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328

9:59 pm
July 1, 2009
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A New Performance Measure: Timed Production Effectiveness

 

In the new world of multifunction manufacturing teams, limited resources, and relentless pressure on costs, managers are wrestling with three common issues: How to prioritize the use of limited resources. How to manage for optimum results. How to measure progress. If what you measure is what you get, perhaps we had better begin from this perspective. Unfortunately, there are several weaknesses to many of the popular measures.

Maintenance cost as a percentage of replacement asset value, a common metric for benchmarking, establishes cost objectives with no regard for operating intensity or age of assets.

What value is created by performance defined by a high percentage of scheduled to total maintenance if the scheduled tasks are unnecessary or improperly performed?

How valuable is reliability as a performance measure when required availability is significantly less than 100 percent or when there are substantial system redundancies?

Overall equipment effectiveness (OEE) and asset utilization measure availability and production output, but fail to include the cost of attaining increased availability and production.

To rectify these shortcomings, I would like to propose another measure of performance: timed production effectiveness (TPE). TPE can be applied as a measure of effectiveness of individual components as well as an entire facility.

TPE = timed availability x production output x conversion effectiveness.

  • Timed availability is the time a facility, system, or component is capable of producing a required result divided by the time windows in which production is scheduled or required. Timed availability adds two conditions to the conventional definition of availability:
  1. The target or objective is the actual time in which operation is required.

  2. In the event of a failure that slows or interrupts production, the interruption does not end for the purposes of calculating timed availability until production is fully restored.

  • Production output is production delivered in specification divided by the production objective. The concept of a production time increment also is applied so that the term reflects output when required to meet scheduled demand. Because actual output can be greater than scheduled output, production output may be greater than 1. If off-specification production is sold at a lesser price, a constant is applied to account for diminished income.
  • Conversion effectiveness is a conversion cost objective divided by actual conversion cost. The calculation must include all applicable conversion costs, including those for utilities (electricity, steam, water, etc.), operations, maintenance, administration, and waste disposal.
  • Production output is production delivered in specification divided by the production objective. The concept of a production time increment also is applied so that the term reflects output when required to meet scheduled demand. Because actual output can be greater than scheduled output, production output may be greater than 1. If off-specification production is sold at a lesser price, a constant is applied to account for diminished income.
  • Conversion effectiveness is a conversion cost objective divided by actual conversion cost. The calculation must include all applicable conversion costs, including those for utilities (electricity, steam, water, etc.), operations, maintenance, administration, and waste disposal.

Several people who have been introduced to TPE have commented that their enterprise prefers real numbers rather than normalized values. This requirement is easily accommodated. The denominator of conversion effectiveness divided by the numerator of production output results in conversion cost per unit output, a valuable performance measure in its own right. There are other vital measures that can be derived from TPE provided the information structure is properly designed.

During several discussions of TPE, the difficulty of obtaining accurate cost information has been cited as a major barrier. There are two answers:

  • First, it is imperative to know exactly how much it costs to deliver a given product. Lacking this knowledge it is easy to sell a product at less than the manufacturing cost, especially in today’s highly competitive climate where fractions may be the difference between profit and loss.
  • Next, regardless of whether accurate cost information is available today, competitive survival mandates it tomorrow. Those who cross the information bridge separating “guesstimated” and actual costs will have an enormous competitive advantage as well as crucial information with which to prioritize activities.

Whatever the measurement criteria and benchmarks for asset management, they must connect directly to unit objectives and profit, be familiar and understood by senior executives, and lead to optimized management decisions. Nothing else will attract the attention of those who control the funds. MT

  • To preserve the functions of our physical assets throughout their technologically useful lives
  • To the satisfaction of their owners, of their users, and of society as a whole
  • By selecting and applying the most cost-effective techniques
  • For managing failures and their consequences
  • With the active support of all the people involved.

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205

3:30 am
July 2, 1997
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Control Procedures with Configuration Management

Using maintenance procedures helps attain consistent results and establishes standards. Configuration management principles for controlling procedures help an organization become a world-class team.

A reliability-centered maintenance program is in place, condition monitoring is a fact, and total productive maintenance (TPM) teams are functioning well. Plant reliability is up, production is at peak levels, and corrective maintenance has been successfully minimized. Is it time to sit back and say all maintenance problems have been eliminated?

