Reliability HotWire: eMagazine for the Reliability Professional
In this issue:

Issue 27, May 2003

*Hot Topics
*Reliability Basics
*Tool Tips
*Latest Software Updates
*Hot News
*From the Edge
*Contribute to HotWire

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Hot Topics  
Using Reliability Block Diagrams to Analyze Dependent and Independent Failure Modes 
When thinking of a reliability block diagram (RBD), the application that most often comes to mind is the analysis of a system based on the component reliabilities. You can also use the same methodology for a single component and its associated failure modes. In analyzing this scenario, both independent (i.e. if one mode occurs, the rest are not more likely to occur) and dependent modes (i.e. if one mode occurs, the rest are more likely to occur) can be included. To illustrate this, a component with multiple primary modes as well as multiple secondary modes (sub-modes) will be considered. In addition, both independence and dependence will be utilized.

To read more, see 

Reliability Basics  

Throughput Analysis (Part I)
Throughput analysis allows you to analyze a reliability block diagram (RBD) such that each component within the system is designed to process (make) something while it is in operation. Part I of this article will introduce some throughput metrics and terminology. In addition, some basic analysis using throughput and how this can be accomplished in BlockSim 6 will also be discussed. Part II will be presented in next month's issue of the HotWire and will explore more complex scenarios regarding throughput analysis.

To read more, see 

Tool Tips  
  • In Xfmea, how can I quickly edit the records in the FMEA Hierachy without having to open and close the properties window for each record?

  • What is the purpose of Xfmea's Check Analysis utility? 

To read more, see 

Latest Software Updates
Xfmea (1.0.1) has now been released. In addition, new service releases for BlockSim (SR 6.0.6) and MPC (SR 3.0.8) are also available. To determine the compile revision of the application on your computer, from the Help menu select About.


Application Date Created Version
Xfmea 4/30/03 1.0.1
Xfmea Update N/A N/A
BlockSim 6 4/28/03 6.0.6
MPC 3 5/1/03 3.0.8
MPC 3 Update 5/1/03 Service Release 3.0.8
Hot News
* Xfmea was officially released on April 30th!!! - Now available for purchase and evaluation, Xfmea has been designed to facilitate the FMEA/FMECA process and provide flexible data management and reporting capabilities. Pre-release orders have been filled. For more information, please visit our Website at or contact the sales team directly.
* ReliaSoft's Consultants Meet a Variety of Needs - You all know ReliaSoft as a world class developer of reliability analysis tools. We also have an expert team of consultants who are ready to assist you in the areas of quality and reliability engineering. ReliaSoft consultants can provide expertise in any of the following areas:
  • Complete Reliability Program Development
  • Test and Experiment Design
  • Data Analysis and Reporting
  • Developing, Evaluating and Communicating Reliability Requirements
  • Equipment Reliability, Maintainability and Availability Assessment
  • Theoretical Development

We realize that under today's economic conditions, company reliability resources are stretched to the limit and that you may not have the time to take on another project. Whether you have a large project you can't find time for or merely need another set of eyes to review your analysis or report, please consider giving us a call. We would be happy to discuss your requirements and promptly provide you with a cost and time estimate for completion of the project. Consultant biographies and client lists are available at

* Special Thanks to the Quality Expo International Attendees - We enjoyed the attention we received at our booth a few weeks ago in Chicago, especially your spirited interest in Xfmea. Thank you for stopping by to visit with us, checking out the software and gathering information related to our various products and services.
* UK Company Utilizes ReliaSoft Tools for Public Training - Maintain-IT is a UK-based company that offers consultancy support in many areas of maintenance management, primarily to oil and gas, chemicals, beverage and manufacturing industries worldwide. Maintain-IT will host their Practical Reliability Workshop May 20 - 22, 2003 utilizing ReliaSoft's BlockSim 6 and Weibull++ 6 software.
* Training Around the World - Check for ReliaSoft training that is available within your region of the world by using our International Seminar Locator.
* Calendar of Public Events:


Rio de Janeiro International Reliability Symposium - During this symposium, held May 8 - 9, 2003 in Rio de Janeiro, Brazil, engineers will be examining current reliability practices, issues and applications through lectures and discussions. This symposium features experts and practitioners from both academia and industry and is sponsored by ReliaSoft Brasil. View symposium details at
Master the Subject, Master the Tools Training Seminar for life data analysis, accelerated life data analysis and system analysis: May 19 - 23, 2003 in Tucson, AZ. For more information, see
June Reliability Training Courses at the GM Knowledge Center - We are pleased to announce that ReliaSoft will be providing training classes for GM employees at the General Motors Knowledge Center in Warren, Michigan once again. Life Data Analysis and Accelerated Life Testing Data Analysis will be the primary topics. Course dates are June 2 - 5, 2003. For more information please contact Dennis Walters, GM Training Coordinator, at +1.248.684.3579. Class size is limited. GM suppliers should check with GM for class availability.
From the Edge

In addition to the monthly Reliability HotWire, ReliaSoft publishes Reliability Edge, a printed journal that includes articles and information related to the field of reliability engineering. Articles of interest in the current edition:

  • Graphical Analysis of Repair Data - This article presents a simple and informative plot for analyzing data on numbers or costs of repeated repairs of a sample of products. The plotting method provides a nonparametric graphical estimate of the mean cumulative number or cost of repairs per unit versus age. This article presents the basic population model for such repeated events data and its mean cumulative function (MCF). Using a typical data set for repair data (transmission repair data from cars on a preproduction road test), this article shows how to calculate and plot a sample estimate of the MCF for data from products with a mix of ages. This is followed by an explanation of how to use and interpret such plots. See

  • Developing a Reliability Benchmark Survey - The University of Warwick (United Kingdom) is currently conducting a detailed and far-reaching survey of reliability practices, the "Benchmark Survey of Timely and Cost- Effective Application of Reliability Techniques." Companies world-wide and across all industries are called upon to participate. The survey has been designed to investigate the contextual factors that lead a project to choose specific reliability techniques. It attempts to benchmark reliability activity according to the speed that reliability techniques deliver useful output, the quantity and cost-effectiveness of that output, its authority and accuracy and the uses to which the output contributes. See

Contribute to HotWire

Contributions Welcomed
As always, your feedback and contributions are appreciated. ReliaSoft is able to provide the most user-friendly reliability software packages and support because we listen to our customers. This applies to our newsletters and publications as well. We welcome any suggestions or contributions you may have for Reliability HotWire. If you have a topic or article that you think would be useful to the readers of Reliability HotWire, feel free to contact us.

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