Growth Planning Folio QCP

For reliability growth data analysis only.

After you have used the data sheet in the growth planning folio to create a reliability growth program test plan, you can use the Quick Calculation Pad (QCP) to calculate a variety of results that are expected if you implement the plan.

To open the QCP for growth planning folio calculations, choose Test and Planning > Analysis > Quick Calculation Pad or click the icon on the control panel.

To perform a calculation, click one of the buttons on the left side of the window and enter any required inputs in the Input area, then click Calculate. For more detailed information about all the options available in the QCP, see Quick Calculation Pad (QCP).

Continuous Growth Planning Folio

For the Crow Extended model, the options are:

  • Nominal MTBF and Nominal Failure Intensity calculations reflect the best case scenario. They assume that the average fix delay is zero.
  • Actual MTBF and Actual Failure Intensity take into account the average fix delay. If fixes are not incorporated instantaneously, the actual value will show slower growth compared to the nominal value.
  • Planned MTBF and Planned Failure Intensity return the expected MTBF or failure intensity at the beginning of each test phase. To perform this calculation, you must select the phase from a drop-down list. Note that, unlike the other calculations, you can calculate confidence bounds on the planned growth values, but only when you have at least 3 test phases specified on the folio's data sheet.
  • Discovery Rate is the rate at which new BD failure modes are being discovered at the specified time.
  • MTBF B Unseen is the mean time between failures due to B failure modes that have not yet appeared in testing but are estimated from the analysis. These are failure modes that would be fixed if they were discovered.
  • Cum. Num. B Modes is the cumulative number of B failure modes that are expected to have been seen during testing by the specified time (i.e., failure modes that will be fixed).

For the MIL-HDBK 189 model, the options are:

  • Idealized Growth MTBF and Idealized Growth Failure Intensity calculations reflect the best case scenario.
  • Average MTBF and Average Failure Intensity return the expected MTBF or failure intensity at the beginning of each test phase. To perform this calculation, you must select the phase from a drop-down list. These options are available only if the accumulated test time is known.

Discrete Growth Planning Folio

  • Nominal Reliability, Nominal MTrBF and Nominal Failure Intensity calculations reflect the best case scenario. They assume that the average fix delay is zero.
  • Actual Reliability, Actual MTrBF and Actual Failure Intensity take into account the average fix delay.
  • Planned Reliability, Planned MTrBF and Planned Failure Intensity return the expected value of the metric at the beginning of each test phase. To perform this calculation, you must select the phase from a drop-down list.
  • Discovery Rate is the rate at which new B failure modes are being discovered at the specified time.
  • MTBF B Unseen is the mean time between failures due to B failure modes that have not yet appeared in testing but are estimated from the analysis. These are failure modes that would be fixed if they were discovered.
  • Cum. Num. B Modes is the cumulative number of B failure modes that are expected to have been seen during testing by the specified time (i.e., failure modes that will be fixed).

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