The air transport industry is considered as a forerunner and influential industry in the progress and development of any country and its status is one of the main and important indicators of development. Hegemony to the cost structure of airlines can manage the aircraft operating system on a systematic basis. The purpose of this research is to study and scrutiny the cost of aircraft maintenance in the airline and provide practical solutions to reduce these costs. To achieve this purpose, first, cost reduction methods were identified by studying documents and libraries and research background. Then a questionnaire was developed by Delphi method with a range of 5 Likert options and was distributed in 3 stages among 20 experts of airlines and cost reduction strategies were identified using SPSS software. Then, in order to prioritize the identified solutions, a hierarchical analysis questionnaire was prepared and distributed among the skilled staff of an airline. The results of the questionnaires were analyzed in Expert Choice software and the strategies were prioritized in four dimensions: structure, manpower, technology and budgeting. Finally, according to the research results, applicable solutions were presented based on 4 dimensions.

With the evolution of technology, the maintenance of sophisticated systems is of concern for system engineers and system designers. The maintenance cost of the system depends in general on the replacement and repair policies. The system replacement may be in a strictly periodic fashion or on a random basis depending upon the maintenance policy. At failure, the repair of the system may be performed perfectly or minimally associated with some probability. When perfect repair is done, it makes the system as good as the new one. In case of minimal repair, it returns to the working condition of the system at the time of failure. In the present paper, we study the replacement policies for the system wherein minimal or perfect repair is done at the time of failure. The expressions for s-expected cost for the system with replacement and minimal or perfect repair are evaluated. The maintenance costs are discussed for various policies. Numerical simulation is performed to validate the analytical results.

Introduction. The purpose of this study was to assess the health service cost of peritoneal dialysis (PD) delivered at home in Iran in comparison with hemodialysis.Methods. Cost and patient data were collected in 2006 and from April 1 to May 31, 2007, respectively. The reference year for the value of USD for different mentioned costs was 2006(1 USD=9188 Iranian Rial, local currency, 9.2006). The itemized description of related expenses are as follows: 1-Building costs:10 square meters for each 10 dialysis patients in the unit (each 40 square meters of common space of hospital monthly rent 3million Rials) 2-Drugs:Twelve vials of erythropoetin 2000 U monthly & Two vials of Venofer each month 3-Physician & Nurse:Once amonth visit by nephrologists, monthly salary of nurse is distributed according to 20 patients/ nurse ratio 4-Paraclinic test: Routines monthly, Viral check (HBV, HCV, HIV) biannually, PET, PTH, albumin, iron store tests every 3 months 5-Imaging:Chest X-ray, KUB, kidney sonography once a year. Results. The health care sector costs associated with catheterization and first educational period were 499.2 US$ and 79.3 respectively. The cost of maintenance of CAPD per month was 1040.3 USD per month. Most of the total maintenance expenditure was made up of medical supplies (78.6%), with solutions as the major cost driver. Staff salaries represented 2.8% of the cost and capital costs were negligible. Monthly costs in the category of case level (USD): 1-Drugs (erythropoetin, calcitriol, parenteral iron, etc.): 162.6 (15.6%) 2-Lab investigation: 9(0.9%) 3-Imaging: 3.1(0.3%) 4-related suppl ies (cap, clamps solut ion, drugs) : 818.5(78.6%) 5-Equipments (medical and non-medical): 9.5(0.9%). Monthly costs in the category of unit level (USD): 1-Physician (PD maintenance visits): 7.5(0.7%) 2-Nurse (PD maintenance visits): 21.8(2.1%) 3-Building replacement costs: 8.2(0.8%) Monthly costs in the category of hospital level (USD): 1-Central administration: hospital, nursing administration, accounting, information services, capital equipment and depreciation, construction and redevelopment: 0.09(0.1%).Conclusion. These findings are important as we know that the cost of maintenance of HD per month was 1025.3 USD per month which was estimated with the assumption of 3 shifts and full chairs which is not happening most of the time. This fact emphasizes on the fact that a major attempt should be made to increase peritoneal dialysis coverage as in many centers we cannot keep all chairs full for even 2 shifts, especially in some vast areas. In addition to the costs imposed on the health system sector, transportation to dialysis units imposes significant costs on society in terms of production losses due to the commute of patients and accompanying person. It is highly recommended to place initial focus on this strategy and reduction of cost of solutions to save resources.

