Machinery Component Maintenance and Repair P2 pot

Maintenance work order planning and scheduling continues to be a largely manual set of procedures throughout the hydrocarbon processing industry. There are, however, several systems which support daily work planning and scheduling. One such system is a skills inventory file that provides daily information on available personnel for use in manual plan- ning and scheduling of maintenance work. Another is the computer-based file containing standard maintenance procedures that can be retrieved for preparation of work orders and in estimating manpower time requirements. Additionally, other maintenance-related systems, such as preventive- maintenance systems and inspection-support systems, may generate work orders for inclusion in daily maintenance schedules. Work order planning and scheduling also is supported by materials and parts inventory systems. The actual computer-based scheduling of daily maintenance manpower resources, however, has remained an elusive goal. Recent systems work has aimed at scheduling shop work where forecasting work requirements is easier than forecasting field work. Incentives for Computer Systems The primary incentive for design and implementation of maintenance- related support systems is the potential for reducing maintenance-related costs. The cost of keeping hydrocarbon processing plants running includes maintenance expenditures. These typically range from 1.8 to 2.5 percent of the estimated plant replacement value. Justification of Systems Although process industry companies generally agree that maintenance- support systems* are a viable means of reducing maintenance costs, there is no general agreement on the size of benefits available or the source of these benefits. For this reason, there are probably as many ways to justify computer installation as there are computer applications: 1. Reduced clerical effort. 2. Improved utilization of maintenance work force. 3. Improved equipment reliability. 4. Reduced inventory costs. 20 Machinery Component Maintenance and Repair * Also called “CMMS,” for computerized maintenance management system. Reduction of clerical effort is used when filing, recording, and retriev- ing become excessive. Sometimes a reduction in clerical staff may even be possible after a computer system is installed. However, the relief of key personnel from clerical responsibilities is usually more important as a justification point. For example, a major oil company partially justified installation of a fixed equipment inspection system at a large refinery on the basis that inspectors could be relieved of the clerical duties of filing and retrieving inspection information. This company also found record keeping on inspection, thickness measurement, and corrosion rates to be more consistent and far more accessible. As a result, information com- piled by this refinery’s inspection department is far more useful today than when such information was kept mostly in filing cabinets in the individ- ual inspector’s office. Improved utilization of maintenance manpower is widely used as a means for justifying turnaround scheduling systems, planning/scheduling systems, and inventory control systems. Results from a carefully con- ducted analysis of work delays created by existing manual procedures are compared against improvements expected from computerized systems. Man hours saved—multiplied by hourly rates for maintenance personnel—sometimes provide substantial justification for computer systems. Improved equipment reliability, with resulting reductions in equipment downtime and improvements in plant throughput, are obvious justifica- tions for preventive and predictive maintenance systems. Some companies have found that benefits from this source alone can provide a payout as quickly as one year from the initial computer system investment. In the complex process environment of the modern refinery or petrochemical plant, monitoring equipment performance, effective diagnostics, and early recognition of equipment problems require computer speed and support. Improved management reaction to plant equipment problems also has justified computer systems. This is a difficult area to quantify. However, if previous costly equipment failures can be identified as preventable through timely management information, this becomes a very real justifi- cation for system installation. Materials inventory and stock catalog systems have been justified by many companies based on reduced inventory. Computer systems have improved inventory management and control, reduced overall stock requirements, and improved warehouse response to maintenance require- ments for materials and spare parts. Identification of obsolete parts and materials is far easier and far more thorough when computer support is available. Although many quantitative methods exist for justifying computer- based systems in the maintenance area, many such systems are justified Maintenance Organization and Control for Multi-Plant Corporations 21 by what is called the “faith, hope, and charity” method. Maintenance management simply has faith that maintenance can be made more effec- tive and can be controlled better if maintenance activities and costs can be measured. Through computers, maintenance management also hopes effective record keeping will