367 / 879
1i
i
i
M
)
1( x M
Résultat en
cours
Historique des
données
coefficient
coefficient
EWMA control chart
EWMA
N
°
patient
EWMA control chart
33
13. Control charts building: EWMA
Part 1
:
Introduction to
SPC
Part 2
:
Essential
concepts to
start with SPC
Part 4
Conclusion
Part 3
:
SPC in
practice
A
NALYZE
Individual value
/
Moving Range
Type of drifts to detect
Control charts
Small
and
slow
Ex.: wrong
adjustment of linac’s
parameters, errors
during
measurement…
Ex.: drift of the
detector’s dose
response
Diff. mes/calc. (%)
Patient number
EWMA
- Exponentially
Weighted Moving
Average -
Patient number
Diff. mes/calc. (%)
Large
and
Fast
(I,MR)
Individual value
o i
nge
Patients #
2
3%
4%
1%
2%
-1%
-2%
-3%
0%
03/10/17