A novel methodology of risk assessment for railway freight wagons

This study proposes a new methodology for the accurate risk assessment of railway freight wagons that has real-world applications in the operation and maintenance of freight vehicles. The paper specifically focuses on the analysis of posterior reliability calculation methods using Weibull’s reliability model to calculate reliability indicators by which the probability of occurrence of individual failures can be estimated. The consequences of failure are calculated through an existing system from the General contract used for freight wagons (AVV). The formula for calculating the risk value is based on a classical risk theory, where the risk is defined as a combination of the occurrence of a negative phenomenon and the severity of its consequence. The reasoning for this approach was in an effort to maintain simplicity and clarity for potential users in practice. This is based on the information gathered in examining the current state of risk management in the sector of railway vehicles in Slovakia. The data used for risk calculations were taken from a maintenance workshop in Slovakia to provide a realistic picture of the failure rates of freight wagons. The proposed methodology uses historical data for prediction of reliability for the next years. Based on the reliability being a function of time, the risk associated with it is variable, increasing with time. These findings have broader implications for the maintenance systems taken appropriate maintenance actions necessary with respect to increased risk

Simulation as Logistic Support to Handling in the Warehouse: Case Study

Manipulation processes represent an important part of the material management in a company. These processes run inside a company and represent an integrated chain of material flow. The current situation regarding the material manipulation is evaluated using the manipulation indicators which may serve as the basis for manipulation system rationalisation designs. The present case study is focused on the determination of an appropriate number of forklift trucks in a given operation and consists of three sections. The introductory section deals with the evaluation of forklift activities while applying the selected analysis and the selected indicators. Analysis results subsequently served as a basis for the calculation. The calculated number of trucks must be properly verified; the verification should be focused on whether the given number of forklifts is actually sufficient for the performance of the current activities. The activities were verified while applying the simulation. A simulation model was created using the Technomatix Plan Simulation software

Model calculations of posterior reliability indicators for the proposal of the maintenance system

Designing the content and scale of maintenance of machines and equipment by a priori and posterior reliability methods in considered crucial to reducing the cost of the machine's life cycle, maintaining high operational readiness and reducing the consequences of failures. In the presented paper, attention is paid to the analysis of the calculation methods of posterior reliability for calculation indicators of reliability and to the use of the specified Weibull model for reliability calculations. The obtained results are further developed for models of optimal process calculations to perform scheduled maintenance interventions. Calculations of the other RAMS (reliability, availability, maintainability and safety) indicators that are critical to the design of an optimal engineering design with regard to maintenance and which do not receive sufficient attention in technical practice are also assessed

Model calculations of posterior reliability indicators for the proposal of the maintenance system

Designing the content and scale of maintenance of machines and equipment by a priori and posterior reliability methods in considered crucial to reducing the cost of the machine's life cycle, maintaining high operational readiness and reducing the consequences of failures. In the presented paper, attention is paid to the analysis of the calculation methods of posterior reliability for calculation indicators of reliability and to the use of the specified Weibull model for reliability calculations. The obtained results are further developed for models of optimal process calculations to perform scheduled maintenance interventions. Calculations of the other RAMS (reliability, availability, maintainability and safety) indicators that are critical to the design of an optimal engineering design with regard to maintenance and which do not receive sufficient attention in technical practice are also assessed

FMECA analysis of thermal deburring machine EXTRUDE HONE TEM P-350

This study investigates FMECA analysis and its potential use in improving the reliability and maintenance of the thermal deburring machine in a manufacturing company located in Slovakia. In the beginning, an overview of the FMEA/FMECA methods and their utilization for increased reliability are discussed. As a practical solution, the deburring machine EXTRUDE HONE TEM P-350 was chosen. Functions of its systems and components, thermal deburring process, its characteristics and in practice application are described. Maintenance policy in the company and the current state of maintenance of the machine are also presented. In addition, the study includes failure analysis which evaluates the riskiest systems of the machine. One element, hydraulic unit, is a subject for the FMECA analysis which envisions the assessment of the current failure modes using risk priority number (RPN) and proposals of prevention and detection action reducing the level of RPN. The final section focuses on influencing and improving maintenance and summarizing the potential benefits of FMECA Analysis for company and machine operation

Use of risk assessment methods in maintenance for more reliable rolling stock operation

Operation of the rolling stock is associated with a number of risks. The consequences of failures are sometimes very serious - safety or the environment, sometimes only economic. A significant factor affecting the safe operation of railway vehicles is maintenance. The paper presents methods of risks assessment and possibilities of their reduction in design, operation and maintenance of railway vehicles. Special attention is given to the new "silent brakes" and safety related issues for freight wagons