Plackett-Burman screening design — calculate the main effect of each factor and flag any
parameter that shifts the result beyond the acceptance threshold. Pre-filled with the
Ni assay NMC 811 example (7 factors, 8 runs).
Response Metric
Effect Tolerance (%)
|% shift| ≤ 2% to pass
Grand mean: 48.2163
8 runs · 7 factors
Factor Definitions
Factor
Nominal
High (+)
Low (−)
Design Matrix & Run Results
Click a cell to toggle (+) ↔ (−). Enter the measured response for each run.
Run
A
B
C
D
E
F
G
Result
1
2
3
4
5
6
7
8
Main Effects
Factor
Mean (+)
Mean (−)
Effect
% Shift
Pass
A — RF Power
48.0325
48.4000
-0.3675
-0.76%
✓
B — Nebulizer Flow
48.2175
48.2150
0.0025
+0.01%
✓
C — Spray Chamber T
48.2150
48.2175
-0.0025
-0.01%
✓
D — Digestion Temp
48.1825
48.2500
-0.0675
-0.14%
✓
E — Digestion Time
48.2150
48.2175
-0.0025
-0.01%
✓
F — Sample Weight
48.2000
48.2325
-0.0325
-0.07%
✓
G — Viewing Height
48.2175
48.2150
0.0025
+0.01%
✓
Tolerance: |% shift| ≤ 2% · Grand mean: 48.2163
Effect Magnitude
Internal Standard Recovery
IS Label
Min Recovery (%)
Max Recovery (%)
⁴⁵Sc recovery per run (%)
⁴⁵Sc RecoveryPASS ✓
Min observed
95.8%
Max observed
99.1%
Accept: 85%–115% · 8 runs
Conclusion
✓ Method is ROBUST
No critical factors detected
All 7 factors show |% shift| ≤ 2% and IS recovery is within 85%–115% across all 8 runs.
Largest contributor: A — RF Power (-0.76%) — consider tightening SOP tolerance for this parameter.