was relatively small, the impact these drains had on the systems was quite significant. In a majority of cases, although the volume was small, the rate of flow coupled with the systems' capacitance caused sufficient momentary pressure drops that prevented at least one compressor from unloading or timing out in the systems.

Dryer purge represented such a low average percentage because few of the systems had desiccant dryers. Of those that had these dryers, only a small percentage were air-reactivated or heatless. Where heatless dryers were in use, the impact on the system was significant not only relative to volume, but also to event pressure drops that occur on the tower switchover.

There were only five systems where nozzle wear or attrition applied. The applications included wear on air jet looms in textile plants and nozzle inserts on sandblasting equipment. Slight increases in nozzle size can increase the air consumption appreciably.

Financial considerations
What impact does compressed air have on the bottom line?

The systems that were audited in the analysis were larger systems averaging 1760 kW of onboard power including compressors, dryers, pumps, and fans. The average compressed air use was 8130 cfm at 103 psig. The average cost of electricity was 4.8 cents per kWh. The average hourly use per year was 7760 hours. The average annual cost for electricity was $655,564.80.

The cost of makeup water, water treatment, operator labor, maintenance, outside labor, parts inventory cost, depreciation, insurance, property tax, administration, and supervisory cost added an average of $375,825.40 per year to the electrical cost. The total annual operating costs averaged $1,031,390.20.

Consistently, the individual plants did not know what their compressed air costs were. Those that speculated underestimated typically by more than 50 percent. Reasonable business decisions cannot be made when financial consequences cannot be accurately determined.

If the total cost is divided by the operating hours per year, the result is $132.91 per hour. When the cost per hour is divided by the units of 100 cfm, the result is $132.91 divided by 81.30 units or $1.63 per 100 cfm per hour of operation. This unit value for compressed air allows production to estimate the operating cost of an application and evaluate the best alternatives.

The average quantity of leaks (18 percent) multiplied by the total average volume of 8130 cfm is 1463 cfm. Multiplying the unit cost of $1.63 by 14.63 units results in an hourly cost of $23.85 for leaks. Multiplying this figure by the hours of service results in an annual cost of $185,052 for leaks.

If production applies a 1/4 in. open nozzle at 90 psig to dry or wipe a wet article somewhere in the production process, it would consume 94 cfm. These units of air times the hourly cost of $1.63 times 7760 hours per year generates an estimated annual operating cost of $11,890.

The same function can be performed with a 1/2 hp positive displacement blower. The open blow nozzle costs nothing to apply compared to perhaps $750 for the blower and installation. The annual cost of operation for the blower would be $150.20. The question is whether a little extra effort and up to $750 in expense is worth more than $10,000 in operating cost. The answer should be obvious, but it is not unless there is a clear understanding of unit cost, accountability for operating cost, and a mandate from management to treat the use of compressed air as a business decision.

The use and installation of all other utilities is carefully applied and reviewed. This is primarily because of code and operating personnel who understand both the financial and operational consequences of poor applications. It is interesting that a $10,000 business decision in most plants requires several signatures, yet anyone in production can make such a decision with no discussion at all. Sound accounting principles need to be used to get management to show an interest in opportunities and issues.

Quality
Is compressed air measured as an assigned or unassigned cause as it impacts production quality?

There are a number of causes for poor quality compressed air. The most prevalent is the least obvious; when one intermittent application with a high rate of flow causes a critical use to experience a drop in pressure. The cause of the problem is seldom determined. Instead, the effect is treated. The normal diagnosis is insufficient supply.

Chances are the system is operated at a sufficiently high supply pressure that when the event occurs, the pressure does not drop for the critical use. The size of the additional compressor operating to compensate will determine the degree of pressure fluctuations that occur. The result is a lack of repeatability at the point of use at an unnecessarily high operating cost.

The most significant problem of forcing the system to work with power is inconsistency. The best operating approach is to control the demand air density at variable mass independently of the supply system. This allows clean air to be stored on the upstream side of the demand control to support the transient events instantaneously and demand at the lowest pressure can be regulated all of the time. By controlling demand independently, supply can be operated at the best independent pressure so compressor performance can be optimized. The result is accuracy at the lowest required pressure and optimum supply performance at or near the isothermal design of the compressors' point of use quality at the best operating efficiency (see Fig. 2).

