Six sigma concept

Application of Six Sigma in Dairy Industry

1. Six Sigma Concept: Applications and Advantages in Dairy Industry Submitted By: Nandita Das Dairy Chemistry ( Ph.D ) 1

2. CONTENTS 2

3. Introduction What is six sigma? It is a systematic and organized technique to improve the strategic process, new product development, service that focus on scientific and statistical methods to make considerable reductions in customer determined defect rates. This increase in performance and decrease in process variation . It leads to defect reduction and improvement in profits, employee morale and quality of product. (Linderman et al., 2003) ( Anbari , 2002; Schroeder et al., 2008) Six Sigma is a top-down solution to help organizations 3

4. Objectives of 6 σ : Improve customer satisfaction (Internal and External) Improve the quality of product and service Reduce the process cycle time Overall cost saving up to 30% Development of staff skill Where it is used: Manufacturing and service industries Sales and Marketing Accounting and Financing Product designing Supply chain management (Zu et al., 2008; Zahraee , 2016) (Sharma et al., 2013)

5. History Father of statistical quality Father of 6 σ ( Anbarai , 2002; Schroeder et al., 2008) 5

6. Approaches Of Six Sigma DMAIC APPROACH This is organizational based DMADV APPROACH This is based on customer needs and satisfactions (De Mast and Lokkerbol , 2012; Wright and Basu , 2008) 6

7. Define: to clarify the problem and analyze the benefits. Measure: to assess the current situation and translate the problem in to a measurable parameter (CTQ). Analyze: to determine the effect of factors and causes that affect the CTQ’s behavior. Improve: to improve the CTQs performance by designing and implementing the adjustments to the process. Control: to control the system and adjustment of the process management for sustainable improvements. Define design goals that are consistent with customer demands and the enterprise strategy. Measure and identify CTQs (characteristics that are C ritical T o Q uality), product capabilities, production process capability, and risks. Analyze to develop and design alternatives, create a high-level design and evaluate design capability to select the best design. Design details, optimize the design, and plan for design verification. This phase may require simulations. Verify the design, set up pilot runs, implement the production process and hand it over to the process owners. DMAIC This approach is undertaken to improve existing business process DMADV This approach is undertaken when there is a need to create new design or pr oduct . DMADV is also known as DFSS, " D esign F or S ix S igma 7 (Srinivasan et al., 2014; Antony et al., 2012)

8. Levels Of Six Sigma Implementation ( Su and Chou, 2008) 8

9. 9 They have got the prestigious achievement of SIX SIGMA RATING because of their percentage of correctness which is just perfect up to 99.999995 i.e. six decimals or more than that. Not many of the topmost companies are even near to it. This is simply incredible! Error Rate 1 in 16 million transactions Best example ( Vashisht , 2018)

10. CASE STUDIES Application of Six-Sigma DMAIC methodology in plain yogurt production process Curbing variations in packaging process through Six Sigma way in a large-scale food-processing industry 10

11. Case Study 1 (Hakimi et al., 2017) Approach 11

12. 12 Define: SIPOC diagram To identify the process outputs and the customers of those outputs so that the voice of the customer can be obtained 1 Brainstorming was executed by the team members based on 5M criteria (man, machine, material, method and measurement) and environment to specify all possible factors affecting quality of yogurt production process Measure: Cause and effect diagram 2 (Hakimi et al., 2017)

13. 13 Possible process factors affecting pH values of yoghurt S. No. Process factors Classification as per 5M 1 Skim milk powder Material 2 Heat treatment Method 3 Inoculation temperature Measurement 4 Oxygen concentration Machine 5 Incubation temperature Measurement 6 Concentration of starter culture Material 7 Incubation time Man 8 Fat% Material 9 Milk composition Material Process factors settings S. No. Process factors Label Low level setting High level setting 1 Skim milk powder (g/100 g) A 0.5 4.5 2 Inoculation temperature (ºC) B 50 55 3 Incubation temperature (ºC) C 40 44 4 Incubation time (hour) D 4 12 5 Fat percentage (%) E 1.5 3.5 (Hakimi et al., 2017) Analyze: Used DOE to analyze most possible factors influencing the pH values of yogurt. 3

14. 14 2 (5-1) Design for the pH experiments First order regression model is developed by Minitab software Main effects plot for pH (Hakimi et al., 2017)

