P-CHART Template FOR CONSTANT SAMPLE SIZE (v. B3.0
THE FORGING PROCESS FOR THE MANUFACTURING OF CONNECTING ROD OF IC ENGINE
STEP 1 Enter the sample size and the number of nonconforming counted.
Sample size n= 550 Sample number m= 12
Data set
Sample number 1 2 3 4 5 6 7 8
D 1 2 1 2 1 7 2 1
STEP 2 Compute fractions, the central line and the limits
Sample number 1 2 3 4 5 6 7 8
D 1 2 1 2 1 7 2 1
p 0.003 0.002 0.003 0.004 0.002 0.013 0.004 0.002
pbar 0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.004
UCL 0.012 0.012 0.012 0.012 0.012 0.012 0.012 0.012
LCL 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
STEP 3 Plot the p-chart
p-chart
0.014
0.012
0.010
0.008
p
0.006
0.004
0.002
0.000
0 5 10 15
Sample number
Analysis
From the p-chart it is seen that the process is out of control. Sample number 6 is crossing the u
Steps have to be taken to remove this non-conformity.
LE SIZE (v. B3.0)
ROD OF IC ENGINE
orming counted.
9 10 11 12
1 3 1 2
9 10 11 12
1 3 1 2
0.003 0.005 0.001 0.003 0.045
0.004 0.004 0.004 0.004
0.012 0.012 0.012 0.012
0.000 0.000 0.000 0.000
p
pbar
UCL
LCL
15
umber 6 is crossing the upper limit.