Leaks, dirty point-of-use filters, and increased air flow across installation components all cause the article pressure to drop on production equipment. Since differential pressure increases as a square function of flow increase, even a small leak can cause the pressure to drop and affect quality. Point-of-use filters are seldom monitored for dirt loading or cartridge change. In fact, most plants have no point-of-use filter cartridges in inventory.

In the absence of measurement, erratic operation of equipment would imply that the filter might need service or that a leak test should be performed. Unfortunately, the problem is normally diagnosed as insufficient supply energy. When the point-of-use regulator can no longer be increased, a telephone call is made to the compressor room operator.

Another problem occurs when applications increase the cycles per minute or the rate of flow is increased. Both situations require resizing some or all of the installation components so there will not be a decrease in point-of-use pressure. If production anticipates increasing cycles, rate of production, or air consumption, the installation needs to be reevaluated.

Contamination in the system is another problem that causes poor quality. To maintain the cleanup system:

• Size the filtration and drying equipment for the heat load and mass flow at density.
• Maintain a consistent temperature into the equipment within the design parameters.
• Design and maintain a superior drainage system. Do not cut corners.
• Store enough clean, dry air on the downstream side of the cleanup equipment to support transient events in demand without generating a velocity across the cleanup equipment.
• Control the water flow and temperature across all heat exchangers.
• Provide adequate monitoring equipment to observe process results. Benchmark and trend approach temperatures relative to ambient and cooling temperatures. The equipment will eventually foul and fail; the system does not have to if a predictive maintenance approach is taken.

The most critical component of air quality is the temperature of the air at various control points. A 10 deg rise in temperature can alter the cleanup equipment performance by 26 percent.

Reliability
Is a risk management plan in place to prevent production downtime with compressed air?

Most concerned buyers of compressed air equipment attempt to differentiate equipment based on how it may influence the reliability of the system. There is no perfect piece of equipment. This is rotating equipment; it will fail. The premature failure will likely be a result of how the system is operated and the equipment in it. It is more important to find out the shortcomings of the equipment and how it fails. Armed with this information, equipment can be selected and the system designed to control risk and minimize downtime. Other basic actions that will improve the reliability of the system include:

• Select compressors that are not so large in relation to the total demand that the failure of one of them can cause the system to fail.
• Write a failure scenario in a supply, demand, pressure, storage, and time algorithm. Request and test the permissive response time to start all compressors from a cold start to full load with the motor and the compressor off. Measure the capacitive storage of the system expressed in cubic feet per psig. This information is essential to automatically back up the failure of a compressor or an unusually large demand event without achieving an unacceptably low pressure.
• Choose smaller, faster, more automation-friendly compressors that will support risk more effectively than larger, slower units that back up other large units.
• Provide as much parallel individual compression and cleanup equipment as possible, so that if a compressor or piece of cleanup equipment fails, the entire train of equipment is not lost. Too many systems are designed with a number of parallel trains with a compressor, aftercooler, filter, and dryer. You can have one compressor from one train and a dryer from another train down for service and lose both trains from service.
• Trend and benchmark all system variables and deltas against design performance. Maintenance can be anticipated in advance of failure. If the system is large or critical, a central management information system may be necessary.
• Develop a failure plan for the demand side of the system. In the event of a supply side equipment failure, manually or automatically limit the least important use sector so that the required pressure holds in the balance of the system. If the demand usage by sector is prioritized, the least important to the most important can be automatically limited or adjusted until the system is stable. The greatest risk of interruption will be when three or fewer compressors are on line and there is no demand side risk management program.

Compressed air is the most poorly designed and managed of all industrial utilities. It provides a great opportunity to improve productivity while reducing operating cost. Compressed air systems include the supply, the demand, and the in between. If production use is treated as a black hole that must be satisfied at any cost, the bounds of reason have been violated. Costs will skyrocket while performance declines. With the current demands from management for more effective use of assets, compressed air certainly can be categorized as low-hanging fruit. MT

This article is based on a paper presented during National Manufacturing Week, March 18, 1999, in Chicago, IL.

R. Scot Foss is president, Plant Air Technology, P.O. Box 470467, Charlotte, NC 28277; telephone (704) 844-6666; e-mail airsagas@aol.com; Internet www.plantair.com

In February 1999, a technical committee sponsored by the International Society of Automotive Engineers (SAE) completed a draft standard for Reliability-Centered Maintenance (RCM), for use by anyone who wishes to apply RCM to their physical assets. The draft SAE standard provides criteria that can be used to evaluate proposed maintenance-program-development processes and determine whether they are RCM processes. SAE approval is expected by September 30, 1999.