Offering Maintenance Service Contracts (MSCs) for production equipment can be a good source of revenue for theProviders of these services. To do this, designing an optimal MSC with a minimum price will be of great interest to service providers. In this paper, the effect of conducting periodic preventive maintenance on the failure process of a given equipment item and its corresponding cost are studied. Assuming minimal repair at failure with a random repair cost, the expected cost of maintenance service is estimated. Due to the time delay between selling the contract and paying the repair bills, the time value of service cost at the time of selling the contract is derived. Then, the cost-plus approach is used to determine the price of the MSC. In the presented model, the service provider determines the number of preventive maintenance and the improvement level to minimize the expected price of the MSC. A numerical example with comprehensive sensitivity analysis is presented to illustrate the model and its parameters' effect. The result shows that the presented model helps the service provider to design an MSC with a minimum price while assuring the profit margin.

The model in this study was created to apply a new and functional model for prediction of IT maintenance cost of system downtime by using artificial intelligence method in contrast of other research techniques in IT cost measuring. The estimation is based on the measuring of IT services availability. In this model, ANFIS was developed for quantifying Information Technology Generated Services (ITGS) perceptible by business users. In addition, it was used to forecasting IT cost related to system maintenance that it can help managers for future and constructive decision. This model has been applied and tested prediction technique by ANFIS in MATALB fuzzy toolbox by previous large volume of data gathering from IT cost factors, ITGS, and associative cost in order to building pattern, tuning and training this model well. First of all, the model was fully developed, stabilized, and passed through intensive training with large volume of data collected in one of the organization in Iran. In first phase, it can be possible to feed a specific period of data into the model to determine the quantity of services (ITGS), and in second phase, their related maintenance cost can be predicted. ANFIS learning technique predicted maintenance cost of measured services availability which it was totally provided with first quantifying services in a specific time period. Having an operational mechanism for measuring and quantifying information technology services tangible by users for estimating their costs is contributed to practical accurate investment. Some components have been considered and measured in the field of system maintenance. The main objective of this study is prediction the amount of investment for maintenance of entire ITGS by extraction and considering the factors affecting the software maintenance cost help to estimate the cost and reduce it by controlling the factors.

The bridges as important links are connected all road networks and railways That a huge investment is needed to build them. In addition, bridges are considered as important points of vital arteries. If the bridges due to old age, exhaustion, overload, weather conditions, natural disasters and etc. destroyed, repair works are much more costly than the budget needed for the maintenance of them. Available budgets for reconstruction and maintenance, usually is not enough to maintain a constant state throughout the lifetime of the bridges. Due to the large number of bridges and high maintenance costs, it is not possible to repair and pay for maintenance of bridges simultaneously. In this study, the life cycle cost is calculated based on maintenance period of railway using multi-objective particle swarm optimization algorithm. Sensitivity analysis, furthermore, is done on deterioration rate and reduction of deterioration rate and effect of these parameters on system performance are analyzed.

This paper studies a maintenance policy for a system composed of two components, which are subject to continuous deterioration and consequently stochastic failure. The failure of each component results in the failure of the system. The components are inspected periodically and their deterioration degrees are monitored. The components can be maintained using different maintenance actions (repair or replacement) with different costs. Using stochastic regenerative properties of the system, a stochastic model is developed in order to analyze the deterioration process and a novel approach is presented that simultaneously determines the time between two successive inspection periods and the appropriate maintenance action for each of the components based on the observed degrees of deterioration. This approach considers different criteria like reliability and long-run expected cost of the system. A numerical example is provided in order to illustrate the implementation of the proposed approach.