Improved Applesauce Yields through Design of Experiments (DOE) Karl Hofman Director Rapid Continuous Improvement Dr Pepper Snapple Group

Transcription

1 Improved Applesauce Yields through Design of Experiments (DOE) Karl Hofman Director Rapid Continuous Improvement Dr Pepper Snapple Group

2 3 Takeaways 2

3 DPS is the Market Leader in many Categories Flavored CSDs Juice & Juice Drinks Premium Tea Mixers Gourmet CSDs 3

4 Rapid Continuous Improvement (RCI) A Culture Change Journey We are creating a culture of breakthrough change by: Setting breakthrough goals (GOAL deployment) Measuring progress and addressing root cause (CAP) Developing Lean leaders (tracks) 4

5 RCI Results 5,300 participants Kaizens 100 locations Balanced Approach to RCI: Safety 37% reduction in recordables Quality Consumer complaints down 25% Delivery Fill Rate 99.9% Productivity Reduced warehouse footprint by 2.5MM ft 2 (25%) Growth +50 bps in WD SSMP share Sustaining our World class status in Asset Utilization 58% lower than peers 5 5

6 Improving Applesauce Yield Using DOE and Minitab to Drive Improvement

7 Williamson, NY Home of Motts Applesauce Multiserve Applesauce (MSAS) Line Singleserve Applesauce (SSAS) Lines (3) Pouch Lines (2) 7

8 Applesauce Process Flow Overview KPIV's (X's) Applesauce Process Flow Start KPOV's (Y's) Ratio Local Rate (throughput) Speed of Auger Apple Hoppers Ratio of Bertocchi / Chopped Fruit Rotor Speed Auger Speed Rotopulse Speed Local Rate (throughput) Bertocchi Bertocchi apple stream Apple waste Speed Screen Size Local Rate (throughput) Apple Size Chopper Chopped Apples Speed Condition of Stator PC Pump Bertocchi/ & Chopped Apples Temperature Local Rate (throughput) Steam Pick 1 Heated Sauce Temperature Local Rate (throughput) Steam Pick 2 Heated Sauce Pressure Back Pressure Valve Cooked Sauce Cook Time Cook Tank Cooked Sauce Clearance of Screens Clearance of Paddles Position of Paddles Screensize Finisher Cooked Sauce DOE #2 Cooked Sauce heading to Pot Finisher Waste Stream Cooked Sauce Waste DOE #1 End Cooked Sauce to the Lines 8

9 Bertocchi Extractor Description The apple extraction processes for all applesauce lines in Williamson incorporate the use of a specific brand of extractor known as a Bertocchi extractor. Pictures of the Bertocchi used for the MSAS line and SSAS lines are shown below with key components identified: Rotor Screen Bertocchi Unit (opened with rotor and screen removed) Bertocchi Rotor and Screen (removed and separated) 9

10 Yield Loss/Waste Measurement A manual yield loss measurement process was developed enabling the team to directly measure the waste at each Bertocchi unit (MSAS and SSAS): 1. Bertocchi waste chute modification allows capture of waste stream 2. Timed waste collection 3. Weight measured and yield loss calculated based on output rate Manual waste measurement process enables analysis of Bertocchi parameters to optimize performance and reduce losses. Same method is applied to the finisher process. Question? Is this an acceptable measurement system? Need to perform an MSA. 10

11 Yield Loss/Waste Measurement Initial Gage R&R study conducted with 3 operators as a nested study and using 15 second measurement intervals Gage R&R Study - Nested ANOVA Gage R&R (Nested) for Result Source DF SS MS F P Operator Batch (Operator) Repeatability Total Gage R&R %Contribution Source VarComp (of VarComp) Total Gage R&R Repeatability Reproducibility Part-To-Part Total Variation Study Var %Study Var Source StdDev (SD) (6 SD) (%SV) Total Gage R&R Repeatability Reproducibility Part-To-Part Total Variation Number of Distinct Categories = 2

12 Yield Loss/Waste Measurement Repeat Gage R&R study conducted with 2 operators as a nested study and using 30 second measurement intervals Gage R&R (Nested) for Results Source DF SS MS F P Operator Sample (Operator) Repeatability Total Gage R&R %Contribution Source VarComp (of VarComp) Total Gage R&R Repeatability Reproducibility Part-To-Part Total Variation Study Var %Study Var Source StdDev (SD) (6 SD) (%SV) Total Gage R&R Repeatability Reproducibility Part-To-Part Total Variation Number of Distinct Categories = 7

