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Already some years have passed since the release of the Comrel versions 6 & 7, which introduced the Symbolic Processor among other features. Whereas the basic theoretical concepts of componental time-invariant and time-variant reliability analysis remain unchanged new developments regarding optimisers, sampling options and not least GUI features asked for a major new release of our most used program.

We therefore like to announce Comrel V.8.


Highlights on new features of Comrel 8

  • The GUI was completely revised. The dialog box layout of earlier versions was abandoned and a much more powerful and modern tree-structure layout was realized. The new layout allows easier handling of large models and a much better navigation.



  • Triggered by the changes in the GUI also the Symbolic Processor was thoroughly updated. It allows to evaluate all functions ‘on the fly’ for an interactive check before actually running an analysis. As a consequence debug facilities are much more rich and lucid now.
  • The gradient free COBYLA search algorithm will find the b-point for the FORM method also for non-differentiable state functions.



  • The U->X transformation now allows also assignment of Moments of a distribution to constant Parameters or Reference Functions.
  • There is a new Monte Carlo sampling option in Comrel-TI: Design Point Sampling.

  • The NLPQL optimiser is available also in Comrel-TV.
  • The Multiple Runs feature allows combining a large number of individual runs for the same state function but with different sets of constant Parameters into one run.

  • The context sensitive help now is comprised in ‘smart’ Tool tips, which pop up whenever you touch a menu item. These Tool tips also allow a graphical view of the Stochastic Model in terms of plots of density and distribution functions.
  • The results are presented as a complete Job Protocol including all plots in Rich Text Format (RTF) ready to be imported into suitable word processors.



Prices: See Current Prices

You may download a Demo Version of Comrel 8 for trials of its new features and layout.

Comrel 8 is the basis of Costrel for reliability-based optimisation, which will be released soon.

Continue with Features of Comrel Continue with Example Symbolic vs. Professional

Features of Comrel

 

  • COMREL-TI for time-invariant and COMREL-TV for time-variant reliability analysis based on FORM/SORM
  • 4 alternative, efficient and robust algorithms to find the most likely failure point are built in including a gradient free algorithm for non-differentiable state functions.
  • Alternative computational options are Mean Value First Order (MVFO), Monte Carlo simulation, Adaptive Importance and Axis-Parallel importance Sampling schemes and Design Point Sampling.
  • 44 different univariate stochastic models
  • Arbitrary dependence structures in the stochastic model by Rosenblatt-, Hermite and Nataf-models
  • All kind of sensitivity information:
    global influence of basic variables on the reliability,
    sensitivities and elasticities of distribution parameters,
    mean and standard deviation,
    sensitivities and elasticities of constant parameters in the failure functions.
  • A parameter study can be performed for any quantity, be it a distribution parameter or a parameter in the failure functions. Plots of reliability, failure probability, reliability index, influence of basic variables, elasticity of parameter, of expected cost and of hazard rate are available.
  • The Multiple Runs feature allows combining a large number of individual runs for the same state function but with different sets of constant Parameters into one run.
  • The results are presented as a complete Job Protocol including all plots in Rich Text Format (RTF) ready to be imported into suitable word processors. Results can also be visualized and exported (Clipboard, Metafile, Bitmap) as pie-charts, bar-charts and plots. In addition, all results are provided on ASCII data files for other post-processing. If necessary, a detailed error trace back can be generated.
  • Time-variant reliability by the out crossing approach for stationary or non-stationary cases using regular or intermittent rectangular wave processes and differentiable Gaussian and non-gaussian translation processes (Hermite or Nataf processes).
  • Professional version requires the state functions (failure criteria) to be written in Fortran-90 and subsequent compiling and linking. Professional version may be necessary for complicated iterative state functions or when external programs have to be linked to the state functions.
  • Symbolic version requires state functions (failure criteria) to be specified in normal mathematical notation. The program automatically parses/interprets the state functions (no compile and link). Many predefined constants and functions. Built-in functions include all elementary, trigonometric, hyperbolic, logarithmic and special functions like the Gaussian distribution function and its inverse, Bessel and Gamma functions, numerical integration, differentiation and root finding, comparative operators and test functions.
  • Auxiliary user defined functions and reference functions also possible in the symbolic version (like subroutines in the professional version).
  • Help and Documentation for both the Symbolic and the Professional version:
    All operations are easy and direct by many icons and shortcuts. 'Smart' Tool Tips provide first useful information for all features. More and detailed help on both theoretical concepts and program handling can be activated - in part also as context sensitive help.
    Details of theory and a rich technical reference are documented in the manual. COMREL comes with a large set of carefully chosen examples.

Continue with Example Symbolic vs. Professional


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