RCM is one of several processes developed during the 1960s and 1970s, in various industries, in order to help people determine the best policies for managing the functions of physical assets, and for managing the consequences of their failures. Of these processes, RCM is the most thorough.

An RCM process systematically identifies all of the asset's functions and functional failures, and identifies all of its reasonably likely failure modes (or failure causes). It then proceeds to identify the effects of these likely failure modes, and to identify in what way those effects matter. Once it has gathered this information, the RCM process then selects the most appropriate asset management policy.

Unlike some other maintenance development processes, RCM considers all asset management options: on-condition task, scheduled restoration task, scheduled discard task, failure-finding task, and one-time change (to hardware design, operating procedures, personnel training, or other aspects of the asset outside the strict world of maintenance).

Development of the standard
When the SAE group began working, it thought in the same terms as most others; it thought that an RCM standard had to prescribe a standard RCM process. Therefore it began to work on developing such a process. This was difficult, because different members of the group were already using different processes as they performed RCM. The first members of the group had to work together for about a year of occasional meetings before they developed enough respect for each other's expertise to allow them to listen to one another without rejecting each other's proposals outright. It took another year before they began to agree on a common process that might be called a standard RCM process.

Informal feedback from the RCM community showed that people outside the committee were unaware of the careful compromises in the first draft, and they saw no need for such compromises. It appeared that the effort to develop a standard process was likely to produce only another process, which would be added to the processes already competing for the RCM name. It took another half-year to realize that there was another way.

The current draft standard being considered by the SAE does not present a standard RCM process. Its title is Evaluation Criteria for Reliability-Centered Maintenance (RCM) Processes. This standard presents criteria against which a process may be compared. If the process meets the criteria, the standard's user may confidently call it an RCM process. If it does not, the user probably will not call it an RCM process.

The draft standard is not a large document. Including foreword, glossary, and bibliography, it contains only about 4000 words. After the introduction, it begins with the basic statement of the seven RCM questions noted in the accompanying section Essential Elements of RCM.

The last sentence in the essential elements section represents an important concept: any process that conforms to this standard will make the information and the decisions fully available to and acceptable to the owner or user of the asset. Since the goal of maintenance is to ensure that a physical asset continues to do what its owner or user wants it to do, every RCM process must ensure that the desires of the owner or user are made an integral part of the maintenance development process. It is not enough for the vendor simply to hand owners or users a maintenance program, without asking owners or users what they wish the asset to do for them, not if the vendor is going to develop the maintenance program using RCM.

Each of the seven RCM questions is then supported with specific criteria that ensure that the process under evaluation answers the question satisfactorily.

Question 1: Functions
What are the functions and associated desired standards of performance of the asset in its present operating context (functions)? The specific criteria that the process must satisfy are:
• The operating context of the asset shall be defined.
• All the functions of the asset/system shall be identified (all primary and secondary functions, including the functions of all protective devices).
• All function statements shall contain a verb, an object, and a performance standard (quantified in every case where this can be done).
• Performance standards incorporated in function statements shall be the level of performance desired by the owner or user of the asset/system in its operating context.

The operating context is what it says: the context in which the asset is operated. The same hardware does not always require the same failure management policy in all installations. For example, a single pump in a system will usually need a different failure management policy from a pump that is one of several redundant units in a system. A pump moving corrosive fluids will usually need a different policy from a pump moving benign fluids.

Protective devices are often overlooked; an RCM process shall ensure that their functions are identified.

Finally, the owner or user shall dictate the level of performance that the maintenance program shall be designed to sustain. Once again, this key RCM characteristic is part of the evaluation criteria provided by the SAE standard.

Question 2: Functional failures
In what ways can it fail to fulfil its functions (functional failures)? This question has only one specific criterion: All the failed states associated with each function shall be identified.

If functions are well defined, listing functional failures is relatively easy. For example, if a function is to keep system temperature between 50 C and 70 C, then functional failures might be: Unable to raise system temperature above ambient, unable to keep system temperature above 50 C, or unable to keep system temperature below 70 C.

