SPC统计过程控制表格(英文版)

Sample Size 2 3 4 5 6 7 8 9 10 15 20 A2 1.88 1.02 0.73 0.58 0.48 0.42 0.37 0.34 0.31 0.22 0.18 limits for X and R charts Lower Limit D3 0.00 0.00 0.00 0.00 0.00 0.08 0.14 0.18 0.22 0.35 0.41 Upper Limit D4 3.27 2.57 2.28 2.11 2.00 1.92 1.86 1.82 1.78 1.65 1.59 1 / 5

Example:

We have a filling operation for a 16-oz box of cereal. The following 20 samples have been identified to build means and range control charts.

Number 1 2 3 4 5 6 7 8 9 10 Mean 16.24 16.36 16.29 16.23 15.75 16.04 16.35 15.54 16.12 16.48 Range 1.38 2.33 1.50 2.07 2.75 1.37 2.45 2.64 2.67 1.49 Number 11 12 13 14 15 16 17 18 19 20 Mean 15.84 16.34 15.82 16.5 15.95 16.23 15.95 15.84 16.10 15.98 Range 2.95 2.57 2.72 2.13 1.65 3.58 1.68 1.73 2.80 1.89 X = 16.1 R = 2.22

Given the following Set of Data, Determine if the process is in control. Do this for the means chart and the range chart. Sample 1 2 3 4 5 6 Mean 16.2 15.9 16.3 16.4 15.8 15.9 Range 2.0 2.1 1.8 3.0 3.5 3.1 Sample 7 8 9 10 11 12 Mean 16.0 16.1 16.3 16.3 16.4 16.5 Range 2.9 1.8 1.5 1.0 1.0 0.9 pute the Upper and Lower Control Limits from original data; 1. Means:

UCL =

LCL =

2 / 5

2. Range:

UCL =

LCL =

3 / 5

Attribute Charts

Using the following information, construct a control chart that will describe 95.5 percent of the chance variation. Each sample contains 100 units.

Sample 1 2 3 4 5 6 7 8 9 10 Defects 14 10 12 13 9 11 10 12 13 10 Sample 11 12 13 14 15 16 17 18 19 20 Defects 8 12 9 10 11 10 8 12 10 16 Total Number of Defects = 220

PdefectsˆPobservationsP(1P)= n

UCL =

LCL =

4 / 5

Rolls of coiled wire are monitored using a C-chart. 18 rolls have been

examined and the number of defects per roll has been recorded. Is the process in control? Use 2 standard deviation control limits.

Sample 1 2 3 4 5 6 Total Defects: 45

defectsC

observations

UCL =

LCL =

Defects 3 2 4 5 1 2 Sample 7 8 9 10 11 12 Defects 4 1 2 1 3 4 Sample 13 14 15 16 17 18 Defects 2 4 2 1 3 1 5 / 5