RELIABILITY SOFTWARE

Basic Programs

Before I became a health physicist, my speciality was safety analysis, reliability analysis and probabilistic risk assessment of terrestrial and space nuclear power systems.  This wwk was predominantly in the 1980s, the heyday of PCs.  My first PC was the IBM PC, and I wrote many programs using DOS-based MS Basic.  With the later advent of Windows and the various versions of Visual Basic, these programs became unusable, as PCs no longer included Basic interpreters.  Many authors have since developed interpreters and compilers that enable old DOS-based versions of Basic to function.  Even with these tools it is frequently difficult to successfully run old Basic program because of diffences in supported syntax and input/output issues. 

One Basic interpreter that I have found to be user-friendly and that requires minimal re-coding is MMBasic written by Geoff Graham.  See box below for instructions for using MMBasic.

.BAS programs are described below..

Of course, if you already have a favorite way to run legacy Basic files, just download the .BAS files and have at it.

Spreadsheets

During the same time period, I also wrote many Lotus 123 spreadsheets for generic reliability problems.  These have been converted to MS Excel.

.XLSX spreadsheets are described below.



MMBasic

  • Website MMBasic.com
  • Download MSBasic.exe
  • MMBasic User Manual
  • GW-Basic User Manual

  • Implementation
  • MSBasic.exe is a single executable file and does not need installation. Simply save it to a folder where your .BAS files reside, or save it under \Program Files\MMBasic\
  • MMBasic is a subset of GW-Basic
  • Assign .BAS file types to be opened with MMBasic.exe
  • Pin MMBasic.exe to taskbar

  • Run .BAS Programs
  • .BAS files can be opened and run in the DOS window by either of three methods
    • Double click on .BAS file
    • Drag and drop the .BAS file onto the MMBasic.exe icon
    • Click on the MMBasic.exe icon, then type RUN "XXXX.BAS" in the DOS window

  • Input/Output
  • MMBasic input and output occurs in the DOS window.  If a printed copy or a PDF of the input/output is needed, that can be accomplished using Notepad
    • Right click on the DOS window top title bar
    • Click Edit
    • Click Select All.  The entire contents of the DOS window will be highlighted
    • Right click on the DOS window top title bar
    • Click Edit
    • Click Copy
    • Open Notepad
    • Open new file
    • Paste into Notepad
    • Print or generate PDF from Notepad

  • Syntax Limitations
  • MMBasic has a few syntax limitations
    • Does not support LPRINT
    • Does not support PRINT USING, therefore number strings cannot be formatted and numbers print as is

Code Writer

  • A useful tool to edit programs in any language incuding Basic is Code Writer
  • It can be downloaded and installed from the Microsoft Store
  • Assign .BAS file types to be opened with Notepad
  • Open .BAS file in Notpad
  • Highlight .BAS file in Notepad
  • Right click window > Copy
  • Open Notepad
  • Open new file
  • Paste into Notepad
  • Print or generate PDF from Notepad

Notepad

  • MMBasic input and output occurs in the DOS window.  If a printed copy or a PDF of the source code or input/output is needed, that can be accomplished using Notepad.  See instructions above.
  • Notepad is usually pre-installed in PCs.  If not, it can be downloaded at Notepad++

BASIC PROGRAMS

BERNOULI.BAS - Reliability Demonstration using Bernoulli Trials

  • Calculates the required number of trials for a given number of failures, or the number of failures for a given number of trials.  Input the desired reliability to be demonstrated at a specific confidence level and producer's risk.
    • Consumer's risk  --  True reliability < Required reliability
    • Producer's risk    --  True reliability > Required reliability

  • Download BERNOULI.BAS
  • The .BAS file is a text file and therefore will open in the browser window.  Right click > Save As > Delete .txt extension > Select folder > Save

  • Source code PDF

  • Sample input/output 1
  • Sample input/output 2
  • Sample input/output 3
  • Sample input/output 4

  • Bernoulli trial equations

BINOMIAL.BAS - Binomial Redundant Reliability

  • Uses the binomial expansion to compute the reliability of parallel operating redundant units when a minimum number are needed for system success and additional standby operating units are available as backup

