Failure is not an Option
Probability Plotting with or without Suspensions, Group or
non-Group data, Weibull
Maximum Likelihood Estimate, Weibull, Lognormal, Exponential,
Normal regression results, Three-Parameter Weibull Analysis and
Mixed Multi-modal analysis (as many modes as in your data can be
separated using DfRSoft's iterative method).
Also available small sample size Weibull-Bayesian ("WeiBayes")
MLE analysis as well as Bayesian method for Weibull
Regression Beta over-ride entry and Lognormal small sample size
sigma-over ride analysis.
Confidence bounds both
single-sided and two-sided options displayed graphically and
analytically. DfRSoft Best Predictor - which distribution is
best predictor of entered data. Excel friendly graphics interface –easily change
titles, scales, grid lines, copy and past to word documents…)
Distribution Shapes: Once a distribution key parameters are know
such as Weibull characteristic life and beta, then quick plots for the distributions
can be obtained over any time period for:
Exponential, Weibull, Lognormal, Normal. Simply enter the distribution key parameters. Plots
include, PDF, CDF, Reliability, and the Hazard Rate.
Alternately use the Reliability Statistics and Confidence area
for predictions (see description below).
Click to SEE (10 Min) VIDEO TUTORIAL ON RELIABILITY
PLOTTING IN DfRSoft
System Reliability Analysis:
Items in Series or Parallel, block
diagram entry. Special parallel units: N of K, Stand-By Units,
Parallel items with different FR and Repair Rates assessment. Work in either MTBF or failure rate units. System analysis
includes friendly block diagram entry format - simple transfer
to power point of word document via copy paste.
DfRSoft SYSTEM RELIABILITY ANALYSIS INSTRUCTIONAL VIDEO
Reliability & Quality Statistics and
Weibull, Lognormal, Normal, Exponential Distributions - with
This area allows user to make
prediction when distribution parameters are known. For example
given the Weibull characteristic life and beta, what percent
failure is expected at a certain time period. What are the
confidences around this value.
Discrete and Sampling
Chi Square, Standard Limits, Poisson and Binomial - with
Manufactures Predictions and/or MIL HDBK 217, 217+M, Telcordia…): A variety of
methods for detailed stress and parts count:
DfRSoft offers a corporate manufacturers’ MTBF detailed stress
prediction model with part failure rates library from companies
like Analog devices, National Semiconductor, TI etc.
also provides MIL HDBK 217+M detailed stress. A traditional MIL
HDBK 217 Notice 2 with the +M option of using a supplemental
DfRSoft manufacturers' database as well as parts count for Telcordia (SRS 332 Issue 1). Where
appropriate on these prediction methods, the user may add
junction temperatures, and part stress levels in addition to
global parameter for base assembly temperatures.
DfRSoft MTBF INSTRUCTIONAL VIDEO
Temperature-Humidity (Peck), Temperature-Cycle (Coffin-Manson),
Vibration Acceleration Model. Vibration Fatigue X, Y, Z Axis
model, Modified Temperature-Cycle (Norris Lanzburg) acceleration
model, Arrhenius Least Squares Fit analysis for Activation
Energy determination, Arrhenius lifetime model, Electromigration
acceleration factor model, moisture diffusion time through
common plastic encapsulates at 85%RH , Dielectric Breakdown
accelerated E-Model, temperature acceleration popular doubles
every 10oC compared to Arrhenius model , Chi Square
additional sample size and/or test times needed for
qualification (Per Jedec JESD47-A ).
Test Planning: Chi-square life test planning for specific tests,
multiple tests, including High-Temperature-Operating-Life,
Temperature-Humidity-Bias, Temperature Cycle, and Vibration.
Exclusive from DfRSoft is an
optional sample size optimization search for multiple tests to demonstrate one
failure rate and optimization success details provided..
All with handy test planning print out summary. Multiple Chi-Square test
plan failure rate plotted over temperature test time. Confidence
provided for zero or non zero failures with failure rates and device hours analysis.
DfRSoft ACCELERATED TEST PLANNING INSTRUCTIONAL VIDEO
Test Plans for Assemblies, Hybrids or Semiconductors/Parts:
DfRSoft are full qualification test plans
developed from an interface that allows the user to enter the
qualification plan failure rate objective (with suggested
values), confidence level, number of allowed failures for the
qualification, and basic inputs for temperature cycle,
temperature-humidity-bias, and high temperature operating life.