Question 3: Failure modes
What causes each functional failure (failure modes)? In Failure Modes, Effects and Criticality Analysis (FMECA), the term failure mode is used in the way that RCM uses the term functional failure. However, the RCM community uses the term failure mode to refer to the event that causes functional failure, so the SAE standard uses the term in this way as well. The standard's criteria for a process that identifies failure modes are:
• All failure modes reasonably likely to cause each functional failure shall be identified.
• The method used to decide what constitutes a “reasonably likely” failure mode shall be acceptable to the owner or user of the asset.
• Failure modes shall be identified at a level of causation that makes it possible to identify an appropriate failure management policy.
• Lists of failure modes shall include failure modes that have happened before, failure modes that are currently being prevented by existing maintenance programs, and failure modes that have not yet happened but that are thought to be reasonably likely (credible) in the operating context.
• Lists of failure modes should include any event or process that is likely to cause a functional failure, including deterioration, human error whether caused by operators or maintainers, and design defects.

RCM is the most thorough of the analytic processes that develop maintenance programs and manage physical assets. It is therefore appropriate for RCM to identify every reasonably likely failure mode. While reasonably likely is obviously not subject to a strict and rigorous definition, it is possible to name some of the things that are expected to be included within itcertain things that some processes explicitly exclude from their analysis.

For example, some processes explicitly exclude failure modes already addressed by the existing maintenance program. An RCM process will examine these failure modes, in order to decide whether existing maintenance practices are truly the best way to manage those failure modes.

Another thing that an RCM process will include is failure modes that have not yet happened, but that are thought to be reasonably likely (credible) in the operating context. Some analytic processes look only at failure histories, not attempting to foresee problems that have not yet been encountered. In retrospect, it is often said of many industrial accidents that they were simply waiting to happen, that it was only a matter of time before the site's unsafe but customary practices arranged themselves in a sequence that led to disaster. Before that disaster, the failure mode had never appeared in the site's failure history.

Finally, an RCM process will not restrict itself to engineering processes such as deterioration. Human error (especially from lack of training) and design defects lead to many failures as well, and in many industrial sites no one looks at these topics in an organized way.

The standard recognizes that some organizations, especially very large organizations such as the U.S. military, distribute responsibilities for these topics in different offices and may be reluctant to put all of those responsibilities under an RCM program office. The process being evaluated is intended to be the process that the entire organization uses, not simply one office within the organization. If the organization's process satisfies these criteria, then the organization has satisfied this element of an RCM process.

Question 4: Failure effects
What happens when each of the failures occur (failure effects)? The standard's criteria for a process that identifies failure effects are:
• Failure effects shall describe what would happen if no specific task is done to anticipate, prevent, or detect the failure.
• Failure effects include all the information needed to support the evaluation of the consequences of the failure, such as: (a) What evidence (if any) that the failure has occurred (in the case of hidden functions, what would happen if a multiple failure occurred); (b) What it does (if anything) to kill or injure someone, or to have an adverse effect on the environment; (c) What it does (if anything) to have an adverse effect on production or operations; (d) What physical damage (if any) is caused by the failure; and (e) What (if anything) must be done to restore the function of the system after the failure.

FMECA usually describes failure effects in terms of the effects at the local level, at the subsystem level, and at the system level. This reflects its origins in the U.S. military, which assigns each component a place in a functional hierarchy. Some RCM processes follow FMECA's example here. A process that follows this three-part format can satisfy the SAE criteria, so long as the information above is provided.

Some people may stumble over the last element of information: what (if anything) must be done to restore the function of the system after the failure. They may feel that this brings corrective maintenance into the RCM analysis. Actually, this is information that someone will have to gather at some point, in order to compare the costs of maintenance versus the costs of the failure. Practical experience with RCM has found that this is the most convenient point at which to gather (and record) that information.

Question 5: Failure consequences
In what way does each failure matter (failure consequences)? The standard's criteria for a process that identifies failure consequences are:

• The assessment of failure consequences shall be carried out as if no specific task is currently being done to anticipate, prevent, or detect the failure.

• The consequences of every failure mode shall be formally categorized as follows:
  • The consequence categorization process shall separate hidden failure modes from evident failure modes.
  • The consequence categorization process shall clearly distinguish events (failure modes and multiple failures) that have safety and/or environmental consequences from those that only have economic consequences (operational and nonoperational consequences).

