361 / 879
Individual Value
control chart
Individual values
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% -0,71% 3,99%
Patient #
Beam #
Individual Values (%)
Patients #
28
Part 1
:
Introduction to
SPC
Part 2
:
Essential
concepts to
start with SPC
Part 4
Conclusion
Part 3
:
SPC in
practice
A
NALYZE
11. Control charts building: Individual value
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)
Indi i
l value
/
an
26
03/10/17