.. _sphx_glr_api_gallery_reliability_growth:

Growth
------

How reliability improves while a design is tested and fixed.


.. raw:: html

  <div id='sg-tag-list' class='sphx-glr-tag-list'></div>


.. raw:: html

    <div class="sphx-glr-thumbnails">

.. thumbnail-parent-div-open

.. raw:: html

    <div class="sphx-glr-thumbcontainer" tooltip="James Duane, at General Electric&#x27;s Motor and Generator Department, plotted the failure records of five development programmes, from hydraulic devices to aircraft generators. On log-log paper the cumulative MTBF, total test time over total failures, rose along a straight line, each programme with a slope near 0.5. A straight line is a power law, \theta_c = K t^\alpha (~engineeringkit.reliability.reliability_growth_duane), so a few months of data predict how much more testing a reliability target needs. Because the failure count is N(t) = t^{1-\alpha}/K, the current failure rate is dN/dt, and the instantaneous MTBF is the cumulative one divided by 1 - \alpha.">

.. only:: html

  .. image:: /api/gallery/reliability/growth/images/thumb/sphx_glr_plot_01_duane_growth_thumb.png
    :alt:

  :doc:`/api/gallery/reliability/growth/plot_01_duane_growth`

.. raw:: html

      <div class="sphx-glr-thumbnail-title">Duane's reliability growth (1964)</div>
    </div>


.. thumbnail-parent-div-close

.. raw:: html

    </div>


.. toctree::
   :hidden:

   /api/gallery/reliability/growth/plot_01_duane_growth