Other qualification specific test optionally include, vibration,
ESD, solder joint studies for assemblies etc. The output is a
detailed flow chart with specified sample sizes and a
step-by-step process card that can be printed for conducting the
qualification. Numerous specification are recommended such as
from JEDEC, IEC…DfRSoft provides an optimization routine that
can optionally be used to find the minimum sample size in order
to satisfy an overall single test failure rate objective. An
activation code is required for this tool which is provided upon
DfRSoft QUAL PLAN PART 1&2 VIDEO
Parametric Reliability Analysis (2013 Version Only)
from DfRSoft - Parametric Reliability Analysis.
Assess device degradation failure rates over time without having
to test to failure and with more accuracy saving hours of test
time, at lower stress and with smaller sample sizes. Here is
There are three ways to assess the failure rate of a
device that drifts out of specification. As an example we will
do Power loss for a device.
Each way requires a Parameter Limit, such as Power Limit. Let
say 20% Power loss.
Method 1: Consider a power limit of 20%. Devices are on life
test and when they reach 20% Power Loss, this is treated as the
time to failure. In this method a catastrophic analysis is used.
Use for example the Rel plts page to do a Weibull assessment.
Put the times to failure for each device and perform the
analysis similar to catastrophic data analysis. In some cases
this may be the best method when an aging law is not known.
Method 2: Initial and Final Parametric Measurement Method:
In this method we require less test samples since we can
characterize the devices distribution with say 20 or 30 samples.
Typically device may be on life test at an elevated temperature
and we simply take two measurements at room temperature - before
and after the test. We have a population of samples and we find
its mean and sigma. At this point we can use the parametric
method where we can often prove a more accurate failure rate at
a specific confidence level than say a catastrophic analysis,
even when no failures occur. In addition we can get a point
estimate (i.e., no confidence bound data estimate) which cannot
be done when 0 failures occurs in the catastrophic analysis
method. To do this follow the hyperlink below for Initial and
Final drift measurement analysis.
Method 3: In this method, if a general aging model is known i.e.
how the drift for power loss occurs over time, then Parametric
reliability analysis makes the most sense and has tremendous
advantages over Method 1 & 2.
For example, the three aging laws in DfRSoft are:
Parameter Shift=A (Time)^B ,
Parameter Shift = A Log(1+B Time)
or Parameter Shift = User defined.
DfRSoft allows time to be accelerated with an
acceleration factor. An Arrhenius calculator is available to
determine this factor if temperature is the acceleration stress.
METHOD 3 ADVANTAGES:
If the Aging Law is known then there are three major advantages
over Method 1:
1. We require less test samples since we can characterize the
devices distribution with say 20 or 30 samples.
2. We do not have to test to failure only over a sufficient time
to fit the data to the aging law. With knowledge of the ageing
law and its distribution, the reliability can quickly be
predicted at any temperature.
3. We can test at a lower stress like a lower temperature since
we do not have to test to failure. Often the closer the
temperature to the use conditions for example, the more accurate
will be the prediction to the extrapolated temperature of
DfRSoft PARAMETRIC RELIABILITY INSTRUCTIONAL VIDEO
from DfRSoft - Chi-Square Multi-Test Reliability Growth as well
as the traditional Crow/AMSAA-Duane Reliability Growth (MIL STD
189) with and without test acceleration factors. Assessing your
reliability growth from one test to the next can be difficult
especially if you have few failures. DfRSoft now provides a
simple breakthrough Chi-Square accelerated reliability growth
tool for any one or more tests (RAMS
Publication in 2013). Results are in simple terms of
MTBF, AFR or PPM growth over test time. For example - take your
results from different tests such as thermal shock, humidity,
life test, or even drop tests, and now analyze your reliability
growth amongst these test in a simple straight forward way and
assess your product’s MTBF including Chi-square confidence and fix effectiveness.
As well as this new tool, DfRSoft provides the
traditional growth methods for analysis with
Crow/Amsaa & Duane
models for reliability growth assessment. Here as well we
provide very up-to-date reliability growth published
DfRSoft RELIABILITY GROWTH VIDEO
Handy look up table of the most common failure modes for PCBAs
and components, their failure mechanisms and suggested design
controls. Include your own database to the look up table as
well. Very friendly cut and paste common DFMEA Excel format
spreadsheet. Sorting capability with handy table pull downs.
Corrective Action Review (CAR):
DfRSoft provides a handy report form for CAR assessment that
includes a Fishbone diagram assessment
Environmental Profiling -
Enter the stress and time for each environmental type such as
Temperature, Temperature Cycle, Vibration and/or
Temperature-Humidity. For example, your system over its life may
be exposed to 25C for 10% of the time, 55C for 60% of the time
and 70C for 30% of the time. DfRSoft will calculate the
equivalent time at any temperature and the reliability given
these inputs. This Module also includes a step-stress correction
for temperature stress.
