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| In this issue: |
Issue 45, November 2004 |
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Reliability HotWire is a service of
ReliaSoft Corporation
To subscribe or update your e-mail preferences, go to
http://www.weibull.com/hotwire/index.htm
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Hot Topics |
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Bringing It All
Together
The construction or enhancement of a reliability
program will, by necessity, be specially adapted according to the specific
needs and structure of the organization. As is the case with many other
situations, "form follows function," and the form of the reliability program
will follow the function of the organization that is implementing it.
However, it is necessary to make sure that the information that is generated
by the reliability program is fed back throughout the organization so that
the maximum benefits of the program can be achieved. Instituting a
reliability program merely for the sake of having a reliability program will
ultimately be of no benefit to anyone. If the reliability program is not
feeding back useful information to all of the areas of the organization that
need it, it will eventually atrophy and become just a little-utilized
enclave of the larger organization. Of course, it is unlikely that an
organization that has gone to the trouble of implementing a high-efficiency
reliability program will allow such a program to wither and die, but it is
important to make sure that the reliability program's benefits reach all the
areas that it can.
To read more, see
http://www.weibull.com/hotwire/issue45/hottopics45.htm
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Reliability Basics |
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Common Shape Parameter Likelihood Ratio Test
In order to assess the
assumption of a common shape parameter among the data obtained at various
stress levels, the likelihood ratio (LR) test can be utilized. This test
applies to any distribution with a shape parameter. In the case of
ALTA 6, it applies to the Weibull
and lognormal distributions. When either of these is used as the underlying
life distribution, the shape parameter is assumed to be constant across
different stress levels (i.e. stress independent). This article shows
how to assess the validity of this assumption.
To read more, see
http://www.weibull.com/hotwire/issue45/relbasics45.htm
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Tool Tips |
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For the Weibull distribution, what is the difference between the
characteristic life and the mean life?
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When considering complex repairable
systems, what is the difference between the Weibull distribution and
the Power Law model?
To read more, see
http://www.weibull.com/hotwire/issue45/tooltips45.htm
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Hot News |
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51st Annual
Reliability & Maintainability Symposium (RAMS) -
ReliaSoft Corporation will be a Diamond Level Sponsor and a
participant at RAMS this winter. The event is scheduled for
January 24-27, 2005 at the Hilton Alexandria Mark Center in
Alexandria, Virginia. Topics related to Reliability,
Maintainability, Quality, Risk Management and Safety will be
addressed as engineers are exposed to state-of-the-art methods for
achieving their R&M objectives. For more information and an Advanced
Program, see http://www.rams.org. |
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Prediction
Software by ReliaSoft ReliaSoft is happy to announce new
developments! The finishing touches are being added to our standards
based reliability prediction software,
Lambda Predict. This
software will include MIL-HDBK-217, Bellcore (Telcordia), RDF 2000
and China 299B for the analysis of electronics and related
components plus NSWC-98/LE1 for mechanical components. It will also
ship with an extensive collection of pre-defined component
libraries. For more information on Lambda Predict, please visit
http://Predict.ReliaSoft.com.
If you are interested in receiving a demo upon software release
please let us know at
http://Predict.ReliaSoft.com/evaluation.htm. |
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International
Representation ReliaSoft recognizes that todays
engineering community is a global endeavor that requires cross
communication between different regions of the world. Therefore,
ReliaSoft continues to bridge the international gap by staffing and
partnering with local professionals in key locations. To the benefit
of non-English speaking countries, our regional offices are staffed
with multilingual representatives. Many offices have also begun
translating Web sites and various resources. If you have an
international colleague who could benefit from the reliability
engineering resources offered by ReliaSoft, then we encourage you to
seek out the professionals we have made available. Here is the
directory for all of ReliaSoft's official regional offices and
representatives:
https://www.reliasoft.com/about/contact-us. |
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Public Training Event Calendar
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November 2004 |
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- November 15 - 19:
MSMT
in Tucson, Arizona |
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- November 22 - 26:
MSMT
in Shenzhen, China
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Register through RS China |
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- November 29 -
December 3:
MSMT
in Singapore
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Register through RS Asia |
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December 2004 |
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- December 6 - 8:
QALT Boot Camp in Tucson, Arizona |
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- December 6 - 8:
Reliability Growth, Repairable System Data Analysis and RGA
in Tucson, Arizona |
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- December 6 - 10:
MSMT
in Melbourne, Australia
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Register through RS Asia |
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- December 13 - 17:
MSMT
in Penang, Malaysia
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Register through RS Asia |
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- December 20 - 22:
RS
401 in Shah Alam, Malaysia
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Register through RS Asia |
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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:
- Most complex systems, such as
automobiles, communication systems, aircraft, aircraft engine
controllers, printers, medical diagnostics systems, helicopters, train
locomotives, etc., are repaired and are not replaced when they fail.
When these systems are fielded or subjected to a customer use
environment, it is often of considerable interest to determine the
reliability and other performance characteristics under these
conditions. Areas of interest may include assessing the expected number
of failures during the warranty period, maintaining a minimum mission
reliability, addressing the rate of wear-out, determining when to
replace or overhaul a system and minimizing life cycle costs. In
general, a distribution, such as the Weibull distribution, cannot be
used to address these issues. In order to address the reliability
characteristics of complex repairable systems, a process is often used
instead of a distribution. The most popular process model is the Power
Law model. To view the entire article see:
http://www.ReliaSoft.com/newsletter/v5i1/repairable.htm.
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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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Copyright 2004
ReliaSoft Corporation, ALL RIGHTS RESERVED
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