What about the people, including Occupational Safety and Health Administration (OSHA) and Environmental Protection Agency (EPA) representatives, who visit the plant and ask questions? How does ISO 9000 affect a maintenance program? The maintenance department is successful so far because it is staffed with good, experienced people. However, they do not seem to stay with the company as long as they used to. Those people and that experience may be harder to keep around in the future. So now what?

The impact of ISO 9000, OSHA, and the EPA is felt throughout industry. Procedures that should be performed must be documented so that the required reporting of what actually is done demonstrates that the desired result can be obtained. Procedures, whether written, oral, or traditional, usually spell out what tasks should be done. A task that is actually performed is recorded in quality control records, internal audits, process monitoring data, operator logs, and maintenance and repair records. The process of controlling documentation of what procedures should be and what is done is configuration management.

Why Use Procedures

  • Achieve standardized, consistent, correct performance every time
  • Instruct apprentices and new personnel
  • Control conditions during maintenance
  • Return equipment and systems to a known status upon the completion of maintenance
  • Provide a baseline for improvements
  • Capture experience and pass it along
  • Preserve lessons learned and best methods as part of a continuous improvement process

Procedures
The best industrial activities in this country have a good basis of maintenance procedures. Procedures help attain consistent results and establish standards. As industry relies more on cross-training and teams to accomplish routine preventive maintenance, standardization and consistency become more important. How procedures are used should vary with the intent. Safety, routine operations and maintenance, and special procedures for critical or complex repairs may be handled in different ways.

Sometimes resistance arises with’ the mention of procedures, leading to the technician’s question, Don’t they think I know what I’m doing? Asking these same technicians to document procedures recognizes their knowledge of the subject and enlists their support at the same time. It also makes them realize that not everyone performs in exactly the same way, which leads to which way is best and why. A standard procedure, openly developed with differing opinions considered, builds grass roots support. Procedures created through this method capture detailed personal knowledge not only of how to do the task well, but also of the problems and missteps that occurred in the past.

Proper procedures become reference material to settle a difference of opinion between veteran workers or to guide a new employee in the proper way to accomplish an assigned task. If procedures are used in an intelligent and consistent manner, they become everyone’s ally (see section, Why Use Procedures?). To maintain credibility, the procedures must be right; when they are found to be in error, they must be promptly and formally corrected.

Training
Procedures are related to the level of training in a maintenance organization. The fundamental, but unwritten, part of procedures is the basic knowledge required to execute a procedure. The higher the level of knowledge of the craft the worker has, the less detail is required within the procedure. The skill of the craft is the starting point from which procedures grow. However, requisite skills should be defined and not left to chance; the minimum skill level required should be stated. A training program must provide this skill to the newcomer. Experienced newcomers should be able to demonstrate the minimum level of knowledge and skills through testing, through professional certification, or by interview, as appropriate.

There may be logical levels of skill above the minimum that are appropriate for a specific organization. Advanced skill levels become important as cross-training and team building progress. On-the-plant-floor operations and maintenance overlap and operators can handle routine maintenance tasks, but there is a point where they rely on others for maintenance support and special skills. Many companies provide advanced training that qualifies individuals for special tasks and responsibilities. This training and certification-based testing or a practical demonstration qualifies an individual in the appropriate skill. Frequently, formal qualification for advanced levels goes hand in hand with additional incentives and rewards.

Configuration management
Controlling and changing procedures leads to configuration management. The goal is to maintain proper control, but it does not allow the administrative burden to become excessive. Configuration management identifies existing plant design characteristics and controls changes to ensure that structures, systems, equipment, and components meet design requirements; it ensures that the plant’s physical and functional characteristics are reflected accurately in selected plant documents (for example, design, procurement, operating, testing, maintenance, and training).

Configuration management becomes increasingly important as maintenance workers become more involved with integrating predictive maintenance and as the line of demarcation between maintenance and production becomes less distinct. A configuration management program

  • Provides a structure for managing change to prevent discontinuities, loopholes, omissions, and oversights
  • Provides a record of what has or has not been done with regard to the plant and its process, capacity, and equipment
  • Ensures that a technical review is accomplished before changes are made in order to remain in compliance with outside requirements and internal needs
  • Disseminates information regarding changes and requires that support be updated. Support includes drawings, repair parts and consumable stores, training (both operational and maintenance), operating and maintenance procedures, test procedures, and repair procedures.