SPC Charting with Variable Sample Capability:
Plot SPC charts of lots displaying X bar & R Charts with S Charts
as well. Unlike most commercially-available SPC software, this
spreadsheet accepts variable sample sizes, and sets appropriate
Lot Sampling Plans (single and double
provides two types of automated lot sampling
plans : Hypergeometric
method (N, n, c) where N is the lot size, n is the sample from
the lot, and c is the number of sample(s) that are allowed
before the entire lot is rejected and the Binomial method (n, c)
"N not used". Two key values, AQL (Acceptable Quality Level),
and LTPD (Lot Tolerance Percent Defective) values. OC Binomial
and Hypergeometric lot curves plotting Probability of Acceptance
vs. Lot Percent Defective. Select N, n, c and AIQ obtain
AQL and LTPD, and AOQ with confidences.
This makes MIL-STD 105E or ANSI/ASQ Z1.4
Standards on Lot Sampling look easy and is much more flexible.
Sometimes we are not sure about a lot and we would like to do
more inspection or we may wish to take a risk and sample less
but decide that if we do this and exceed a certain criteria, we
might do a second sampling to decide whether or not to accept or
reject a lot. In addition to the single sampling, an example is
provided on using this tool for Double sampling which can
actually reduce the number of single samples taken.
Normal & Lognormal Probability Plotting:
Determine if your data is normally, lognormally distributed or another
distribution. Assessing normality or lognormality is
now easy and in one step. Extensive probability plots not only providing active probability
graph and histogram of entered data with cumulative and
probability density plots, but also providing a visual and
statistical measure of normality. Full statistics including
Mean, Median, Mode, Std. Dev., Std. Error, Skewness, Kurtosis, ,
probabilities and confidences. Probability plots of fixed
distribution with mean and std. dev. also available.
Cpk - Six Sigma Analysis:
Full, Upper, or Lower Cpk for specification limits, Six Sigma
DfRSoft also automatically
links Cpk to
resulting yield to help the user understand and interpret Cpk
values. , one- and two-sided with Cpk confidences.
A Six Sigma analysis tool is also provided with Cpk. Industrial
guidelines are given for both six sigma and Cpk analysis.
DfRSoft also provides target guidelines for Cpk and Six Sigma values.
Derating Guidelines, Availability, Sparing, Preventative
maintenance, Field Returns Analysis, Corrective Action Reporting
(CAR) with Fishbone Diagraming and ESD (see Reliability
Section for Details)
DfRSoft SPC & NORMALITY VIDEO
DfRSoft LOT SAMPLE PLAN VIDEO
Exponential Data Analysis over Time with Weibull & Mixed Modes
Data Assessment: MTBF analysis of shipped and returns per
month at various confidence levels is now easy to do with
number of units shipped per month; number returned per month,
add a delay (offset) for field instillation time, optional
capability to provide different number of hours in operation per
year with repairs versus replacement. Results is an Exponential
analysis providing the MTBF, failure rate, PPM analysis over
time at specified confidence level with and without the delay.
Then further analysis can be done, click on Weibull Analysis
Data Sort button. DfRSoft automatically sorts your data so that
you can easily import the data into DfRSoft's Reliability Plot
area where you can do a Weibull, Exponential and Mixed Modes
DfRSoft FIELD RETURNS INSTRUCTIONAL VIDEO
Availability analysis with plotting. Sparing - provides an
estimate of the number of spares needed based on MTBF, MTTR for
and includes a Binomial confidence of spare success for
mission time entered (up to 300 entries) with output also providing system
Availability, MTBF, Spare Cost, Total Spares, Average MTTR,
Average Item Cost. Also included is a preventative maintenance
Physics of Failure & DfRQ Library
Physics of Failure & DfRQ Library
Junction Temperature Analysis, CTE Mismatch
Assessment of Materials, BGA Solder Join Shear Strain
Assessment, Wire Bond Subject to Vibration & Shock Assessment,
Packaging Guidelines for Foam Thickness to Protect from Drop
Shock, Circuit Board Component Fatigue Life (Steinberg)
Assessment, Fatigue Life Estimation Using Miner's Rule, Gold Embrittlement, Purple Plague/Kirkendall
Voids Test, Black Pad ENIG Information, Silver Migration
Testing, Corrosion Analysis Help and more...
Basic suggested parts derating guidelines - Incorporating a mix of
industry standards including NASA, MIL STD 1547A, RAC, JPL with
programmed derating over temperature.