preserve effective procedures and the main- tenance department will be less vulnerable to loss of key personnel because these procedures are recorded within a computer system. The element of charity exists because the accounting or operations depart- ments may have computers which are not fully utilized and are, thus, avail- able for maintenance-related applications. Unfortunately, the “faith, hope, and charity” justification technique too often has resulted in installation of systems which were thrown together on a part-time basis by data processing personnel and imposed on the maintenance department in the total absence of any obvious maintenance coverage and/or desire for such systems. The result has been immediate rejection of the system by maintenance personnel and a setback in the maintenance department’s acceptance of computer support of any type. Setting Up an Effective System As previously mentioned, there are a variety of computer systems being installed in processing plants. These systems can be installed either as “stand-alone” systems or as systems which exchange data with other related systems. Just where the first system is installed depends mainly on where help is most needed—or where computerization would produce the most significant benefits. With any system, however, there are certain “places to start” which are absolutely vital to system success. The maintenance department which hopes to realize benefits from computer systems must start with a convinced, dedicated management and recognize that system acceptance in the maintenance department must be earned. The manager who has a system designed and installed as “something we can try to see how it works out” has wasted a lot of company money. If the maintenance manager is not solidly convinced the contemplated system is needed and if he is not dedicated to its success, then the system is likely doomed to failure or to only partial realization of potential benefits before the first computer program statement is written. Maintenance management has long recognized that certain manage- ment techniques must be used to implement any change. Unfortunately, these techniques are not always applied when the change involves a com- puter. Communication, participation, involvement, and training all must 22 Machinery Component Maintenance and Repair be used to ensure that need for the system is generally recognized through- out the maintenance department and that the system is accepted by maintenance personnel as a problem solver. One of the more effective techniques for implementing a computerized system is to build upon exist- ing, manual systems in order to permit minimal change in the informa- tion input activity even though major improvements are effected in available reports and analyses. A common misconception is that a computer application requires a large volume of additional routine data. If a good manual system exists for preventive maintenance scheduling, inventory control, or other func- tions, the computer system often requires no more routine input informa- tion. As reports are produced, the volume should be carefully limited to necessary information. Report formats should be developed with the ulti- mate user’s participation. Finally, results should be thoroughly communi- cated throughout the maintenance organization. A plant also should be careful to allocate the resources necessary to support the system’s implementation effort. Computer applications often require a one-time data entry—such as equipment specifications or mate- rial descriptions—which imposes a short-term load on available person- nel. These tasks may be assigned to existing personnel or contracted to outside firms. The temptation to use existing personnel on a part-time basis has often proven counter-productive to final system success. After programming, implementation, and training it is also essential that the system be supported. The new maintenance system’s “credibility” among maintenance personnel is extremely fragile during the first few months of its existence. Hardware problems, computer priorities and program “bugs” can be disastrous to system acceptance. Parallel opera- tion of existing manual procedures with the computer system for a period of time has been used to prove the computer system and to demonstrate the improvement in information availability and analysis. Finally, when implementing a computerized maintenance program, it is important to progress from one system to the next at a speed that will not create confusion or misunderstanding. If multi-system maintenance support is a plant’s goal, then a long-time strategy for system implemen- tation is necessary to ensure logical growth compatible with needs (and abilities) of plant personnel. To overcome the “too much, too soon” problem, one major chemical company has designed a modular system for eventual installation at all of its plant sites. The modules are made avail- able to the plants—but not forced upon them. Each plant is encouraged to formulate a long-term strategy for use of these systems and to use the techniques of communication and personnel involvement in implement- ing systems at its own pace. This modular, but preplanned concept of com- puter system installation at plant sites permits growth into a totally Maintenance Organization and Control