Predictive maintenance operating cost

A survey of 500 plants that have implemented predictive maintenance methods indicates substantial improvements in reliability, availability and operating costs. The successful programs included in the survey include a cross-section of industries and provide an overview of the types of improvements that can be expected. Based on the survey results, major improvements can be achieved in maintenance costs, unscheduled machine failures, repair downtime, spare parts inventory, and both direct and in-direct overtime premiums. In addition, the survey indicated a dramatic improvement in machine life, production, operator safety, product quality and overall profitability. 

A side benefit of predictive maintenance is the automatic ability to monitor the mean-time-between-failures, MTBF. This data provides the means to determine the most cost-effective time to replace machinery rather than continue to absorb high maintenance costs. The MTBF of plant equipment is reduced each time a major repair or rebuild occurs. Predictive maintenance will automatically display the reduction of MTBF over the life of the machine. When the MTBF reaches the point that continued operation and maintenance costs exceed replacement cost, the machine should be replaced. 

The overall benefits of predictive maintenance management have proven to substantially improve the overall operation of both manufacturing and process plants. In all surveyed cases, the benefits derived from using condition-based management have offset the capital equipment cost required to implement the program within the first three months. Use of microprocessor-based predictive maintenance techniques has further reduced the annual operating... 

Expertise required to operate One of the objectives for using microprocessor-based predictive maintenance systems is to reduce the expertise required to acquire error-free, useful vibration and process data from a large population of machinery and systems within a plant. The system should not require user input to establish maximum amplitude, measurement bandwidths, filter settings, or allow free-form data input. All of these functions force the user to be a trained analyst and will increase both the cost and time required to routinely acquire data from plant equipment. Many of the microprocessors on the market provide easy, menu-driven measurement routes that lead the user through the process of acquiring accurate data. The ideal system should require a single key input to automatically acquire, analyze, alarm and store all pertinent data from plant equipment. This type of system would enable an unskilled user to quickly and accurately acquire all of the data required for predictive maintenance. 

The purpose of predictive maintenance is to minimize unscheduled equipment failures, maintenance costs and lost production. It is also intended to improve the production efficiency and product quality in the plant. This is accomplished by regular monitoring of the mechanical condition, machine and process efficiencies and other parameters that define the operating condition of the plant. Using the data acquired from critical plant equipment, incipient problems are identified and corrective actions taken to improve the reliability, availability and productivity of the plant. 

Table 1.4 lists the priority R D needs that were identified for burners, boilers, and furnaces. Essentially all of these needs require some amount of testing. These needs were generated from the following end-use requirements increased system efficiency reduced NOx, CO, CO2, and particulate emissions increased fuel flexibility more robust and flexible process control and operations better safety, reliability, and maintenance lower capital and operational costs faster, low-cost technology development and enhanced system integration. Coupled with these needs are some barriers to improvement financial risk, inability to accurately predict the performance of new systems, lack of industry standards, and the wide gap that often exists between the research done at a small scale that needs to be applied to industrial-scale systems. Testing is often required to address some of these barriers. 

Effective preventive/predictive maintenance programs will be used to anticipate and predict maintenance problems in order to eliminate the uncertainty of expected breakdowns and high repair costs. Predictive maintenance wiU not be limited solely to the detection of failure but will proactively identify and eliminate the root causes of chronic problems. Preventive/ predictive maintenance programs will be adequately staffed to cover adl major assets within the operation. Maintenance wiU maintain current techniceil knowledge and experience for applying a combination of predictive technologies that is best suited for the specific application or system. 

Preventive/predictive maintenance Continuous reliability improvement Reliability-centered maintenance Maintenance parts/materials control Maintenance storeroom operations Work order and work control Maintenance planning/scheduling Maintenance budget and cost control... 

Building Automation and Control Systems Operation and Maintenance PRODUCT PREVENTIVE/PREDICTIVE MAINTENANCE PROCEDURES TROUBLESHOOTING AND REPAIR TIPS CRITERIA FOR REPAIR VERSUS REPLACEMENT HOW MUCH SHOULD MAINTENANCE ON MY CONTROLS COST SUMMARY... 

To meet the above challenges, two ftmdamental initiatives are under way, namely, shifts to reliability-centered maintenance and predictive maintenance. Broadly speaking, prior to the maintenance revolution, the utilities maintenance approach had essentially been one of preventive maintenance on all components after fixed time intervals, irrespective of the components criticality and actual condition. The shortcomings of this approach included the following (1) overly conservative maintenance requirements, (2) limited gains in reliability from investments in maintenance, (3) inadequate preventive maintenance on key components, and (4) added risk of worker exposure to radiation through unnecessary maintenance. Anticipated benefits of the revised approach are related not only to reduced maintenance costs but also to improved overall operational reliability. 

Goals and Objectives of FEL The FEL work process must enable nearly constant consideration of changes as the work progresses. FEL phases must consider the long-term implications of every aspect of the design. Predictability of equipment and process system life cycle costs must always be balanced with operations and maintenance preferences, as well as the need for the project to maintain its profitability or ROI (return on investment). Additional important goals and objectives of FEL projects are as follows ... 

In many cases, the approach used has been mechanistically or empirically qualitative, with the primary purpose of developing immediate solutions to pressing environmental problems, or of improving plant maintenance and operating schedules and procedures. However, the need to preempt costly outages, extend plant lifetimes, or perform environmental assessments is leading to efforts to develop predictive models. The primary emphasis in this chapter is the development of such models and how electrochemical methods can be used in the process. 

The capital cost of a reactor is a function of the number of stages, their complexity and operating conditions, and of the flow rate and properties of the reactant stream. This cost has to be financed and repaid over a certain period of years from the profit of the plant. Experience gives some idea of the kind of maintenance that is needed with various kinds of reactors and what fraction of the year they are liable to be out of production. All these factors must be considered, together with the estimated useful life of the plant and current economic predictions, in order to arrive at a number C, the combined cost per unit time of these charges. 

Total operation, maintenance, and amortization costs at the estimated actual load factor for the first year of the Buckeye plant s operation (48% of theoretical full-load capability) will be 50.9 cents per 1000 gallons. Operation at 98% of theoretical full-load factor (the plant s maximum practical capability) would result in total costs of 33 cents per 1000 gallons (Table II). The 33 cent figure can be compared with previous cost estimates made by this company (I, 2, 5), the Office of Saline Water (8), or others (9), who have usually assumed full-load or virtually full-load operation in such calculations. Most of the factors making up this cost estimate have been guaranteed to the town of Buckeye. However, the 48% load faotor is an estimate based on the historical demand pattern for untreated water around the year. It is difficult without actual experience over the next year or two to predict the effect, if any, of a substantial rate rise on the usage of water and the load factor. 

With the corrective actions taken to date, it has been possible to increase by 1.1% the global zinc extraction. The global zinc recovery has increased by 2.3% and it is predicted that with the better control of the circuit and with an optimal residue wash, the proposed goal of 94.5% zinc recovery will be easily obtained during this year. The success of the improvement project will more than justify its cost of 6.6 million U.S. dollars, with an annual production increase of 2,500 tonnes of refined zinc. As well, a decrease in maintenance cost is expected along with an increase in the availability of the equipment because of the substitution of filtration equipment and the operation of the gypsum removal step. 

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