In this issue:

Issue 74, April 2007

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

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Hot Topics

Using Duty Cycles in System Reliability Analysis
Components of a system may not operate continuously during a systems mission, or may be subjected to loads greater or lesser than the rated loads during system operation. To model this, a factor called the "duty cycle" is used. The duty cycle can also be used to account for changes in environmental stress, such as temperature changes, that may affect the operation of a component. The use of duty cycles in reliability modeling, especially in system reliability modeling and analysis, provides additional flexibility for the analyst. This article explains how to perform analysis using duty cycles in BlockSim 7.

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Reliability Basics

Introduction to the Generalized Eyring Life-Stress Relationship
When analyzing accelerated test data obtained from tests that involve multiple stress types, it is often assumed that the different stresses are independent and do not interact. The Hot Topics article in Issue 53 of Reliability HotWire described a methodology for analyzing the significance of interactions among different stress types. This article presents a life-stress relationship that is often used to analyze data obtained when temperature and a second non-thermal stress (e.g. voltage) are the accelerated stresses of a test and their interaction is also of interest. This relationship, called the generalized Eyring relationship, is available in ALTA 7 PRO.

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Tool Tips
  • How can I tell where a maintenance policy is assigned in a BlockSim 7 project?

  • How are Stress Profiles managed in ALTA 7 PRO?

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Latest Software Updates
A new version of ALTA (7.5.1) is now available. In addition, a new service release is now available for Weibull++ (SR 7.5.1). To determine the compile revision of the application on your computer, select About from the Help menu. More Software Downloads...


Application Date Created Version
Weibull++ 7    
Weibull++ 7 3/16/07 7.5.1
ALTA 3/16/07 7.5.1
Hot News
* ARS Lineup for 2007 - This year's series of International Applied Reliability Symposia begins next week in Frankfurt, Germany. Each event will be open for registration right up to the day of the event, but planning ahead typically helps. Sign up online or call your nearest ReliaSoft office today: Here is the official 2007 ARS schedule-- we hope to see you there!

International Applied Reliability Symposium       CRP Credits: 1

April 11 - 13, 2007 Frankfurt, Germany
April 19 - 20, 2007 Chennai, India
May 9 - 11, 2007 MG, Brasil
June 20 - 22, 2007 San Diego, California
October 25 - 26, 2007 Singapore
* MSMT this Month We still have seats available for our Master the Subject Master the Tools Foundations Seminar (RS401, RS402, & RS403). It will be held in Tucson, Arizona April 23 - 27. Due to the popularity of the course and the destination (few can resist Tucson, AZ in April!), this particular seminar has filled to capacity in the past. For those seriously considering this event, please make your reservations early to avoid scheduling issues. Click here for additional information:
* Baker Hughes Corporate Partner License - Baker Hughes has demonstrated its total commitment to reliability engineering practices by recently becoming an official ReliaSoft Global Corporate Partner. This agreement provides all Baker Hughes employees around the world with full unlimited access to all stand-alone products offered directly by ReliaSoft as well as access to all ReliaSoft training material. Welcome aboard, Baker Hughes! Learn more about ReliaSoft's Corporate Partner License option at
* Middle East Seminar - ReliaSoft's Middle East partner, Industry Automation Consultancy & Services (IACS), will be offering reliability training May 13 - 17, 2007 in UAE. This MSMT Foundations Seminar will be held at the Hilton Abu Dhabi hotel, (+) 971-2-6811900. For more information or to sign up, please contact IACS.
Public Training Event Calendar
April 2007
April 19 - 20, 2007: International Applied Reliability Symposium in Chennai, India
April 23 - 27, 2007: MSMT Foundations in Tucson, Arizona
May 2007
May 7 - 11, 2007: MSMT Foundations in Singapore
May 9 - 11, 2007: International Applied Reliability Symposium in MG, Brasil
May 16 - 18, 2007: RS 521 Advanced QALT in Tucson, Arizona
May 16 - 18, 2007: RS 511 Adv. Reliability Growth Analysis in Tucson, Arizona
May 31 - June 1, 2007: RS 480 Reliability Centered Maintenance in Tucson, Arizona
June 2007
June 4 - 8, 2007: RS 540 Repairable Systems Analysis in Tucson, Arizona
June 11 - 15, 2007: MSMT Foundations in Frankfurt, Germany
June 20 - 22, 2007: International Applied Reliability Symposium in San Diego, California
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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