for Multi-Plant Corporations 23 integrated system, even if years separate the installation of individual systems. Manuals Prepared To accomplish the preventive maintenance control system, in a large multi-plant environment, manuals are prepared by technical specialists listing the specific maintenance tasks for each equipment item at the operating plants. The manufacturer’s recommendations and a plant’s own experience are considered in determining the extent of coverage for maintenance procedures and frequency. Differentiation between running maintenance and shutdown maintenance is also made. As operating requirements change, these procedures are improved and updated and revised pages are issued to keep the manuals current. Needless to say, these “manuals” are kept and updated on computers. Paper printouts are produced, as needed. Maintenance tasks range in frequency from daily shifts to several years, depending on the equipment type, its loading, and serviceability. Mainte- nance tasks are monitored by the staff at the home office and passed through the data processing equipment that performs the following functions: 1. Prints schedules and feedback cards. 2. Digests feedback information on completed or rescheduled maintenance. 3. Prints reports showing tasks performed or deferred. 4. Calculates percent compliance. 5. Accumulates actions taken and total time expended. 6. Prints addenda to the schedule and addenda feedback cards for uncompleted tasks. The percent compliance to the schedule for each plant is separated into “normal” and “downtime” categories. This separation permits evaluation of the schedule portion controlled by the plant manager—that portion he can do only during an emergency or planned shutdown. Central manage- ment is thus automatically given the opportunity to pass judgement on the desirability of rescheduling “downtime” PM items. Compliance reports are issued monthly and sent to plant managers and the home office. At the beginning of each month, the computer prints work schedules for all maintenance tasks due in the particular month. These schedules cover machinery and equipment for each plant in the system. Copies are sent to each plant manager and to the home office staff. The schedules list all the PM tasks that must be done during the coming month. An advance 24 Machinery Component Maintenance and Repair schedule of downtime tasks, covering the next three months, is also included. This advance notice assists the plant manager in planning down- time task performance in case an emergency shutdown occurs. The com- puter schedules are accurate because maintenance task timing is based on the date they were last performed and the frequency assigned. Many inter- national design contractors offer maintenance services that integrate other aspects of asset management (Figure 2-1). Along with the schedules, the data processing equipment prints out a data log to feed back completion or rescheduling information. This mode of tracking is used by plant maintenance personnel to record actions taken, time expended, date completed, and any pertinent remarks concerning findings when the task was done. The log issued to the plants at the begin- ning of the month must be answered on the last day of the month. Performance Reports The preventive maintenance performance report shows the tasks which are performed on time, performed late, are rescheduled, or remain in a deferred state. It allows the plant manager and home office management to evaluate performance. The number of tasks scheduled, rescheduled, and completed is listed at the end of the report along with the compliance per- centages and the total time in hours for normal and downtime categories. Preventive maintenance performance reports are generated by any of the commercially available CMMS software programs. Preventive maintenance tasks that were not completed as scheduled are summarized in addenda to the schedule and sent to plant managers as reminders. The addenda are printed monthly by the computer, based on noncompliance of tasks previously scheduled. Deferred tasks continue to appear on these addenda until completed. A set of feedback requests accompanies the addenda for the reporting of work completed. Data reported via the feedback requests are accumulated by the com- puter. This includes time expended for each maintenance task and the number of times actions such as cleaning, filling, lubricating, overhaul- ing, or testing are performed. A report of accumulated maintenance statistics is produced by the computer and is used by the operations management to make an audit of work done. Breakdowns Reduced Since the incorporation of this system at large multi-plant corporations there has been a very definite trend of reductions in breakdowns. This allows nearly all maintenance work to be performed on a planned basis Maintenance Organization and Control for Multi-Plant Corporations 25 26 Machinery Component Maintenance and Repair Figure 2-1. Maintenance as part of Asset Management. (Source: SKE Publication 51605 2003) and on an optimized time schedule to provide the best possible on-stream factor. In the actual performance of planned maintenance work, there can be several approaches. One approach is to have complete in-house mainte- nance and supervisory ability at each plant with occasional subcontract- ing for large peaks. A second is to subcontract all maintenance work, thus eliminating the requirement for maintenance personnel at individual plants. Each system has obvious advantages and disadvantages depending on plant size, location relative to other area plants, etc. Recognizing good planning and skilled supervision as the key elements in low cost major maintenance, an intermediate approach has been taken at some plant locations. Some of the main considerations of this approach are: 1. The plant manager is fully responsible for normal maintenance. Each plant employs an absolute minimum number of resident maintenance people consistent with the day-to-day requirements, plus a normal backlog of work which can be accomplished while the plant is running. 