RCM assesses failure consequences as if nothing is being done about it. Some people are tempted to say, Oh, that failure doesn't matter because we always do (something), which protects us from it. However, RCM is thorough. It checks the assumption that this action that we always do actually does protect them from it, and it checks the assumption that this action is worth the effort.

RCM assesses failure consequences by formally assigning each failure mode into one of four categories: hidden, evident safety/environmental, evident operational, and evident non-operational. The explicit distinction between hidden and evident failures, performed at the outset of consequence assessment, is one of the characteristics that most clearly distinguishes RCM, as defined by Stan Nowlan and Howard Heap, from MSG-2 and earlier U.S. civil aviation processes.

The SAE's criteria add an element to Nowlan and Heap's categories. In 1978, people were far less conscious of the environment than they are today. The consequences of harming the environment were chiefly economic, in terms of fines and fees that many firms felt they could afford.

Then, in the 1980s, the world experienced a string of industrial accidents with serious effects on the environment, such as Chernobyl and Exxon Valdez. Governments increased the severity of their punishments for environmental accidents. Today in some cases an environmental accident may cause a plant to be shut down completely, and its owners or users may be subject to prison terms. To harm the environment is becoming as dangerous to the organization, in business terms, as it is to harm people directly. Environmental consequences are becoming as important as safety consequences.

Question 6: Proactive tasks
What should be done to predict or prevent each failure (proactive tasks and task intervals)? This is a complex topic, and so its criteria are presented in two groups. The first group pertains to the overall topic of selecting failure management policies. The second group of criteria pertains to scheduled tasks and intervals.

The standard requires a process that selects failure management policies to work as if nothing is currently being done about the failure, and to make no assumptions about the presence or absence of wearout. It also requires the process to select scheduled tasks only if they are techically feasible and are worth doing.

With respect to scheduled tasks and their intervals, the standard describes in detail what criteria an RCM process must use to determine whether a task and its interval are technically feasible and worth doing.

Details about all these criteria will be covered in a subsequent article.

Question 7: Default actions
What should be done if a suitable proactive task cannot be found (default actions)? This question pertains to one kind of scheduled task (failure-finding), as well as unscheduled failure management policies: the decision to let an asset run to failure, and the decision to change something about the asset's operating context (such as its design or the way it is operated). Once again, the standard describes in detail what criteria an RCM process must use to determine whether a failure-finding task is technically feasible and worth doing, and whether an unscheduled failure management policy may be selected.

The full set of criteria will be discussed in a subsequent article along with further discussion of selecting proactive tasks.

It is at this point, after selecting proactive tasks and default actions, that most RCM processes usually end. The SAE standard continues briefly.

Two remaining issues
The first issue has to do with the fate of the analysis after the process has run its course. The SAE standard recognizes that (1) much of the data used in the initial analysis are inherently imprecise, and that more precise data will become available in time, (2) the way in which the asset is used, together with associated performance expectations, will also change with time, and (3) maintenance technology continues to evolve. Thus a periodic review is necessary if the RCM-derived asset management program is to ensure that the assets continue to fulfill the current functional expectations of their owners and users.

Therefore, the standard continues, any RCM process shall provide for a periodic review of both the information used to support the decisions and the decisions themselves. The process used to conduct such a review shall insure that all seven RCM questions continue to be answered satisfactorily and in a manner consistent with criteria set out for each in the standard.

The second issue has to do with mathematical and statistical formulae used while applying the processespecially those used to compute task intervals. Some processes offered by some vendors use mathematical algorithms that apply the methods appropriate to scheduled restoration or discard tasks when they compute task intervals for on-condition tasks. Some vendors use complex algorithms that are not easily explained, and then bury them in computer software without offering a coherent account of the mathematics involved.

The SAE standard contains this requirement regarding such formulae: Any mathematical and statistical formulae that are used in the application of the process (especially those used to compute the intervals of any tasks) shall be logically robust, and shall be available to and approved by the owner or user of the asset.

Issues not included
We have seen what is in the SAE standard. What is equally worth noting is what is not in the SAE standard.

First, the SAE standard has no decision-logic diagram. This is deliberate. Different members of the RCM community use different decision-logic diagrams. It seemed not only difficult but also unnecessary to require an RCM process to use only one diagram, since it was possible to give general requirements for tasks that were technically feasible and worth doing without using a diagram.

