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Diffstat (limited to 'docs/cpta')
| -rw-r--r-- | docs/cpta/methodology/index.rst | 50 |
1 files changed, 25 insertions, 25 deletions
diff --git a/docs/cpta/methodology/index.rst b/docs/cpta/methodology/index.rst index 35c438d8b6..d89a6d7aed 100644 --- a/docs/cpta/methodology/index.rst +++ b/docs/cpta/methodology/index.rst @@ -94,16 +94,16 @@ over the rolling window of last <N> sets of historical measurement data: Outlier Detection ````````````````` -Outlier evaluation of test result of value :math:`X_n` follows the -definition from previous section: +Outlier evaluation of test result of value *X* follows the definition +from previous section: -+--------------------------------------------+----------------------+ -| Outlier Evaluation Formula | Evaluation Result | -+============================================+======================+ -| :math:`X_n < \left( Q1 - 1.5 IQR \right)` | Outlier | -+--------------------------------------------+----------------------+ -| :math:`X_n >= \left( Q1 - 1.5 IQR \right)` | Valid (For Trending) | -+--------------------------------------------+----------------------+ ++----------------------------+----------------------+ +| Outlier Evaluation Formula | Evaluation Result | ++============================+======================+ +| X < (Q1 - 1.5 * IQR) | Outlier | ++----------------------------+----------------------+ +| X >= (Q1 - 1.5 * IQR) | Valid (For Trending) | ++----------------------------+----------------------+ Anomaly Detection ````````````````` @@ -112,15 +112,15 @@ To verify compliance of test result of valid value <X> against defined trend metrics and detect anomalies, three simple evaluation formulas are used: -+---------------------------------------------------------------------------+-----------------------------+-------------------+ -| Anomaly Evaluation Formula | Compliance Confidence Level | Evaluation Result | -+===========================================================================+=============================+===================+ -| :math:`\left( TMM - 3 TMSD \right) <= X_n <= \left( TMM + 3 TMSD \right)` | 99.73% | Normal | -+---------------------------------------------------------------------------+-----------------------------+-------------------+ -| :math:`X_n < \left( TMM - 3 TMSD \right)` | Anomaly | Regression | -+---------------------------------------------------------------------------+-----------------------------+-------------------+ -| :math:`X_n > \left( TMM + 3 TMSD \right)` | Anomaly | Progression | -+---------------------------------------------------------------------------+-----------------------------+-------------------+ ++-------------------------------------------+-----------------------------+-------------------+ +| Anomaly Evaluation Formula | Compliance Confidence Level | Evaluation Result | ++===========================================+=============================+===================+ +| (TMM - 3 * TMSD) <= X <= (TMM + 3 * TMSD) | 99.73% | Normal | ++-------------------------------------------+-----------------------------+-------------------+ +| X < (TMM - 3 * TMSD) | Anomaly | Regression | ++-------------------------------------------+-----------------------------+-------------------+ +| X > (TMM + 3 * TMSD) | Anomaly | Progression | ++-------------------------------------------+-----------------------------+-------------------+ TMM is used for the central trend reference point instead of TMA as it is more robust to anomalies. @@ -135,13 +135,13 @@ ago, TMM[last - 1week] and to the maximum of trend values over last quarter except last week, max(TMM[(last - 3mths)..(last - 1week)]), respectively. This results in following trend compliance calculations: -+-------------------------+---------------------------------------------+--------------------------------+------------------------------------------------------------------------------------------------------------+ -| Trend Compliance Metric | Change Formula | Value | Reference | -+=========================+=============================================+================================+============================================================================================================+ -| Short-Term Change | :math:`\frac{Value - Reference}{Reference}` | :math:`TMM \left[ last \right] | :math:`TMM \left[ last - 1 week \right]` | -+-------------------------+---------------------------------------------+--------------------------------+------------------------------------------------------------------------------------------------------------+ -| Long-Term Change | :math:`\frac{Value - Reference}{Reference}` | :math:`TMM \left[ last \right] | :math:`max \left( TMM \left[ \left( last - 3 mths \right) .. \left( last - 1 week \right) \right] \right)` | -+-------------------------+---------------------------------------------+--------------------------------+------------------------------------------------------------------------------------------------------------+ ++-------------------------+---------------------------------+-----------+------------------------------------------+ +| Trend Compliance Metric | Trend Change Formula | Value | Reference | ++=========================+=================================+===========+==========================================+ +| Short-Term Change | (Value - Reference) / Reference | TMM[last] | TMM[last - 1week] | ++-------------------------+---------------------------------+-----------+------------------------------------------+ +| Long-Term Change | (Value - Reference) / Reference | TMM[last] | max(TMM[(last - 3mths)..(last - 1week)]) | ++-------------------------+---------------------------------+-----------+------------------------------------------+ Trend Presentation ------------------ |