Configuration management is widely used in the nuclear power industry. It is driven by regulatory agency concerns; public safety depends on each nuclear power plant’s ability to maintain the design safety margins throughout the life of the plant. The purpose of the program is to ensure that all changes made to plant systems, operating procedures, and maintenance will not inadvertently reduce the safety margin provided by the initial design.

Although most industries do not operate in an environment as public safety conscious as the nuclear industry, the amount of outside agency regulation and oversight is increasing. The organization that can look ahead and prepare to answer the hard regulatory questions will be ahead of its competitors. At this time, the rigorous program required by the Nuclear Regulatory Commission would not be cost effective for most other industries. However, many configuration management principles can be useful to any well-run business subject to outside regulation, oversight, or audit. The challenge is to adopt the principles and put them into operation cost effectively.

How is configuration managed? First, there must be an understanding of the design basis for the plant, its process, and equipment. Simply put, what is the plant designed to do and how is it supposed to be done based on the original plant design? The design basis must be defined because it is ground zero, the point of departure for all subsequent plant, process, and equipment changes. In the time the plant has been operating, many things may have affected the design basis.

Improper maintenance or operation may hinder the plant from doing what it was intended to do because of inappropriate repair parts or because operating procedures unknowingly reduce the capability of the plant. It may not be possible to completely reconstruct the design basis; in such cases, it is best to accurately determine the present configuration and capability and make this baseline the design basis.

Over the years, the design basis may have been deliberately changed; for example, the plant may now do something new, different, or better than it did originally. Modifications have been appropriate, but the modifications change the baseline. The design basis should have been changed to reflect the modifications.

Documents that state the design characteristics of the plant (or process or equipment) or that help maintain the design basis (procedures, test, drawings, parts lists, etc.) are an integral part of configuration management. These documents should be identified and handled in a special manner. They should be subject to special review when changes or modifications are proposed. The identification and control of design basis documents are keys to the long-term management of change. These documents must describe the plant as it actually exists. Changes should be subject to a technical review and trigger updating to support any changes.

Configuration management is implemented by

  • Identifying documents that define the design basis for the plant, its processes, and equipment
  • Establishing procedures for making changes in the design basis documents, including a technical review to determine whether the desired changes are technically sound and whether they will produce the desired effect
  • Assigning responsibility for implementing the change
  • Establishing procedures for updating the design basis documents, parts support, training requirements, maintenance and operating procedures, and dissemination of information regarding the change to everyone concerned
  • Monitoring the change or modification to ensure that it does what it was intended to do and that the support is updated.

The benefits to an organization with an orderly method of planning, executing, and tracking changes and modifications are significant. Major maintenance jobs can be accomplished promptly and correctly the first time because planning is based on good information, lessons learned from previous work of a similar nature have been incorporated, an accurate procedure is available, and the proper parts and drawings are ready. Changes and modifications accomplish what they are intended to accomplish because a technical review established a design that is based on valid, as-is conditions. The process continues after the change because procedures, drawings, parts, and training are updated to reflect the change. Benefits include the following:

  • Routine maintenance becomes seemingly self-executing
  • Regulators are satisfied
  • Production increases
  • Quality improves
  • Reliability moves up a notch
  • Worker pride and knowledge are increased
  • Lost and wasted motion is minimized
  • Costs are cut and the bottom line improves.

Program success
The successful implementation of all these topics will not be easy. What can be done to ensure the configuration management program will succeed?

First, institutionalize the process. Avoid the flavor of the month approach. Persistently and doggedly insist that the process be used. Do not settle for lip service. Starting any program is difficult, particularly if years of neglect must be overcome. Quietly educate so everyone understands what the program is expected to accomplish and what the benefits will be.

Second, devote the resources necessary to do the program right. However, do not let the program become a bandwagon for hangers-on. Keep the program as uniform and as simple as possible. Get the program running well in several small areas before expanding. Aim for the long haul; measure successes individually.