Second, the standard does not dictate how to organize the RCM analysis. This too is deliberate. Within the RCM community, there are different opinions about the best way to organize the work of an RCM analysis. Some say that the analysis is best performed by a single RCM expert, supplemented by technical information about the asset from local experts, while others say that the analysis is best performed in groups, by local experts who are trained in RCM.

Further, some say that the RCM analysis should be performed by expert consultants (usually a single expert), while others say that the analysis should be performed by trained employees of the organization (either a single analyst or a group). As an intermediate position, some say that a consultant should lead a group of trained employees.

The SAE standard does not prescribe such matters. It is restricted to evaluating possible RCM processes, and does not evaluate ways to use an RCM process.

Third, the SAE standard does not address the question of which assets should be subjected to the process. This question lies outside the scope of the RCM process itself, and is a matter for the owner or user of the asset to decide.

In practice, some owners/users decide to apply RCM to all their assets. Others decide to apply RCM only to their most critical units. Some who decide to apply RCM to all their assets decide to do so as quickly as possible. Others decide to apply RCM to all their assets more slowly.

All of these decisions are made on business grounds, based on weighing the expected costs of the process against its expected benefits. None of these decisions has any bearing on the validity of the process that is applied. Since this standard addresses only the process itself, it therefore remains silent on this decision.

Using the standard
Now that we have seen the standard, how would it be used?

The SAE standard is expected to be used by organizations that want to receive the benefits of RCM and that wish to insure that the process they use is indeed an RCM process.

Some organizations may already be using a process, and may wish to see whether it is an RCM process. The SAE standard helps them do this. If it is not, they may wish to consider whether the benefits they are obtaining from their non-RCM process justify their efforts to use it. If they conclude that the process works and is worth doing, they are free of course to continue to use it. However, if they do wish to use RCM, now they will know that they need to begin using a different process--either in place of, or as well as, their existing process.

Organizations that do not already have RCM in place may want help from those who offer to use or teach RCM. The standard is voluntary; no one requires an organization to use it to evaluate RCM processes. However, an organization that chooses to use the SAE standard is free to reject those whose processes do not meet the standard's criteria, just as a company is free to reject vendors whose processes do not meet the criteria of other noncompulsory industry standards, such as SAE's automotive FMECA standard.

An organization that uses this standard may find itself evaluating a number of firms that offer RCM services. Of those firms, it is possible that more than one firm may have processes that satisfy the criteria in this standard.

Once these surviving processes have been identified--once it is clear that these firms are offering RCM processes--the evaluating organization will then need to choose among them. It is expected that the organization will make its final decision on business grounds: for example, by examining which firm seems best-equipped to provide appropriate services by an appropriate date, which firm has the most appropriate price, and so forth. Issues such as the way in which RCM is organized and which assets should receive RCM, discussed previously, will emerge in the course of these business decisions, and this SAE standard is not intended to evaluate those decisions.

Thanks in part to its carefully restricted scope, the standard was completed only 8 months after its first draft was presented to the SAE RCM subcommittee. In February 1999, the final draft was submitted to the SAE's Supportability Committee for balloting. Once any necessary changes have been made and approved, the draft then will be submitted to the SAE's Technical Standards Council for balloting. If all goes well, the standard should be approved by the SAE in September 1999.

The SAE standard for RCM is expected to help those who wish to apply RCM as they evaluate their own processes, or the processes proposed by vendors and consultants. By using the standard, organizations will be able to determine which processes are RCM processes, and which are not. MT

(Proactive tasks and default actions, Questions 6 and 7, are discussed at length in "RCM Tasks.")

Dana Netherton is chairman of the SAE's RCM subcommittee, and a principal of American Management Systems, Inc. (AMS), Fairfax, VA. He has been working in the field of RCM since 1989, chiefly with surface ships in the U.S. Navy. Before joining AMS, he served in the U.S. Navy for 10 years as an officer in nuclear submarines. He can be contacted by e-mail netherto@cais.com.

In early 1997, Rick Marzec, director, medical center engineering, and Greg Kozlik, manager, mechanical services and engineering technology, at Rush began seeking a way to cut maintenance costs while increasing the productivity of technicians through the deployment of a computerized maintenance management system. They selected MAXIMO from PSDI, Bedford, MA, to control and manage their maintenance processes.