Thermal resistance, Heating, Time constant of material, basic
semiconductor Case-Junction temperature models, CTE mismatch and
solder joint shear stress and fatigue risks, Thermal Junction
Temperature of a hermetic power device, Transient Thermal
Response time, Pulse Mode Junction Temperature Rise,
experimental method of finding Tau Transient Temperature Rise
Time. IGBT Junction Temperature model with switching. Numerous
look up tables for many materials & allows providing thermal
Vibration and Shock Analysis :
Exclusive from DfRSoft is full Vibration and
Shock Analysis. One of the more advanced analysis tools you will find.
General conversion for
between acceleration, velocity, displacement, frequency.
PSD Random Vibration
Spectral Analysis (plots PSD vs Freq and finds Grms
content, Average and Max Velocity and Max Displacement likely
and possible. Also available –
Sine-on-Random plotting with Grms content, Average and Max
Displacement, Velocity likely and possible.
analysis for X, Y, Z axis with strategies to demonstrate
fatigue life from field data and minimal test times for each
(RPM versus radius, Gs), As well requirements for UD load for
shaker, Octave Sine analysis (time to run resonance search
test), Sine Vibration Q analysis.
Mechanical ED Shaker Shock
for multiple wave forms input Gs and Pulse duration obtain
stroke and max velocity.
Drop Shock height
estimations for - Half-Sine, Triangle, Sawtooth for given Gs and
Pulse Duration. Also available is packaging foam thickness
analysis for different Drop Heights and G capabilities of your
product. As well a strategy for Resonance Sine test conversion
to a Random test and Random to Sine.
CLICK TO SEE VIDEO ON DOING SHOCK AND VIBRATION ANALYSIS IN
Power conversions (dBm<>Watts), Voltage to Power conversions, dB,
Insertion loss, Power, & Voltage assessment, VSWR and Return
Loss calculator, Forward and Reflected power conversions,
American Wire Gauge calculator, Fusing current of Wire and
Circuit Traces analysis, Wire Bond current Density to Avoid
Electromigration/Fusing analysis, RC & Inductor Time Constant
Assessment, Capacitance and Inductor Impedance calculators,
Voltage Breakdown in Air at any Pressure (Pachen's Law). Voltage
Breakdown in a solid dielectric vs distance for different
material (with material table look up), Local Relative Humidity,
Temp at die surface, temperature rise in PCB circuit traces per
IPC-222, Life Expectancy of an Al Electrolytic capacitors,
Thermocouple Information, Resistivity and Temperature Coef. of
metal lookup table. Coming soon Smith Chart Calculator.
Corrosion analysis tools are not easy to find, DfRSoft provides a lot of
help in this area. Corrosion Conductivity-Resistivity calculator, Corrosion Rate of Metals
analysis, Oxidation Corrosion Rate, Corrosion rate of metals
when anode and cathode currents are known, Hydrogen Poisoning
assessment, Forms of Corrosion Table (such as Galvanic
corrosion, Uniform corrosion, Etc.). Galvanic Series in Sea
Water, Corrosion Prevention of Galvanic Corrosion Help, Tables
provided for material properties including full detailed
periodic table of the elements.
A highly practical
engineering set of conversion tools needed everyday for reliability, mechanical, and
electrical engineering. Failure Rate Conversion
(Exponential Distribution), Temperature Conversion, Length
Conversion, Energy & Work & Torque, Power dBm
<-> Watts, Voltage to Power in dBm with Load , dB &
Insertion Loss, Foward & Reflected Power - VSWR & Return
Loss, 3-Phase Voltage - Current - Power conversion, Mass
Conversions, Volume Conversions, Pressure & Gage Pressure
Conversions, Density & Mass with look up tables, Altitude versus
Pressure and Temperature,
Time-Hours-Minutes-Seconds-Weeks-Date-Time test schedule
planning, Energy and Wavelength Conversion, E & M Spectrum,
Universal Constants, Circular Conversion, Relative Humidity -
Dew Point -Temperature - Absolute Humidity-Vapor
Pressure-Specific Humidity-Saturated Vapor Pressure Conversion,
Local Versus Ambient Relative Humidity, Temp At Die Surface
Calculator, American Wire Gauge (AWG), Casimir Effect compared
to Electrical Attraction in MEMS
given material conductivity, MU, and thickness over specified frequency
range. Skin dept helps to calculate wire size & conductive path
sizes for RF to avoid getting transmission losses. We can also
assess skin depth for shielding against ESD events such as with
Examples are provided.