Third, learn from experience and follow up. Keep the program on track. Conduct internal audits and reviews to determine how the program is progressing and what the difficulties are. MT


Keith Young, a member of the Society for Maintenance and Reliability Professionals, is a senior associate for Maintenance Quality Systems, LLC, 1127-F Benfield Blvd., Millersville, MD 21108-2540; (410) 729-1290.

Self Examination Quiz

If an organization can answer “No” to all of these questions, it probably has a world-class maintenance organization.

  1. Have you found a repair part drawn from stores that is not the right part because the equipment needing repair has been modified?
  2. Have you found that stores does not have repair parts to support equipment because stores does not know the equipment has been modified?
  3. Do you find that various maintenance teams (or operations and maintenance teams) accomplish the same task with varying degrees of success?
  4. Are you unsure of the design production capacity of a piece of equipment? Are you unable to trace modifications that have changed that capacity and by how much?
  5. Have you ever attempted to use a drawing only to find that it was hopelessly out of date with respect to changes made in the equipment?
  6. Are you uncertain about the level of craft skill and knowledge held by the junior electrician or mechanic in your organization?
  7. As you approach the next repair job on a major piece of equipment, do you wonder whether tasks that were performed incorrectly and cost time and money last time have been corrected?
  8. Are you unable to demonstrate to an ISO 9000 auditor that you have done what ISO 9000 procedures require over the past 6 months?
  9. If the corporate legal department, in support of ongoing litigation, asked you to document the maintenance a particular piece of equipment had received throughout its lifetime, would you be unable to do it? If only the past 6 months was of concern, would you still be unable to document the equipment’s maintenance?
  10. Have you ever had a repair job fail upon post-repair testing because of improper reassembly, overlooked foreign objects left inside, or workmanship?

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226

1:18 am
July 2, 1997
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Chemical Plant Saves $220,000 with Predictive Maintenance Program

july97_Accelerometers

july97_Accelerometers

In May 1996, Mobil Chemical’s plant in Belleville, ON, launched a new predictive maintenance (PDM) program on its oriented polypropylene film manufacturing lines. This division of Mobil Oil is a principal supplier of film used for cookie and snack food wrappers at companies such as Hostess and Frito Lay. The new program was designed to predict, and thus prevent, machine failures that result in significant downtime and lost revenues.

Mobil’s Equipment Improvement Program (E.I.P.) team recognized the importance of monitoring the company’s rotating equipment. The data collected could provide invaluable information about machine performance. After thorough evaluations, accelerometers and switchboxes were purchased from Vibra-Metrics, Inc., Hamden, CT.

The monitoring system accelerometers were permanently installed and wired to remote switchboxes to provide more consistent data than possible with portable data collectors. The switchboxes were mounted in easily accessible locations away from risk of personal injury (caused by proximity of rotating machinery), but not in locations so remote from the machinery that visual or auditory checks were impractical. Local installation of switchboxes also allowed technicians to see that the line was running normally, thus eliminating faulty readings that may have occurred if the readings were taken remotely.

The first installation of accelerometers and switchboxes was completed during a capital upgrade on one of the oriented polypropylene lines. Sensors and switchboxes were delivered and installed, and began providing data approximately 6 weeks from the time the order was placed.

From what Mobil’s maintenance personnel learned during this initial installation, and with some preliminary planning, they were able to shorten the installation time for the next line to approximately 4 days. As of January 30, 1997, approximately 550 accelerometers had been installed on the two lines.

A predictive maintenance program schedules periodic readings for all mounted bearing accelerometers on a monthly or biweekly basis and for accelerometer locations cited on a troubleshooting list. Through April 1997 the staff recorded 27 “saves” that prevented unscheduled machine outages and equipment repair that could have cost the company more than $220,000. In all, 75 formal work order requests were issued by technicians to make repairs from diagnostics that could have resulted in eventual failures.

