Quality Calculator
Applications

MTBF SOFTWARE  PROGRAM

The really good news about this calculator?  It is at a very low downloadable price.  And it comes with 4 other calculators.  More on that below.

Some definitions:

PPM – (dpm) is defects per million "opportunities" for defects.  What is an opportunity for a defect?  That needs to be decided by each business.  One software group in a fortune 500 company decided that each line of code had a chance for a defect.  A number of manufacturers of printed circuit boards decided that the opportunities for defects was a total of the number of parts on that printed circuit board plus the total number of soldering connections on the printed circuit board. 

SIGMA - variation - as per the Quality definition of Six Sigma Variation.  This calculator is consistent with usage from a Fortune 500 Company  for the relationship between 6 sigma and defects per million opportunities. 

% AVAILABILITY - the percentage of "up time" (usability time) of a system / product.  The converse of this the "outage" time shown below it in time per year

 % / YEAR - Failures per year expressed in terms of a % of all products shipped / in use at that time - this is for the first year of service.  % / Month - is products for their first year of service, but averaged into one month failure percentages - % / Month will be 1/12 of % / Year. 

OUTAGE – Time the system is unavailable over a years total time 

Occur./yr – This is a variation on the above “OUTAGE” .  Outage is the total time the system is unavailable during a year.  One can also look at how many occurrences of outages per year such as this item “occur./yr” and then multiply by the average outage time for each outage occurrence to get total “OUTAGE” on a yearly basis. 

Avg. min – This is the average minutes for each outage “occurrence”.  Then this value times the number of “occur./yr” (occurrences per year) will give total OUTAGE time per year. 

MTBF - Mean Time between failures, expressed in total hours and total years 

FPM HOURS - Failure per million hours - as sometimes used by US Mil Standard 217 

FITs - Failures per billion hours - as sometimes used by Bellcore 

PPM / LIFETIME - failures per million products shipped during its lifetime.  Note that you will need to adjust the "lifetime reliability multiplier" for this to be able to be calculated.  That multiplier should be set to compare the average (for your product type) of first year product failures to lifetime product failures - based on your particular industry experience for your product. 

MTTR - is mean time to repair - or average product repair time, in hours.

Overall - Convert 2000 is a collection of Six Calculators

• Business Calculator:  A computer calculator with some excellent features.  It includes a simulated paper tape readout on screen that shows calculations as you go - and it can also print to a default printer.  It also includes 10 memory locations that are visible to help you remember which memory value is which.
• Metric to English Calculator: that includes conversions for:  weight, distance, volume, temperature, hexadecimal to ascii and decimal, and quality sigma to ppm
• Mortgage Loan Calculator: that allows you to calculate any of the four items of:  Principal (amount of loan) , interest rate, term of loan, or payment amount by entering the other  three.  An amortization schedule that also allows save and print is included.  Many options.
• Quality Calculator:  Many Handheld calculators will do statistics.  This one does not.  What it does do is include many items not found on hand held calculators including mtbf calculations, and the relationship between mtbf, mttr and system availability.  Also includes ppm to sigma calculations plus fahrenheit to celsius conversion.
• Chinese Calendar Calculator:  This calculator is a simplistic approximation of the Chinese tradition of naming years after animals and how it relates to our own Gregorian solar calendar years.  It is a simple approximation, and is mostly included for fun.
• Custom Calculator:  Allows 9 lines of programmable calculations.  It does not include all programmable functions, but includes many of the common ones such as addition, subtraction, multiplication, division, %, logs, natural logs, exponentiation, and more.  It does not allow parenthesis but does allow multi-line information transfer at least in a downward direction.  This can be set up for many common small business needs.  Examples included within the calculator.

Overall - Of course, with differences in definitions and rounding techniques, you will need to check settings and ensure suitability of these calculators for your own needs.  However, this software can be an exceptional help when you need it and it comes at a very low package price.  Switch from one calculator to another by simply clicking on the calculator you wish on the pull-down menu that it is on each main calculator screen.  An option file can remember your settings if you wish it to be saved.  Load and save of multiple options is also provided for.

Readme.txt and help included.

Links:  main convert program page             main page rpsoft 2000 software