Inspection and maintenance strategies

Regulation 4(2) of the Electricity at Work Regulations requires that as may be necessary to prevent danger, all systems shall be maintained so as to prevent so far as is reasonably practicable, such danger . Regular maintenance is, therefore, required to ensure that a serious risk of injury or fire does not result from installed 

Inspection and maintenance periods should be determined by reference to the recommendations of the manufacturer, consideration of the operating conditions and the environment in which equipment is located. The importance of equipment within the plant, from the plant safety and operational viewpoint, will also have a bearing on inspection and maintenance periods. The mechanical safety of driven machinery is vital and the electrical maintenance and isolation of the electrically powered drives is an essential part of that safety. 

Safe operating procedures for the isolation of plant and machinery during both electrical and mechanical maintenance, must be prepared and followed. All electrical isolators must, wherever possible, be fitted with mechanisms which can be locked in the open/off position and there must be a procedure to allow fuse withdrawal wherever isolators are not fitted. 

Working on live equipment with voltages in excess of 110 volts must not be permitted except where fault finding or testing measurements cannot be done in any other way. Reasons, such as the inconvenience of halting production, are not acceptable. 

Part of the maintenance process should include an appropriate system of visual inspection. By concentrating on a simple, inexpensive system of looking for visible signs of damage or faults, many of the electrical risks can be controlled, although more systematic testing may be necessary at a later stage. 

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Inspection and maintenance strategies should be reviewed and compared to acceptable standards and industry best practice to determine if these are sufficient to maintain/monitor integrity or if improvements are required. 

A plain line block section is modeled in this paper to evaluate inspection and maintenance strategies. According to the above modeling framework, a hierarchical CPN model is built to estimate derailment frequency, system availability and maintenance cost. The CPN model contains several parts component deterioration model, component working model, operation and accident model. 

Preventive maintenance provides more operational rehabihty however, it also involves higher inspection and maintenance costs, if the inspection strategy is appHed, or higher repair costs if the exchange strategy is applied. Which maintenance strategy will be applied depends on a number of factors, such as Hfespan, personnel structure etc, and will be determined by company management... 

Predictive maintenance. Predictive maintenance refers to maintenance based on the actual condition of a component. Maintenance is performed not according to fixed preventive schedules, but rather when a certain change in characteristics is noted. Corrosion sensors that supply diagnostic information on the condition of a system or component play an important role in this maintenance strategy. Preventive maintenance aims to eliminate unnecessary inspection and maintenance tasks, to implement additional maintenance tasks when and where needed, and to focus efforts on the most critical items. 

The Clean Air Act requires each state to adopt a plan, a State Implementation Plan (SIP), which provides for the implementation, maintenance, and enforcement of the NAAQS. It is, of course, emission reductions that will abate air pollution. Thus the states plans must contain legally enforceable emission limitations, schedules, and timetables for compliance with such limitations. The control strategy must consist of a combination of measures designed to achieve the total reduction of emissions necessary for the attainment of the air quality standards. The control strategy may include, for example, such measures as emission limitations, emission charges or taxes, closing or relocation of commercial or industrial facilities, periodic inspection and testing of motor vehicle... 

In order to achieve effective, safe, and reliable operation of all equipment in the inventory, the hospital uses interval-based inspections and preventive maintenance, corrective maintenance, or metered maintenance strategies. Model-specific strategies and preventive maintenance procedures developed for this equipment based on the risk stratification, the AHA Manual for Medical Equipment, manufacturer guidelines, and NFPA or ANSI standards. 

In this Final Rule, U.S. HUD sets forth seven strategies for lead paint or paint hazard evaluation and hazard reduction, varying in relative stringency from least to most (1) safe work practices during rehabilitation (2) ongoing lead paint maintenance practices to assure continued intact surfaces (3) visual assessment and paint stabihzation (4) risk assessment and interim controls (as defined above) (5) combined risk assessment and lead paint inspection with interim controls (6) risk assessment and abatement of lead paint hazards and (7) lead-based paint inspection and abatement via removal of aU lead paint. 

It is also obvious that the maintenance strategy has effects on the invitation to tender for the plant In case of the inspection strategy, additional investments for metrological recording are required. Furthermore, the delivery of spare and wear parts as well as possibly of complete aggregates has to be taken into consideration. 

For the purpose of the demonstration, a case study of a typical wind farm is defined. A detailed model is built that accounts for numerous operational, cost and maintenance parameters. The ApmOptimizer optimization modules are then implemented for optimizing the preventive maintenance, periodical inspections, condition-based maintenance, and spares levels. Starting from a baseline scenario, several optimization steps are investigated, following a typical RAM/LCC analysis assessment procedure Operational AvaUabiUty, Operational Downtime, Lifecycle O M Costs and produced Energy are used as the main metrics. The optimal maintenance strategy is obtained from an exact optimization process and not from Monte Carlo simulations that can provide only an approximate assessment for a user-inputted strategy. 

All the presented works give the model of optimal period between inspections estimation. However, they do not address the issues of selection of the type of maintenance strategy which should be use depending on the analysed technical system and its operational process. These issues are one of the scope of maintenance management systems or decision support systems developed in the analysed research area. For more information we recommend reading e.g. (Bojda et al. 2014, Laskowski and Bylak 2013, Vintr and Valis 2012). 

Maintenance strategies represent one of the many areas of maintenance research theory. Among the many listed models fulfill an important role in the maintenance system strategy is based on the control of main parameters of the model the so-called strategies to control the state of the system (called inspection maintenance, inspection and replacement models). Computational problem in this type of strategies is the selection of optimal moments inspecting the object that operating costs were minimal (Koucky Valis 2011). Overview of system status control models can be found, inter alia, in (Nowakowski Werbinska-Wojciechowska 2012). 

Within the risk control of industrial equipment, knowing the progress of the damage stage is crucial for selecting the strategies for maintenance, inspections, and checks, that is, the means to reduce the risk. 

In PM, maintenance activities are performed before equipment failure. PM involves the repair, replacement and maintenance of equipment in order to avoid unexpected failure during use. PM with inspection intervals is a commonly used maintenance strategy (Ben-Daya and Hariga (1998), Lofsten (1999), Crocker (1999)). The objective of any PM programme is to minimise... 

The plant engineer and his maintenance manager will establish whoever carries out the work, basic strategy, programming and procedures. Inspection checklists and record sheets are necessary for systematic location of critical elements/potential defects and setting out frequencies of inspection. Computers and work processors are an obvious aid to effective maintenance management. Inspection-based preventive methods are demonstrably cost effective. 

Visual and other non-intrusive examinations are an essential part of maintenance. This typically begins with an inspection plan that outlines the type and frequency of inspection. The anticipated damage mechanism and the probability determine the type of inspection. The frequency is determined by the consequences associated with the damage. The consequences and the probability together constitute the risk-based inspection (RBI) strategy. 

Airworthiness of civil aircraft depends upon a process by which a team composed of aircraft manufacturers, regulators, and one or more airlines predicts possible system failures. This process. Maintenance Steering Group 3 (MSG-3), considers possible failure pathways (e.g., in structures, controls, avionics) and for each pathway determines a recovery strategy. For structural failure, this may be replacement after a fixed service life, regular inspection to ensure detection, or an indication to crew of the malfunction. The concern here is with the reliability of the primary failure recovery system for aircraft structural inspection regular inspection to ensure detection. 

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