Savings are based on 1.5 times actual labor costs, actual parts costs, and a $2000/hour line cost. Cost avoidance reporting showed management that the program has paid for itself within the first year of operation. MT


Information supplied by Vibra-Metrics, Inc., Hamden CT; (800) 873-6748; e-mail sensortalk@aol.com Continue Reading →

218

11:55 pm
July 1, 1997
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The Guru Principle

bob_baldwinToday, few people question the potential rewards of predictive or condition-based maintenance. But why does this modern approach to maintenance deliver spectacular results in one plant yet fall short in a similar plant? According to Ralph Buscarello, the primary reason most programs fail to reach theirpotential is the find-and-replace mentality of many maintenance organizations. They create some savings by finding pending failures in a timely manner and by replacing the components before they fail in service. However, much bigger savings accrue in plants that are focused on improving and managing machinery. These organizations use vibration, balancing, and alignment technologies to identify and rectify the root cause of the failure and correct it rather than simply swap out the failed component.

Buscarello is the founder of Update International, a vibration and alignment training and consulting company based in Denver, CO. I had the opportunity to hear him explain the precision maintenance approach to machinery management and improvement recently, while attending a special presentation of his seminar on “Vibration Understanding from the Supervisor and Manager’s Perspective.” The course was arranged by the Society for Maintenance and Reliability Professionals as a part of the society’s free workshop program for members.

Buscarello presented a number of observations on the makeup of truly successful programs. One of the suggestions that made a lot of sense to me was the Guru Principle, whereby an appropriate person is designated the plant guru for a maintenance technology and is given license to acquire knowledge and develop plant capabilities for that subject.

For example, the alignment guru would strive to learn everything about alignment, both good and bad, from plant personnel and industry experts. Although the alignment guru becomes the plant precision alignment expert, he is not expected to do the alignment himself. Instead, he is responsible for improving alignment practice in the plant. The person selected as guru must relate well to people because he is expected to be an agent for changing attitudes and work practices. He serves as consultant and coach and works with management to set company standards for precision, evaluate performance, review training needs, and scout for new talent.

The guru is judged not on how well he can align shafts personally, but on how well others do alignment. Which brings up the question: How are you being judged? MT

Thanks for stopping by,

rcb

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630

9:09 pm
July 1, 1997
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Client/Server Software: What Is It All About?

Modern program architecture benefits provide flexibility, reliability, and responsiveness for larger applications.

Client/server methodology and architecture offer a versatile approach to the development and deployment of software for major computer applications critical to strategic planning and enterprise operations. Maintenance information systems and computerized maintenance management systems (CMMS) for larger plants fall into this critical software category.

The client/server approach benefits both the software developer and the user. It is especially important for larger applications if the system is to provide the reliability and responsiveness associated with classic mainframe systems.

As defined by Microsoft Corp., client/server architecture generally applies to a software architecture in which functions are split into independent tiers or collections of “services” and “requesters” on a single computer or several computers. But the potential of client/server technology is broader. It encompasses more than a personal computer accessing a server on a network. Its greatest potential is in creating and managing distributed tasks, business logic, and shared, reusable software components so the end product is efficient, reliable, and less costly.

The key to maximizing this strategy is the application of a three-tiered architectural approach to client/server solutions that is generally considered to be the leading model for application development. This approach separates the various components of a client/server system into three logical tiers of services that come together to create an application:

  1. User services, which provides for presentation of information, functionality, and navigation
  2. Business services, which provides for shared business policies and rules, and generation of business information from accumulated data
  3. Data services, which provides for definition of data, and storage and retrieval of persistent data.

User services
The user services tier is responsible for supporting users as they interact with the application. It presents information to and gathers data from the users. This tier’s key characteristics include

  • Giving users control as opposed to the software package taking control
  • Supporting the activities users perform while using the package
  • Providing the visual interface for presenting information and gathering data
  • Linking together a collection of business services that deliver business capabilities.

Working functions of this tier include

  • Relate with other user services and the business services tier
  • Use business services to obtain information and make requests
  • Format content, present it to the user, and interpret users’ actions.

The user services tier presents information to users and generates a form that is most appropriate to the current user. User services is a secondary data source for the business services. Most of the business data received will come from the data services. Users are not aware of the data services consumed by the business services tier.

Business services
The business services tier links related tasks with the relevant business rules. Business tasks are defined as the steps needed to accomplish a business decision. The key characteristics of the business services tier include

  • Linking related business tasks with the relevant business rules
  • Responding to requests from the user services to execute a related business task
  • Converting data received from business and user services into information
  • Securing the data services needed to accomplish the business task with the relevant business rules.