15. Improve: The result of the analysis showed that incubation time (D) and fat percentage (E) were significant factors; in contrast, skim milk powder (A), inoculation time (B) and incubation temperature (C) were not significant. Increasing or decreasing the level of significant factors has high impact on pH value; on the other hand, the same is not true for non-significant factors and analysis of them during optimization process is not essential. (Hakimi et al., 2017) Consequently, the pH values in the range of the specification limits, 4.4-4.6, were satisfactory and the pH values less than 4.4 or higher than 4.6 were not appropriate. The optimal settings for control variables were obtained, considering the acceptable specification limits for pH value, through usage of desirability function method. 4

16. 16 The results showed that incubation time and fat percentage were significant factors on pH values of yogurt, and the optimum settings for these factors were defined as 12 h for the incubation time and 1.5 per cent for the fat% . Furthermore, implementation of improved processes in yogurt production line resulted in achieving the acceptable pH values of yogurt within the range of 4.2 to 4.4 in accordance with customer’s preferences. In this case study, the Six Sigma approach provided the company with an example of the advantages of dealing with a problem systematically . This case can prompt managers of the company to apply Six Sigma method to address complicated problems in other processes, where causes particularly are not clear. Control To gain the aim, necessary modifications and revisions in the process procedures and control plans were performed to provide consistency and reduce process variation and mistakes. For example, the CTQ function, pH value and the level of control variables were attached to the audit checklist to conduct verifications within the audits. Statistical process control charts are used to monitor a process to determine the probable variations that happen over time. Reaction plans were organized to assist operators in taking actions in case any deviation or shifts from acceptable range of pH values and optimal controllable variables into control charts occurred. 5 (Hakimi et al., 2017)

17. Case Study 2 17 Purpose: Implementation of DMAIC on one of the chronic problems, variations in the weight of milk powder pouch. (Desai et al., 2014) 1 2

18. 18 3 Cause-effect diagram After multi-voting results (Desai et al., 2014)

19. 19 Improve: Based on the root causes and the answers emerged from the five-why techniques, the following improvement measures were worked out. Alignment between augar screw and tube assembly should be checked every time when product changeover occurs. Air conditioning system must be able to meet the condition requirement of air in the room. Calibration frequency of weighing machine should be at least twice per month. Design of feedback loop of control system such that system response time reduced to minimum possible Level Planning for changeover of product should be such that it takes minimum time to set the machine for new product and maximize the machine availability time. Maintenance should be planned during product changeover. Control: Periodic review of the different measures recommended in improve phase. Application statistical quality control charts, like X-bar and S-chart to check the consistency of the process maintaining targeted sigma level. Conclusion: The implementation of DMAIC methodology resulted in understanding the problems from all aspects, qualitatively as well as quantitatively , and laying out the improvements through effective analysis of the roots of the problem. The problem of variations in the weight of 1 kg milk powder pouch was addressed satisfactorily and the rejection rate was brought down to 50 %. The potential of improvement thus appears significant if the same improvement methodology can be applied to packaging process of other varieties. The cumulative savings can be of very large magnitude justifying the application of Six Sigma improvement methodology across the unit on different packaging process. 4 5 (Desai et al., 2014)

20. Advantages of Six sigma in Dairy Industry 20 ( Vashisht , 2018; Kovach and Chu, 2011; Zhen, 2011; Tylutki and Fox, 2002)

21. Other applications Of Six Sigma (Chen et al., 2011; Gijo et al., 2011; Leao et al., 2011; Chang et al., 2012; Antony et al., 2012; Nepal et al., 2013) 21

22. CONCLUSION Six Sigma implies three things: statistical measurement, management strategy, and quality culture . It gives multidirectional benefits in relatively shorter duration of time . The list of benefits of Six Sigma is endless including better understanding of changing customer requirements, improvement of quality and delivery, reduction of waste, reduction of cost, development of robust products and processes, enhancement of competitive position, and sustained competitive advantage through continuous improvement of all business systems in the organization. On the basis of these advantages and flexibility of six sigma, it can be implemented at each and every step in dairy industry starting from dairy farm till sale of the finished product. Six Sigma approach provided the company with an example of the advantages of dealing with a problem systematically . This case can prompt managers of the company to apply six sigma method to address complicated problems in other processes, where causes particularly are not clear. Six Sigma is not being explored extensively by the Indian dairy industries. 22