15-JMP Pro 17 Process CapabilIty

TT-TE-TTM 533_1 TT-TE-TTM 533 Lean Six Sigma PROCESS CAPABILITY

TT-TE-TTM 533_2 TT-TE-TTM 533 Lean Six Sigma Objectives Discuss process capability terms Illustrate assessing process capability Understand the different capability indices Calculate process capability using JMP 17 Discuss using run charts and Pareto charts to establish a process baseline Review the Measure Tollgate

TT-TE-TTM 533_4 TT-TE-TTM 533 Lean Six Sigma Process Capability Terminology Specification Limits Boundaries, usually set by management, engineering or customers, within which a process must operate Voice of the customer Is the service or product meeting the customer’ s expectations? Process Capability Compares the output of an in-control process to specification limits using capability indices Answers the question of how well a process meets a customer’ s expectations

TT-TE-TTM 533_5 TT-TE-TTM 533 Lean Six Sigma Why Assess Process Capability? Allows us to quantify the nature of the problem we will attack as one of the following: ▪ Are the specifications correct for the parameter (Y) of interest (process or performance output variable)? ▪ Is the location of the central tendency of the parameter (Y) centered within the appropriate specifications? ▪ Is the process variation in the parameter greater than allowed by the specifications? ▪ Is the measurement system affecting our ability to assess true process capability? Allows the organization to predict defect levels.

TT-TE-TTM 533_7 TT-TE-TTM 533 Lean Six Sigma A Practical Illustration 115 110 120 125 105 Customer surveys and industry benchmarking indicate that customers will be satisfied if the temperature is between 110 and 120 degrees F. Minimum Specification Maximum Specification

TT-TE-TTM 533_8 TT-TE-TTM 533 Lean Six Sigma A Practical Illustration 115 110 120 125 105

TT-TE-TTM 533_10 TT-TE-TTM 533 Lean Six Sigma Capability Indices Capability indices can be divided into two categories: within (short-term) and overall (long-term). Within or Short-term capability studies are based on measurements collected from one operating run. Overall or Long-term capability studies consist of measurements which are collected over a longer period of time. It is assumed that data collected over a long period of time includes both common cause and special cause variation.

TT-TE-TTM 533_11 TT-TE-TTM 533 Lean Six Sigma Estimation of Capability Indices s * 6 ) LSL - SL U ( C term - short ) best ( p = C 3 Z (best) p ) best ( T S = s * 3 ) LSL - x , x - SL U ( Min Cpk term - short = Short-Term Capability Indices Long-Term Capability Indices s * 6 ) LSL - SL U ( P term - long p = P 3 Z p ) best ( T L = s * 3 ) LSL - x , x - SL U ( Min Ppk term - long =

TT-TE-TTM 533_13 TT-TE-TTM 533 Lean Six Sigma A Practical Illustration 115 110 120 125 105 How capable is the coffee shop?

TT-TE-TTM 533_14 TT-TE-TTM 533 Lean Six Sigma Example – Coffee Capability.jmp 1. Open the file Coffee Capability.jmp . from Wolfware for today 2. Analyze → Distribution 3. Select Temperature → Y, Columns → OK . 4. Click the red triangle next to Temperature and select Process Capability . 5. Lower spec limit is 110 6. Upper spec limit is 120 7. Target is 115 8. Select OK .

TT-TE-TTM 533_16 TT-TE-TTM 533 Lean Six Sigma Process Sigma The Sigma level is a measure of how often defects are expected to occur in a process.

TT-TE-TTM 533_17 TT-TE-TTM 533 Lean Six Sigma Sigma and Capability Cp Parts Per Million Defects σ 1.00 66,813 3.0 1.33 6,210 4.0 1.50 1,350 4.5 1.67 233 5.0 1.83 32 5.5 2.00 3.4 6.0

TT-TE-TTM 533_19 TT-TE-TTM 533 Lean Six Sigma Example: Ischemia Time 1. Open Sigma Calculator.xls . 2. Under Sigma Level-Continuous Data, type 27.96 in the Mean field. 3. Type 8.094 in the Standard Deviation field. 4. Type 30 in the USL field. Is this process operating at an acceptable sigma level?

TT-TE-TTM 533_20 TT-TE-TTM 533 Lean Six Sigma Example: CRO Patient Recruiting Background : A CRO has started to experience long delays in completing the projects they have been awarded in the last 12 months. The executive team identified several areas of the process that might be leading to the long delays. Several Six Sigma teams were formed to tackle this project. One team is addressing the amount of time spent recruiting patients for a study. Problem Statement : The average number of weeks needed to recruit patients for new studies has increased from 6 weeks to 10 weeks in the last year, resulting in significant delays in starting new trials.