2. The responsibility for planning major maintenance and turnarounds would come under the jurisdiction of a corporate maintenance manager working in close conjunction with the plant managers. His group of mobile planners, technicians and maintenance staff repre- sent a well-trained nucleus for supervising major maintenance work to supplement the normal plant maintenance group. These individ- uals travel from plant to plant as required. This makes it unneces- sary to have skilled supervision at each facility capable of handling planned major maintenance work. By scheduling the total corporate maintenance requirements, this same skilled group can handle a large work volume at a number of facilities at overall lower cost and inject a higher than normal experience factor into the supervision aspect of maintenance. The major maintenance work is performed using standard critical path scheduling, manpower and tooling plan- ning, cost control procedures, inspection reports, etc. 3. Supplementary maintenance manpower is provided by using care- fully selected local contractors. However, by having a well-trained nucleus of supervisory and maintenance personnel available from within the company, overall manpower efficiency is kept at a higher level than normal, thus resulting in lower costs and reduced outage time. Operators are used where possible during turnarounds which involve plant shutdown. 4. The travel and living costs for the flexible, rotating group of main- tenance technicians and planners is a minor cost factor compared to the more efficient use of personnel and reduced outage time. In many Maintenance Organization and Control for Multi-Plant Corporations 27 cases, the technician and central maintenance group are geographi- cally located near key facilities, since this is where they spend most of their time. Discussion of any maintenance concept is incomplete without includ- ing a method of spare parts control. The goal of an effective spare parts program is to keep the investment in capital spares to a minimum without seriously jeopardizing the plant onstream factor, and administering the spare parts program at the lowest possible cost. Only experience, after an extended operating period, will determine the adequacy of decisions made in this regard. The spare parts program at a multi-plant corporation should most cer- tainly be administered on a centralized basis. The commonality of equip- ment makes this a prerequisite for low total spare parts investment. The same central mechanical engineering organization responsible for moni- toring field mechanical problems is also responsible for the initial selec- tion of spare parts and the approval for reordering major spares. Initial spare selections are based on equipment manufacturer recommendations, operating experiences, and careful analysis of what is in existence. To obtain the best possible price, major spare parts are negotiated as part of the original machinery or equipment purchase. Central Parts Depot Specific items not common to other facilities and small, normal spares are maintained at individual facilities. Certain major components common to more than one operating facility and some parts showing high usage are stocked at a centrally located parts depot. This concept allows for a lower total investment in spares. Since spare parts handling, packaging, and long-term storage are so critical and require specialized knowledge, it is necessary to provide this capability at only one location. It is possi- ble to ship spare parts from this depot on a 24-hour, seven day a week basis. Transportation arrangements normally keep the total shipping time to less than eight hours. With most maintenance work performed on a planned basis, actual plant startup delays due to the central stocking depot concept are rare. By careful analysis on ordering of initial spares and the central depot concept, major corporations have been able to lower the investment in spares (expressed as a percentage of equipment investment) from approxi- mately 5 percent a few years back to under 3 percent on new plants. To keep the administration of replacement spare parts at a minimum cost, a central data processing system has been established. As parts are 28 Machinery Component Maintenance and Repair used, data are sent to the corporate office for computer input, which auto- matically generates the parts replacement purchase order. The authorized parts level is periodically and automatically reviewed to prevent reorder- ing of parts with a low turnover. A block diagram showing the spare parts support system is shown in Figure 2-2. A composite listing of all parts in the system is available at the corporate office to facilitate the identifica- tion of parts interchangeable with other facilities. Plant Engineering Plant engineering referred to here includes those process and mechani- cal services required for monitoring plant operations, the prompt resolu- tion of special plant problems, normal debottlenecking, and special engineering assistance as required in performing maintenance work. A Maintenance Organization and Control for Multi-Plant Corporations 29 Figure 2-2. Block diagram of operations spare parts support system. [...]