13 MSAS Screen MSAS Screen Bertocchi Extraction Screen Life Current practice for Bertocchi process is to replace mechanical screen at 1 month (SSAS) and 2 month (MSAS) intervals. Comparison of older (end of life) screen and new (beginning of life) screen showed significant waste differences (simple comparative experiment on MSAS Bertocchi unit of old vs. new screen): New Screen MSAS Old Screen MSAS Boxplot of Yield Loss (Normalized) vs MSAS Screen Screen life impacts yield significantly. Comparison of old vs. new screen on the MSAS Bertocchi showed a ~60% improvement Yield Loss (Normalized) Mood Median Test: Yield Loss (Normalized) versus MSAS Screen Test for Equal Variances: Yield Loss (Normalized) vs MSAS Screen Multiple comparison intervals for the standard deviation, α = 0.05 Mood median test for Yield Loss (Normalized) Chi-Square = 6.56 DF = 1 P = New Screen MSAS Multiple Comparisons P-Value Levene s Test P-Value Individual 95.0% CIs MSAS Screen N N> Median Q3-Q New Screen MSAS ( * ) Old Screen MSAS (-----*--) Old Screen MSAS Overall median = * NOTE * Levels with < 6 observations have confidence < 95.0% A 95.0% CI for median(new Screen MSAS) - median(old Screen MSAS): ( , ) 13 If intervals do not overlap, the corresponding stdevs are significantly different.

14 Bertocchi Extraction DOE #1 Evaluation of equipment components showed screen life impact on yield what about process set-up and operating conditions? DOE (Design of Experiments) allows us to evaluate multiple process inputs, determine which inputs are critical and then reduce waste by optimizing those critical inputs in a minimal number of experimental runs. We identified 4 key inputs to evaluate (Bertocchi feed rate, Rotor Speed, Infeed Auger Speed and Rotopulse Speed). The optimal DOE design was determined to be a 4 factor, 1/2 fractional factorial design with 2 center points and 2 replicates for a total of 18 runs See Table Below: This DOE was performed in March 2015 on the MSAS Bertocchi unit with a new screen using the manual method of waste measurement 14

15 Bertocchi Extraction DOE #1 DOE results showed that Rotor Speed was the main factor affecting waste with Bertocchi Feed Rate having a minor impact on waste compared to Rotor Speed. All other factors had insignificant impact on waste. Rotor Speed (B) is the major factor affecting waste Bertocchi feed rate (A) is a minor factor affecting waste Other factors (C&D) and interactions do not impact waste Increasing Rotor Speed significantly reduces waste Decreasing Bertocchi Feed Rate slightly reduces waste 15

16 Evaluating the DOE #1 Model for Bertocchi Yield Evaluation of power of the experiment and residuals Power and Sample Size 2-Level Factorial Design α = 0.05 Assumed standard deviation = 0.34 Factors: 4 Base Design: 4, 8 Blocks: none Including a term for center points in model. Center Total Points Effect Reps Runs Power The power of the experiment is 74% and reasonable given the nature of our product (it s applesauce). The presence of heteroscedasticity in the residuals was identified but not concerning after replicating optimal settings post DOE Bottom line was that the DOE yielded a positive result that was demonstrated and sustained in process post DOE. 16

17 Putting DOE #1 Results into Practice Prior to the DOE, Bertocchi extractor screens were replaced based on time and multiple inputs on the Bertocchi extractor were adjusted to reduce losses with unpredictable and inconsistent results. Post DOE, it was established that screen wear and rotor speed for the Bertocchi extraction process were the only critical inputs affecting yield. Control charts were established on the Bertocchi waste stream to monitor yield at a set frequency and adjust rotor speed as needed to maintain process control until screen replacement was necessary. An I-MR Chart is used to track yield loss at the Bertocchi extraction process based on waste stream measurement. As yield loss increases, the Bertocchi rotor speed is adjusted until reaching it s practical process limit then the screen is changed. Note that as the process has continued, the UCL/LCL have tightened, showing a very consistent process yield. 17

18 DOE #2 Chopping and Finishing Process The second DOE was conducted on the chopping/finishing stream that is mixed with the Bertocchi stream to make our MSAS and SSAS products. The key factors considered were Bertocchi ratio (ratio of Bertocchi stream to chopped/finished stream) temperature (for chopped/finished stream) and tank level (for cooking tank for chopped/finished stream). Based on the factors and perceived significant interactions, a 2 level 3 factor full factorial design was selected with 2 center points and 2 replicates for a total of 18 runs for DOE #2. Run # StdOrder RunOrder CenterPt Blocks Ratio (Bertocchi) Cook Temp (Pick 1) Cook Tank Level This DOE was performed in July 2016 on the MSAS line using a new screen for the finisher process 18

19 DOE #2 Results DOE #2 showed that the only significant factor affecting overall process yield was the ratio of Bertocchi stream to chopped/finished stream. The higher the ratio, the lower the yield losses. Evaluation of the model showed no issues with residuals and a power of 74% which was acceptable (again, it s applesauce) Power and Sample Size 2-Level Factorial Design α = 0.05 Assumed standard deviation = Factors: 3 Base Design: 3, 8 Blocks: none Including a term for center points in model. Center Total Points Effect Reps Runs Power

20 Next Steps Increase the Bertocchi to Chopped/Finished Ratio to further optimize yield Shore up measurement system (perform further MSA studies to identify where we can reduce gage error) Implement similar process controls as Bertocchi (I-MR charting/spc) on yield losses at finishing process step Analyze incoming apple crop to understand key inputs and identify potential opportunities to further improve yields 20

21 3 Takeaways 21

22 Questions? 22