Quality Management 2017

A NALYZE

13. Control charts building: EWMA

Type of drifts to detect

Control charts

Part 1 :

Introduction to SPC

Ex.: wrong adjustment of linac’s parameters, errors during measurement…

Large and Fast

l

/

Individual value / Moving Range o i nge

(I,MR)

Part 2 :

Patient number

Diff. mes/calc. (%)

Essential concepts to start with SPC

EWMA - Exponentially Weighted Moving Average -

Ex.: drift of the detector’s dose response

Small and slow

Part 3 :

Patient number Diff. mes/calc. (%)

SPC in practice

EWMA control chart

Patient #

Beam #

Part 4

Conclusion

03/10/17

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