Sharif Digital Repository

The simultaneous planning of the production and the maintenance in a flexible manufacturing system is considered in this paper. The manufacturing system is composed of one machine that produces a single product. There is a preventive maintenance plan to reduce the failure rate of the machine. This paper is different from the previous researches in this area in two separate ways. First, the failure rate of the machine is supposed to be a function of its age. Second, we assume that the demand of the manufacturing product is time dependent and its rate depends on the level of advertisement on that product. The objective is to maximize the expected discounted total profit of the firm over an... 

This article introduces a methodology to integrate fuzzy multiattribute decision making (FMADM) and fuzzy simulation. According to this method, a fuzzy simulation method is applied to study the effect of different alternative on system's performance and decision criteria taking into account fuzzy inputs. Using a fuzzy analytical hierarchy process (FAHP) and the results of fuzzy simulation, a FMADM is conducted to select the best alternative. This article introduces how to incorporate fuzzy set theory with discrete-event simulation in order to model uncertain activity duration in simulating a realworld system, especially when insufficient or no sample data are available. A case study is... 

Purpose - This paper aims to address the capability of reliability-centered maintenance (RCM), which is a preventive maintenance design tool. Design/methodology/approach - A model named Plant Function Deployment (PFD) is developed, in which the methodology of quality function deployment (QFD) is added to RCM to improve RCM capability in preserving the functions of the plants. Findings - The objective of preserving the plant functions with least resources, in RCM, is attained more efficiently if the methodology of QFD is added to RCM. Practical implications - PFD is a model for designing a preventive maintenance program which uses RCM and QFD methodologies. PFD organizes all the important... 

Preventive pavement maintenance methods such as slurry seals are cost-effective treatments that increase the longevity of pavements. The incorporation of recycled materials such as reclaimed asphalt pavement (RAP) into asphalt pavement helps to further reduce costs and energy consumption. The present research studied the feasibility of incorporating RAP into slurry seal mixtures or RAP slurry seals. Two slurry seal mixtures containing cement and hydrated lime as fillers were tested. The first mixture comprised slurry seal made with virgin aggregate and the second used RAP as the aggregate. The wet track abrasion test (WTAT) and loaded wheel test (LWT) were conducted to evaluate the... 

The increasing use of power electronic equipment and the importance of their continuous and correct operation have attracted remarkable attention to the condition monitoring of power electronic converters. Since capacitors are the leading cause of power electronic converters failure, this paper attempts to attain a solution to monitor the condition of the DC-link capacitor in a three-phase back-to-back converter using the stimulated measurable transients. The proposed method works based on the temporary change of switching logic and the measurement of the DC-link voltage and converter input phase current transients. By processing the measured signals, the capacitance of the capacitor is...