Process Capability Frequency Whether a process is capable

Process Capability Frequency Whether a process is capable of meeting specification refers to the variability of the product in relation to the specification limits. Specification Limits set at: High Capability Frequency Medium Capability Frequency Mean Low Capability This resource was downloaded from https: //rsc. li/32 MW 3 Gd Process. Capability | 1

Process Capability Indices Process Capability Index Cp Cp = specification range 6 × standard deviation < 1 = low , 1. 0 to 1. 60 = medium , >1 = high Process Performance Index Cpk = lower of A or B A = upper specification limit - long term mean 3 × standard deviation B = long-term mean - lower specification limit 3 × standard deviation This resource was downloaded from https: //rsc. li/32 MW 3 Gd Process. Capability | 2

Calculating the Process Capability A product has a viscosity specification of 165 +/-5 units. The data below show the viscosity has changed over the last 80 batches. Calculate the mean and standard deviation (use a calculator) and process capability (Cp) and (Cpk) values. Is the production process high , medium or low capability? What is the consequence of the Cpk value? Batch 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Viscosity 169 165 169 163 165 160 167 161 168 163 166 162 167 161 167 165 168 161 Batch 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Viscosity 167 163 167 160 166 165 170 162 169 163 169 162 170 169 164 170 163 168 162 Batch 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Viscosity 167 163 169 166 170 162 170 161 170 163 166 162 171 165 167 164 169 164 168 163 Batch 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 Viscosity 169 163 167 162 171 164 168 165 168 162 171 162 168 163 171 164 168 166 Process. Capability | 3