Quality: Production line- Tea

1. Quality: Production line- Tea Infuse

2. Everything starts with a question Q: How often do you change the tea leaf? A: No idea, but it doesn’t matter so… Why don’t we try to answer the question ourselves? A improvement driven direction formed

3. Definite of the projects D • Target • Obtain infused tea with similar level of Tea Polyphenol • Balance between tea polyphenol and cost

4. Demonstrate SIPOC analysis and simulation D SIPOC: Production line Output Customer Supplier Input Process • Dilution session • Infuse for 10 minutes • Compress with high pressure for rotation • Heater session • Time of tea be infused • Volume of water (100L ) • Water temp. (90°C) • Amount of Tea leave • Type of tea… • Concentrated of Tea Polyphenol simulation Tea leave Water Infuse time Action • 2g of tea leave per unit, 6 units • 90 °CWater • 750ml • Shake with hands in metallic container • 4 minutes • Technician cannot provide the amount for tea leave for the production line Remark

5. Methodology-Testing solution D

6. Methodology-Testing solution Control solutions D Sample solutions • Control solutions • Sample solutions

7. Methodology Testing solution D • Operated by the same person at each role • Stir tea sample before used • Filter tea sample before used with filter paper • Cooled the sample tea to room temperature (about 26 °C) for 50 minutes。

8. Measurement • Process Capability and Variability • Variance caused by Location: intuitively, liquid are uniform after stirring. • Variance caused by the property change after being infused. • Assuming that there exists a function: for certain type of tea, where is standard normally distributed, F(.) is a discrete function and very likely to be non-increasing • Suppose that we will infuse the tea for time: M Given in advance

9. Measurement - Design of Experiment • Factors studied • Times of tea be infused • 1, 2, 3, … • Type of tea • Non quantifiable • The difference of the first factor’s impact on different type of tea • Response variable • concentration of Tea Polyphenols(茶多酚) X M Y

10. Measurement - Design of Experiment • Measurement System Variation Analysis • Variation due to Gage • A machine is used for measuring the concentration in the experiment. • Chemical reagent might change over time. • Variation due to Operators • Certain procedures are performed by the same operator through one block. M

11. Measurement - Design of Experiment • Other DOE Principles considerations • Randomization • No subjective bias since we are using the machine to test the ingredient. • Replication vs. Repetition • Standard procedures • Aiming at insight • Blocking • A fixed group of members for each different type of tea M

12. Improvement • PCA of the improved process • New function between X and Y: where is the error term of the new process. • Hypothesis: the improved process can provide better with same material cost. • Tips: • might be influenced by how many blocks we are using, we are only comparing the case that use the same average amount of tea. I

13. Results of Jasmine tea A Tea Polyphenols decrease with infuse #

14. Analysis – result A Different type of tea, different shape of curves Tea Polyphenols decrease with infuse # Decrease rate varies with kind of tea leave

15. When to change tea leave?Suggestion 1: Observation • Change tea leave based on observation A Pu-erh tea 1st 2nd 3rd 4th 5th 6th Infuse # • Label the 1st and 6th infuse tea • Add transparent glass layer to the container for observation Challenge • From previous data, darkness is proportional to the number of Tea Polyphenol

16. Concern: suggestion 1: Observation • Change tea leave based on observation Jasmine tea A Let’s see the number of Tea Polyphenol of Jasmine tea • Label the 1st and 6th infuse tea Challenge

17. Analysis – result A Tea Polyphenols cannot be determined by darkness (color) Common quality problem Why 3 types of tea? Misleading if just investigate the Tieh-Kuan-Yin Tea and Pu-erh tea Drawing a wrong solutions

18. Original Changing stragty Jasmine Tea Pu-erh Tea Tieh-Kuan-Yin Tea A Color difference Similar color Color difference Original method cannot provide uniform tea polyphenols, we need to change

19. Proposed idea Record Number inside Refer to Infuse # to that box Change: Throw in next infuse Change: Add in next infuse

20. Analysis – result A

21. Analysis - PCA • Process Capability Analysis A

22. Control • Measurement/ control system design • To maintain the performance in real manufacturing situation. • Performance monitoring and parameter modification on the arrival of new batch of tea. • Considering the influence of difference between batches Where is the factor of batches, which can regarded as constant for same batch, C

23. Equipment-a device that can solve the problem I

24. Equipment-a device that can solve the problem I

25. Equipment-inside view I

26. Conclusion • We should chance the tea leave every time • Apply 6 boxes designed • Solve costly problem • Maintain the relatively stable level of tea Polyphenol

27. Some discussions • The definition of our quality is the variance of Tea Polyphenols’ concentration only in our work. • Further study can be focused on how many blocks we should have in the device we designed so that the level of Tea Polyphenols can meet the standards, which is too time consuming for us considering the experiment we already made. • Our study is a very practical one, not so theoretical.