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

Issue 26, April 2003

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

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Hot Topics  
ReliaSoft's Alternate Ranking Method 
When analyzing interval data, it is commonplace to assume that the actual failure time occurred at the midpoint of the interval. To be more conservative, you can use the starting point of the interval or you can use the end point of the interval to be most optimistic. Weibull++ allows you to employ ReliaSoft's ranking method (RRM) when analyzing interval data. Using an iterative process, this ranking method is an improvement over the standard ranking method (SRM). This article presents an example using the two-parameter Weibull distribution to illustrate how this method is employed. This method can also be easily generalized for additional models. 

To read more, see 

Reliability Basics  

Relationship Between Availability and Reliability
Availability is defined as the probability that the system is operating properly when it is requested for use. In other words, availability is the probability that a system is not failed or undergoing a repair action when it needs to be used. At first glance, it might seem that if a system has a high availability then it should also have a high reliability. However, this is not necessarily the case. This article will explore the relationship between availability and reliability and will also present some of the specified classifications of availability.

To read more, see 

Tool Tips  
  • When conducting analysis using the General Log-Linear life-stress relationship in ALTA 6, how do I specify the stress relation for each selected stress column?

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Latest Software Updates
Updates for Weibull++, Weibull++ MT, ALTA and BlockSim have been released recently. To determine the compile revision of the application on your computer, select About from the Help menu.


Application Date Created Version


Weibull++ 6 3/24/03 6.0.10
Weibull++ 6 Update 3/24/03 Service Release 6.0.10
Weibull++ 6 MT 3/24/03 6.0.10/6.1.7
Weibull++ 6 MT Update 3/24/03 Service Release 6.0.10/6.1.7


ALTA 6 3/31/03 6.0.11
ALTA 6 Update 3/31/03 Service Release 6.0.11


BlockSim 6

4/7/03 6.0.5

BlockSim 6 Update

4/7/03 Service Release 6.0.5
Hot News
* ReliaSoft Corporation Celebrates our 10th Year Anniversary - On April 30th, 1993 Pantelis Vassiliou, ReliaSoft's President and CEO, compiled his Weibull++ software. Today, ReliaSoft Corporation is the industry leader in reliability engineering R&D, software and services that combine the latest theoretical advances with essential tools for the practitioner in the field. Mr. Vassiliou shares his personal "Ten Year Retrospective."
* Xfmea is scheduled for release in April ($1995) - While there is time, you can still order Xfmea before the official product release date for a discounted price of $1595! This software has been designed to facilitate the FMEA/FMECA process and provide flexible data management and reporting capabilities. For more information, please visit:
* ReliaSoft's New Agreement with Maintain-IT - ReliaSoft is pleased announce a new international sales/support agreement with Maintain-IT. 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 on May 19 - 23, 2003, which utilizes ReliaSoft's BlockSim 6 and Weibull++ 6 software.
* New Free Tool at - ReliaSoft's RDA Utility for recurrent-events data analysis and plotting has been added to the free software tools on our Reliability Resources Web site,
* Special Thanks to the American Trucking Association - We enjoyed presenting at the 2003 Annual Meeting and Transportation Technology Exhibition last month in Ft. Lauderdale, FL. Thanks to everyone who received us so warmly.
* Training Around the World - Check for ReliaSoft Training within your region of the world by using our International Seminar Locator.
* Calendar of Public Events:


Quality Expo International 2003 - ReliaSoft will be in Chicago, IL April 15 - 17, 2003 to participate in this annual trade show geared towards manufacturing and quality professionals. ReliaSoft will be at booth 18062 in the exhibition hall where you can get information and demonstrations of ReliaSoft's products and services. For more details on this event, please visit:
QALT Boot Camp Training Seminar - April 30 - May 2, 2003 in Tucson, AZ. This intensive three day course covers advanced topics, concepts and applications of quantitative accelerated life testing (QALT) analysis and ReliaSoft's ALTA PRO software. For more information, see Remember that registered users of the ALTA PRO software can attend this seminar at no cost.
- May 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 - featuring experts and practitioners from both academia and industry. This symposium 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 reliability 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 once again ReliaSoft will be providing training classes for GM employees at the General Motors Knowledge Center in Warren, Michigan. Life Data Analysis and Accelerated Life Test Analysis will be the primary topics. Course dates are June 2 - 5, 2003. For more information, please contact Dennis Walters, GM Training Coordinator, at 248-684-3579. Class size is limited. GM suppliers should check with GM for class availability.
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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