... monitoring methods and processes, cheaper transportation and communication costs, are indicative of increasing advantages obtainable in the future from centralized concepts in plant maintenance and engineering for multi-plant corporations 32 Machinery Component Maintenance and Repair Figure 2-3 Simplified computer program used to evaluate compressor efficiencies Maintenance Organization and Control for... presented at the Seventh Turbomachinery Symposium, Texas A&M University, College Station, Texas (December 1978) Adapted by permission Updated in 2004 34 Machinery Component Maintenance and Repair Among other duties, the T/A coordinator screens and approves the planning and scheduling efforts of maintenance or contractor personnel involved in major machinery T/A’s after the senior machinery specialist has... those of a machinery advisor and quality control person who augments the mechanical supervisor and reports to the senior machinery specialist for work direction and guidance His responsibility and authority extends from machine inlet nozzle to machine outlet nozzle and includes lube and seal oil systems His work begins after all required blinds have been installed and ends after every item of machinery. .. Six Months Before T/A, the senior machinery specialist must: • Commence refresher training for mechanical supervisors, craftsmen, and designated contract personnel • Arrange for vendor assistance • Review the machinery T/A schedule 36 Machinery Component Maintenance and Repair Figure 2-4 Typical worklist page for major compressor turnaround Maintenance Organization and Control for Multi-Plant Corporations...30 Machinery Component Maintenance and Repair centralized organization of specialists within the operations department is charged with this responsibility for the network of facilities Major engineering design and construction work related to new plants and plant expansions is handled by a separate corporate engineering department and will not be discussed in this section... up-to-date listings of parts on hand to personnel requiring this information The plant senior machinery specialist is generally charged with responsibility and authority to direct planning and execution of the machinery portion of the T/A His background and experience should make him uniquely qualified for this job, and as senior resident expert he would be thoroughly familiar with all machinery affected by the... how much time and effort are required to successfully plan and execute an overhaul of a particular piece of equipment A proper turnaround involves preplanning and teamwork among plant technical, warehouse, purchasing, safety, operations and maintenance forces, as well as with the original equipment manufacturer and other noncompany sources In the case of sophisticated problems, consultants and laboratories... Organization and Control for Multi-Plant Corporations Figure 2-5 Typical spare parts tabulation 37 38 Machinery Component Maintenance and Repair Three Months Before T/A: • He meets with designated turbotrain T/A engineers for detailed briefing and solicitation of additional input Two Months Before T/A, the senior machinery specialist should: • Review final (detailed) T/A plan for each train • Verify that work... restore machinery to a reliable, smooth-running, and efficient operation Managing these resources and documenting the results presents a real challenge to those assigned the task of heading up the overhaul effort This segment of our text deals with turnaround management principles that must be understood and considered by maintenance personnel on the plant level Assignment of Qualified Personnel* Major machinery. .. troubleshooting, and repair He normally performs work which involves conventional engineering practices but may include a variety of complex features such as resolution of conflicting design requirements, unsuitability of conventional materials, and difficult coordination requirements His normal sphere of activity requires a broad knowledge of precedents in turbomachinery design and a good knowledge of principles and . nearly all maintenance work to be performed on a planned basis Maintenance Organization and Control for Multi-Plant Corporations 25 26 Machinery Component Maintenance and Repair Figure 2-1. Maintenance. involvement, and training all must 22 Machinery Component Maintenance and Repair be used to ensure that need for the system is generally recognized through- out the maintenance department and that. vendor assistance • Review the machinery T/A schedule Maintenance Organization and Control for Multi-Plant Corporations 35 36 Machinery Component Maintenance and Repair Figure 2-4. Typical worklist