Like most maintenance organizations that use a CMMS, Rush was principally paper based. Marzec and Kozlik knew that the value of the software investment was a function of the quality and quantity of data that it housed. Faced with either staffing data entry personnel or training its tradespeople to divert wrench time to do their own data entry, Rush sought a solution to its data collection problem.

Our technicians were losing almost 2 hours a day picking up, handing off, and completing paperwork, Kozlik said. In fact, technicians had to stop accepting work 40 minutes before the end of their shift, simply so they could complete their paperwork. Multiply that 40 minutes by our 85 technicians, and we were losing nearly 300 hours each week to end-of-shift paperwork alone.

The paper chase didn't stop with our technicians, Kozlik continued. With over 120,000 work orders to process each year, our 7 person call center staff faced a constant 3-month backlog in closing out work orders. And, after all of that effort, we knew that we weren't tracking all of the work that was actually being performed in the field. Add to the equation countless radio calls between the technician and the call center, and it becomes clear that a manual system is a drain on the technician, the dispatcher, and the office staff.

Integrated solution
To address the need for data collection automation, Rush teamed with Barrington, IL-based Syclo Corp., a provider of mobile computing solutions. Syclo's mobile companion to the software, called S.M.A.R.T., allows technicians to use Windows CE-based handheld computers as their electronic clipboard, automating every aspect of data collection and dissemination. Using this technology, Rush planned to eliminate its paper-based work orders, thus reducing the load on the call center and increasing the productivity of the technicians.

In addition to going paperless Rush also needed to move information in real-time to and from its technicians. For this reason, Rush needed not just a handheld solution, but a wireless one.

For hardware, Novatel's Contact with a fully integrated wireless modem was selected. The computer includes a full keypad, a back-lit touch-screen, and weighs less than 22 ounces. In addition, it offers built-in power management software for longer battery life.

The final element of the solution was the wireless network. Rather than deploy its own wireless infrastructure, Rush teamed with Ameritech to use its Cellular Digital Packet Data (CDPD) network. CDPD is a wide-area wireless IP network that exists in over 3000 cities across the United States. Since CDPD is sold on a per kilobyte basis (as opposed to connect time), Rush found it to be the most economical solution, with a monthly cost of only $20 per technician.

Rush first deployed the solution among its 14-member response team, a unit that handles unscheduled corrective and emergency maintenance calls. The response team has immediate access to critical work order and equipment information. Because information flows wireless to and from the CMMS, the call center also sees the exact status of every assigned work order--dispatched, started, held, or complete. After the completion of each service call, the technician transmits work completion information over the CDPD network, immediately updating the CMMS, and then receives any new work assignments or changes. The technician proceeds to the next assignment, without ever having to return to the call center or fill out a piece of paper; at the end of the shift, the technician simply drops off his unit for use by the next shift.

With S.M.A.R.T., we have increased the productivity of our response team by nearly 30 percent, reducing technicians assigned to the team from 14 to 10, Kozlik said. We also eliminated our paperwork backlog completely and reduced our call center staff from 7 to 3 dispatchers. We were able to reassign employees to other tasks, including PMs, administrative support, and new customer service projects. Deploying the technology was the equivalent of gaining 10 staff.

With the increase in technician productivity and the decrease in clerical costs, Rush estimates that the system paid for itself in only 4 months.

Our new system has offered a number of improvements that enhance our patient care, Kozlik said. A very simple, but significant, example is the 95-percent reduction in our two-way radio calls. Those loud, blaring calls from dispatch to technician were very disruptive to patients, particularly those in critical care wards. Now, we need to use the two-way radio only in true emergencies.

Perhaps the most important benefit, in terms of quality of patient care, is our improved ability to perform proactive maintenance, Kozlik concluded. Now, if a technician spots a potential problem in the field, he or she can quickly enter it into the palmtop, and it is immediately available for approval and scheduling.

Our ultimate goal has been to gain better control of our maintenance processes by becoming proactive, not reactive. It all adds up to better service, longer equipment life-span, and better quality of care for our patients, he added. MT

Information supplied by Syclo Corp., 101 Lions Dr., Suite 118, Barrington, IL 60010; telephone (847) 842-0320; email info@syclo.com; Internet www.syclo.com and Novatel Wireless, Inc., 6540 Lusk Blvd., Suite C-170, San Diego, CA 92121 telephone (888) 888-9231; Internet www.novatelwireless.com