Basic ESD definitions, specifications, auditing guidelines, basic models
(HBM, CDM, MDM), sensitivity classifications, ESD protection
circuits for design - methods and concepts, humidity usage, Triboelectric
shielding effect etc. Key circuit protection devices and how they
are commonly used is illustrated. We also include proper ESD fixture design for
electrical testing so that you will not zap your product during
electrical test due to a not well understood CDM scenario. Don't get zapped - get protected.
for Reliability & Quality Cost Analysis: (2013 Version Only)
With this handy
calculator, one can quickly assess DfRQ tasks including
laboratory work like test loading labor hour, test set up
man-hours, chamber run time charges, engineering analysis time,
to estimate the total cost for any task quickly with summary
Spread Sheet of Engineering Information:
Detailed Periodic Table of the Elements, Series Expansions,
Reliability Acceleration Models...
Companies with Engineers Now Using DfRSoft:
Sandia National Labs, Hewlett-Packard, NASA, Motorola Solutions, Advanced Energy, Tyco
Electronics, MA/COM Technologies, Sierra Wireless, AMD, Northrop
Grumman, Mercury Computer, Baker Huges,
Nokia, Dell Computer, Raytheon, Vicor Power, Mercury Computer, Free Scale Semiconductor, Hittite Microwave,
3D Systems Corp., Measurement Specialties - Humirel, Science Applications
International, KCI Technologies, Vicor Power, Toyon Research Corp., Arcadis Design Eng., St. Jude Medical,
Enecsys Micro Inverters, Leben
Technologies, Synthes Anspach, dB Control, Array Converter, Cistel
Technologies-Canada, NuTune, Life Size Communications, iDirect, DMK Light
Solutions, Sinorel Beijing, Selex
Galileo - UK, Kolorrol Energy, Abound Solar, Cobhan-Electronic Systems,
Autoliv Inc., Woodward Inc, Framo-Engineering, Integrated Biometrics,
Virtium, Sigvardsson Consulting - Sweden, Plasma-Therm LLC, Physio-Control Inc,
Schlumberger Rosharon Campus...
Daniel Landry, Quality Manager, LifeSize
Communications Inc., (The High Definition Video Communications Company):
"The amount of product provided for the cost of this tool is impressive!
My original use is for field returns and system reliability analysis."
Mathias Sigvardsson, ILS Engineer: "I use DfRSoft for spare parts and
system reliability calculations. DfRSoft is the easiest program to use
that I've ever tried. It is also very easy to export calculations in
e.g. a word document and adjust what you want to show. I wanted a custom
adaptation which DfRSoft arranged immediately. I can really recommend
Ira Cohen - Reliability Engineer, Advanced Energy:
"The software appears overwhelming, as in what an incredible wealth of
information provided in one location!"
Mark Raggo - Quality Engineer, Sierra Wireless: "I
am blown away by how comprehensive these accumulation of models and formulas
cool stuff! This really moved me forward with understanding how all this hooks
Robert Brown -
Reliability Engineer, Selex
Galileo, UK: "The Software is an extraordinary useful set of DfR tools
in one package and a comprehensive
Nikesh Dhar - Reliability Engineer, Abound Solar:" I have found DfRSoft to be my primary tool that I uses for reliability
engineering...it does so much more than just analyze data. It is an
everyday type of tool."
Wilson - Reliability Engineering, AMD: "I have been using this just about daily
now, I like the Excel layout as I find it intuitive to use with the
handy pop up instructions right there."
Ali Kafi - Reliability Engineer, Array Converter: "What a great
software. It has all the calculators that I need and more."
Peter Ersland - M/A-COM Technologies: Software is used
for Chi-squared Acceleration Qualification Test Planning and everyday general reliability tools.
Yolanda Ma - Sinorel, Beijing: Sinorel reliability conducted a full
evaluation of DfRSoft and is looking forward to DfRSoft sales in China
DfRQ Classes and Software is unmatched in the industry. We provide the only low priced high value powerful Design for Reliability,
Quality, and Engineering software.
Our classes and software are practical and
comprehensive for commercial use. An easy to use software with
built in video instructions and pop-up help in friendly Excel format. It
is mobile software that you can use without a company's mainframe anywhere and anytime.
Our classes provide more technical knowledge and cover more material
than any other courses. We strive to help industry design in
reliability & quality. DfRSoft also provides reasonably priced consulting. Current classes
include, Design for Reliability & Quality (a fast paced course that jump starts
ones knowledge with DfRQ Software use), Understanding Shock & Vibration,
and Advanced ESD Auditing and Design. Our DfRQ class can be tailored to a
companies needs and its length varies between 2 or 3 days. Software is a
major learning tool as exercises can be done fast and more material can
be covered in a shorter time.
Dr. Alec Feinberg