Maintenance scheme

Maintenance schemes and standards require defined intervals between shutdowns for invasive inspections. During a shutdown, the installation is opened and inspected. This is usually the... 

Protective scheme Initial cost ( /0 Maintenance scheme Cost of each maintenance ( /t) Aggregate cost over 24 years ( /t)... 

Expenditure on corrosion prevention is an investment and appropriate accountancy techniques should be used to assess the true cost of any scheme. The main methods used to appraise investment projects are payback, annual rate of return and discounted cash flow (DCF). The last mentioned is the most appropriate technique since it is based on the principle that money has a time value. This means that a given sum of money available now is worth more than an equivalent sum at some future data, the difference in value depending on the rate of interest earned (discount rate) and the time interval. A full description of DCF is beyond the scope of this section, but this method of accounting can make a periodic maintenance scheme more attractive than if the time value of money were not considered. The concept is illustrated in general terms by considering a sum of money P invested at an... 

Revised and advanced in-use compliance testing/inspection and maintenance schemes, involving OBD checks to control emissions over the lifetime of the vehicle. 

Typical activities associated with the periodic review phase for instramentation inclnde establishing a recalibration program and conducting rontine maintenance activities as part of a plaimed preventive maintenance scheme. All maintenance activities mnst be carried out under a formal change control procedure and any associated testing mnst be fnlly documented nsing test record sheets. 

The design period (life) is recommended to be taken as 40 years for all sections where traffic is heavy for less heavily trafficked sections or major maintenance schemes a 20 years design period may be appropriate. 

The most simple preventive maintenance scheme consists in replacing the system. This boils down to assuming that, after maintenance, the system is As Good As New (AGAN). Having brought the system back to i = 0, the same failure rate evolution in time is then considered for its future likelihood to fail. 

The results of a study of major maintenance schemes suggest that the effect of these schemes on all-purpose dual carriageways is to increase the personal injury accident rate by 14.5%. 

Obviously, not all possible details of plant maintenance can be comprised in a preventive maintenance scheme. A carefully considered choice must therefore be made as to what can and what cannot be included. 

Storing conditions that are unfavorable to micro-organisms are mainly low air humidity and/or low temperature. Also sealing to avoid micro-organic contamination is a well known method. The actual maintenance scheme necessary for a certain product depends on the product properties, the conditions under which it is used and the degree of hygiene one aims to reach. 

The success of any planned maintenance scheme is dependent on the skill of the staff and its conscientious application. Apart from the selection of competent people to carry out the work, in-house training is required to familiarise them with the installation and the planned maintenance scheme, and hopefully to inspire them with some enthusiasm for the task. This might be done by explaining the importance of preventive maintenance, their role in it and its relevance to the safety of the staff and economic success of the business. A training course might include ... 

The reasons for a planned maintenance scheme, including its economic justification. 

Establishing a maintenance scheme can fall on a number of responsible persons either individually or together. These include the employer or occupier of the premise or any other premises forming part of the building, or dependent upon contract terms of the owner or management company. 

Operating and maintenance costs cannot be predicted accurately because of the lack of knowledge and experience however, the information availiible [24] indicates that O and M costs may run as high as 4 mills/kwh in the first plants constructed. Difficulties associated with predicting O and M costs concern predicting component lifetimes, component repair/discard ratio, maintenance procedures, and downtime required for maintenance. Also, detailed design studies of various maintenance schemes are required before these various schemes can be fully evaluated. Based on present... 

The final decision of the optimal inspection period will depend heavily on the needs and operating culture of the owner/operator of the vessel. The implementation of such a regime on fishing vessels will be influenced by the operating circumstances of the equipment and other factors such as availability of expertise, position of vessel and sea conditions. However, should the conditions for implementation be favourable, delay-time analysis can be used to optimise the system s inspection maintenance scheme. 

The Road Safety Audit process can also be applied to existing roads, where they will be based on collision rates, police advice and speed measurements. Major maintenance schemes (but not routine periodic maintenance) may be subject to Road Safety Audit. 

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