364 / 879
1
2
3
4
5
1
1,00% -1,80% 1,68% -1,07% 3,20%
2
2,02% -1,27% -1,15% -0,55% 3,58%
3
0,20% 2,10% 2,83% -0,52% 5,49%
4
2,11% -2,06 % 0,64%
-
3,68%
5
4,61% 0,78% -0,39%
-
-
MEAN
1,99% -0,45% 0,72% -0,72% 3,99%
MOVING-RANGES
-
2,44% 1,17% 1,44% 4,70%
Patient #
Beam #
Moving-ranges. (%)
Patients #
Moving-range
control chart
12. Control charts building: Moving-Range
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. (%)
(I-
MR
)
o i
nge
29
03/10/17