Working functions of this tier include

  • Support the user services by defining available business tasks, information needed by the business task, and information that is returned by the task
  • Process information sent by a user-initiated action
  • Interact with the data services by defining the rules needed to manipulate, structure, and use the data.

The business services tier is the only service in an application that has a relationship with both the user and data services tiers. The relationship of business services with data services is quite a bit different. Business services defines the rules or some of the rules needed to manipulate data. The business services tier enforces the rules the package uses to manipulate data.

Data services

The data services tier is responsible for maintaining the availability and integrity of data as a corporate asset. This tier supports the lowest level used in manipulating data within an application.

Key characteristics of the data services tier include

  • Defining, maintaining, accessing, and updating all data in the database
  • Managing and satisfying business services requests.

Working functions of this tier include

  • Has no relationship with user services
  • Uses the business services to provide information and determine if data are valid.

Data services is primarily responsible for accessing the raw data for the business services tier. Business services then takes the data and applies the business rules to generate the information a user has requested. User services takes the information and delivers it in a form that is meaningful to the user.

Assembling a solution
Once properly designed, components are then assembled and applied to the appropriate logical tier. Many factors should be considered in making component distribution decisions, including

  • Locality of reference–putting a component where it is best used, minimizing overall network traffic in the physical environment
  • Data distribution–taking network load into account
  • User interfaces–providing standard user interaction
  • Correctness–serving competing applications on the network, including such issues as the possibility of deadlock, fair allocation of resources, and security
  • Reliability–avoiding excessive demands on the network that may make it unstable
  • Network reliability–serving competing applications.

Once the software components are applied to the appropriate logical tier, it is easier to distribute them in the physical environment. Ideally, physical location decisions are driven by business and operational needs. In reality, there are technological limits, many of which come from the software package itself.

For example, if a CMMS is designed around a “fat client” or two-tier architecture, performance is limited and the CMMS cannot support large numbers of concurrent users. A fat-client architecture places most services on the desktop personal computer and the data on a server. Smaller organizations with a few users will not find this method to be a problem, but larger, multiplant, multidepartmental organizations accustomed to mainframe-level performance will be frustrated by increased response times, slow performance, and increased network traffic.

Distributed CMMS applications must take network usage into account. An application that places excessive demand on the network may be unstable. Thus, these applications must be designed to use the network realistically.

For multiuser systems, the total concurrent user population is only one factor in the measurement of response time. Components should be deployed to minimize the number of network “calls” and the amount of data transferred across the network. A developer can do this by locating components as close as possible to the resources they will consume most heavily. For example, user services (tier one) should generally be located on the client workstation. Business services that interact heavily with other components should be physically located on an application server (tier two). Business components that access data stores heavily are best located on a database server (tier three).

Client/server benefits
Microsoft’s software development experience as well as the experience of Bonner & Moore has shown that a tiered, component-based solution approach to client/server development has many advantages over traditional application architectures.

From a development team organizational standpoint, the component-based approach splits teams into two groups: one group develops core components (custom controls, stored procedures, object linking and embedding–OLE–servers, and so on) that can be useful to many applications. The second group builds business solutions by integrating the services provided by these components. This approach has many advantages over traditional application development.

  • Developers can specialize in what they are best suited for, which lowers training costs. For example, database-oriented programmers write stored procedures while visual programmers design user interfaces. This method translates into lower software licensing costs to the user.
  • Reusable components can be written in a variety of programming languages such as Visual BASIC, Microsoft Visual C++, or SQL, providing a great deal of language independence and the opportunity to develop in the language that best suits the specific task. This advantage translates into more efficient soft-ware code and a more responsive system.
  • Components can be deployed on the network to maximize efficiency, performance, security, and ease of maintenance. Users get better response times and better use of current computer technology. The package also can grow with the user community.

These and other advantages make the three-tiered component solution approach a sound method of application development for mission critical systems. It also provides reliable, mainframe-level performance in a distributed client/server environment. MT


Emily P. McAnally is manager, software development and support, Bonner & Moore Associates, Inc., 2727 Allen Pkwy., Houston, TX 77019; (713) 522-6800.

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