Michal Vintr

Estimate of Warranty Costs Based on Research of the Customer's Behavior

This paper deals with an estimate of costs when two-dimensional warranty is granted. The paper includes a procedure of estimation of costs of the warranty based on a research of behavior of the customers. This procedure is applicable for an initial estimate of warranty costs or analysis regarding the extent of warranty to be provided. The practical use of the proposed method is demonstrated by an example of the estimates of warranty costs of a lower medium class personal car manufactured in Czech Republic. For this paper, several hundred users of the said car type were interviewed to identify the average mileage by a typical car user during one year of operations. The result of survey were assessed statistically and used to analyze the an influence of changes of basic parameters of the warranty, namely guaranteed calendar time of use and guaranteed time of operation, on the warranty costs.

Does appropriate software support for target identification exist

The paper deals with the evaluation and the selection of available software tools that can be utilized in solving problems related to the identification of the targets of malicious acts. The paper presents grant project requirements that focus on the development of methods for the target identification in the field of nuclear energy and critical infrastructure in the Czech Republic. The main requirements are related primarily to the modeling of unacceptable effects of malicious acts. Based on the project purposes, the specific requirements for software support for targets identification are defined. In the next step, the available methods and techniques such as event trees, fault trees and attack trees are introduced. After that there is a summary of available software tools focused on modeling and solving event, fault and attack trees. Individual software tools made by reputable producers are characterized in detail. Finally the paper compares the capability of available software tools with the specified requirements.

FMEA used in assessing warranty costs

This article presents a proposal of procedure that enhances standard failure mode and defect analysis (FMEA) and at each mode of failure it analyses other information that are necessary for estimation of warranty costs. In addition to standard analyzed information, at each failure mode it further evaluates an assumed number of a given type of failure during a warranty period, method of its repair, its labor consumption and costs needed for spare parts and material. It also presents a model that based on these data enables to carry out an estimate of warranty costs of a product as a whole.

Evaluation of physical protection system effectiveness

The ability of physical protection system (PPS) to withstand a possible attack and prevent an adversary from achieving his objectives is generally characterized as PPS effectiveness. The evaluation of effectiveness serves then as a basis for assessing whether a relevant PPS meets an intended aim. The article presents the selected results of an extensive analysis tackling the present state of PPS system effectiveness evaluation. There has been determined the achieved state of the development of a PPS efficiency evaluation theory, and also the possibilities of practical application of known algorithms, analyses, models, program products, tests and exercises which might be used for evaluating the PPS effectiveness. The authors of the paper have proposed that a couple of ways can be selected to develop these methods more when following the results of the performed analysis.

Contribution to Rolling Bearing Reliability Modeling

Rolling bearings are usually considered to be non-repaired items the reliability of which is characterized by mean time to failure, or so called basic rating life. Reliability describes these parameters well in case the bearings are used in operation up to the very time the failure occurs, or during the time corresponding with basic rating life. In case of railway applications the bearings are often used in large groups and are preventively replaced after much shorter operating time as compared with their basic rating life. In the article there is a model which enables us to describe the bearings reliability in this specific case and to specify a number of failures which might be expected from a group of bearings during operating time, or to determine mean operating time between failures of bearings.

Evaluation of Product Reliability during Warranty

The paper deals with the possibility of assessing product reliability in the case a producer has no data about the behavior of products in service, and the only available thing is the information on warranty claims. The suggested method of reliability assessment utilizes the information on the number of products manufactured, the date when their service started, and the number of claimed products during a warranty period. An example of method practical application is presented too.

Warranty Data Evaluation

The article deals with a possible way how to monitor and evaluate warranty date. Tools that allow the current development of warranty costs and related indicators to be monitored and evaluated are outlined in the article. The tools proposed are applicable to the continuous (periodical) evaluation of real development and the detection of possible deviations, which can occur when comparing real and predicted development warranty data.

Warranty Costs Assessment for Automotive Applications

The article deals with current problems of warranty costs in automotive applications. The two-dimensional warranty widely used in automotive industry is presented. The relationship between warranty costs and product reliability is also presented. The article analyses problems with estimation of a number of failure occurrence over a warranty period and estimation of costs related to repair failures. The mathematical model enables to predict warranty costs for two-dimensional warranty is presented. The article also deals with problems of estimation of an instant of warranty period expiration and demonstrates its estimation on an example of a vehicle.

Warranty costs monitoring

The article deals with problems related to providing the warranties. The tools that allow continuously monitor and evaluate current development of warranty costs and related indicators are presented in the article.

An assessment of mean time between failures for a group of rolling bearings

Rolling bearings are usually considered to be non-repaired items the reliability of which is characterized by mean time to failure, or so called basic rating life. Reliability describes these parameters well in case the bearings are used in operation up to the very time the failure occurs, or during the time corresponding with basic rating life. In case of railway applications the bearings are often used in large groups and are preventively replaced after much shorter operating time as compared with their basic rating life. In the article there is a model which enables us to describe the bearings reliability in this specific case and to specify a number of failures which might be expected from a group of bearings during operating time, or to determine mean operating time between failures of bearings.