  • Download BINOMIAL.BAS
  • The .BAS file is a text file and therefore will open in the browser window.  Right click > Save As > Delete .txt extension > Select folder > Save

  • Source code PDF

  • Sample input/output 1

  • Binomial expansion equations

BINWEIB.BAS - Binomial Reliability with Exponential or Weibull Failure Distributions

CHSQMTBF.BAS - MTBF Demonstration by Test Program

COMPDATA.BAS - Component Reliability Data

LOGBIN.BAS - Logarithmic Binomial Redundant Reliability

  • Uses the logarithmic binomial expansion to compute the reliability of parallel operating redundant units when a minimum number are needed for system success and additional standby operating units are available as backup

  • Download LOGBIN.BAS
  • The .BAS file is a text file and therefore will open in the browser window.  Right click > Save As > Delete .txt extension > Select folder > Save

  • Source code PDF

  • Sample input/output 1

  • Binomial expansion equations

MARKOV2.BAS - Markov Solution of Multi-State System Probabilities

POISSONO.BAS - Poisson Redundant Reliability of M + N Operating Units

  • Uses the poisson distribution for evaluating redundant operating systems. Applicable to parallel units such as heat pipes where M required and N spare (excess) units are all operating in parallel.

  • Download POISSONO.BAS
  • The .BAS file is a text file and therefore will open in the browser window.  Right click > Save As > Delete .txt extension > Select folder > Save

  • Source code PDF

  • Sample input/output 1

  • Poisson expansion equations

POISSONS.BAS - Poisson Redundant Reliability of M Operating plus N Standby Units

RMN.BAS - Reliability Analysis of Redundant Systems

  • Calculates reliability of redundant systems based on the general equation developed by Robert S. Pringle and Philip M. Gresho in "A Comprehensive Reliabilty Analysis of Redundant Systems", Journal of Spacecraft and Rockets, Vol. 4, No. 5, May 1967, pp 631-638.  RMN.BAS was originally written by Dwight Burgess and revised by Phil Rutherford.

  • Poisson-binomial models are used for evaluating reliability logic options include parallel operation redundancy or operating and standby redundancy with or without startup for operating units and with or without switching for employed standby units.

  • Download RMN.BAS
  • The .BAS file is a text file and therefore will open in the browser window.  Right click > Save As > Delete .txt extension > Select folder > Save

  • Source code PDF

  • Sample input/output 1

  • Pringle/Gresho paper

SCOREGEN.BAS - Statistically Correlated Component Failure

  • Models common cause failures in parallel replicate or diverse redundant systems using varying degrees of statistical correlation.  

  • Download SCOREGEN.BAS
  • The .BAS file is a text file and therefore will open in the browser window.  Right click > Save As > Delete .txt extension > Select folder > Save

  • Source code PDF

  • Sample input/output 1

  • Binomial expansion equations
  • Statistical correlation model and parameters

TTFTEST.BAS - Rank-Ordered Test-to-Failure Data

MS EXCEL SPREADSHEETS

ACCLIFE.XLSX - Accelerated Life Testing

GROWTH.XLSX - Reliability Growth

MOMENTS.XLSX - Method of Moments Combining of Normal and Logarithmic Distributions

  • Download MOMENTS.XLSX   MS Excel spreadsheet for adding and multiplying normal and logarithmic distributions.  Input normally distributed data with either mean and 95th percentiles or mean and variance.  Input logarithmicaly distributed data with either median and error factor or mean and variance.

SERPAR.XLSX - Serial and Parallel Reliability

  • Download SERPAR.XLSX   MS Excel spreadsheet to compute the reliability of series or parallel components.  Evaluation of OR gate and AND gate reliability block diagrams (RBD) or failure state diagrams (FSD).

  • Series / parallel reliability equations

SWITCH.XLSX - Reliabilty of Series and Parallel Switching Circuits

  • Download SWITCH.XLSX   MS Excel spreadsheet to compute reliability of series, parallel, series-parallel and parallel-series switching networks for open and closed failure modes.

TESTIME.XLSX - Test Time Required to Demonstrate MTBF

WEIBULL.XLSX - Weibull and Exponential Failure Rate Models