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Application of Six Sigma methodology in an Indian chemical company
Article in International Journal of Productivity and Performance Management · April 2020
DOI: 10.1108/IJPPM-03-2019-0128
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Application of Six Sigma methodology in an Indian
chemical company
Vishal Singh Patyal
NTPC School of Business (NSB), Noida, India
Sachin Modgil
International Management Institute–Kolkata, Kolkata, India, and
Maddulety Koilakuntla
S P Jain School of Global Management–Mumbai, Mumbai, India
Abstract
Purpose–The aim of this paper is to deploy Six Sigma (SS) methodology for addressing the customer complaints pertaining to Chemical-X in an Indian chemical company.
Design/methodology/approach–The study followed a structured Define, Measure, Analyze, Improve, Control (DMAIC) approach to address the customer complaints. The complaints have been classified into different categories along with a project charter in the define phase. In the measure phase, measurement system analysis (MSA) and supplier, input, process, output and control (SIPOC) have been applied. In the analyze and improve phase, why–why analysis, process capability study, how–how analysis, Gage repeatability and reproducibility and Taguchi design have been applied to optimize the manufacturing process parameters for Chemical-X. Lastly, in the control phase, validation of 20 batches has been piloted to validate the optimized parameters.
Findings–The findings of this study highlight the optimization and prioritization of the process parameters.
It shows that humidity has the least impact on the manufacturing of Chemical-X, whereas shift type has the maximum impact. The experimental output indicates that the 1st Shift, the holding time after grinding should be twenty-four hours, and the temperature after grinding should be 408C to reduce the customer complaints concerning lumps formation in Chemical-X.
Research limitations/implications–The study is performed for a single product (Chemical-X). It has focused only from the manufacturing process view and not from the transportation, suppliers and downstream supply chain view.
Originality/value–A systematic and data-driven approach of the SS methodology ensured that the customer complaints due to lumps formation reduced from 5% (approx.) to 1% (approx.) which resulted in the cost saving of INR 4 million (approx.) annually.
KeywordsSix Sigma, Quality, DMAIC, Customer complaints, Taguchi Paper typeResearch paper
1. Introduction
In today’s dynamic environment, customer preferences and requirements are changing at a faster rate. Past literature shows that customers’loyalty and their satisfaction are key factors for achieving sustained profitability of the companies (Athanassopoulos and Iliakopoulos, 2003;Bateh and Farah, 2017;Shamsuzzaman et al., 2018;Suchanek and Kralova, 2019).
Customer satisfaction measures“the extent to which a product successfully serves the purpose of customers”(Jahanshahiet al., 2011, p. 254). Organizations need to follow the zero-defect philosophy in order to create and retain customers (Psarommatis et al., 2019). There is tremendous pressure from customers and competitors to offer higher value in their products or services in terms of quality, cost and delivery (Antonyet al., 2018;Gijoet al., 2019). The
Six Sigma methodology and its applications
The authors express sincere thanks to Dr. Nicky Shaw, Editor for her insightful comments and suggestions. We are also thankful to the anonymous reviewers for their valuable review.
The current issue and full text archive of this journal is available on Emerald Insight at:
https://www.emerald.com/insight/1741-0401.htm
Received 10 April 2019 Revised 16 January 2020 9 February 2020 Accepted 15 February 2020
International Journal of Productivity and Performance Management
© Emerald Publishing Limited 1741-0401 DOI10.1108/IJPPM-03-2019-0128
customer complaint should be considered as voice of customer, what actually they want and why they have complained should be verified by reengineering product/service lot wise, that was supplied to customer (Dingemans, 1996;Cook and Macaulay, 1997). Moreover, customer complaint provides a chance to organization to take out useful information that can be applied to avoid future complaints (Bosch and Enrıquez, 2005).Stauss and Schoeler (2004) reported that customer complaint management should be done in a way that can guarantee customer satisfaction and retention (Knox and Van Oest, 2014;Anshariet al., 2018). The research illustrates that a satisfied customer may or may not tell others, but an unsatisfied customer will influence at least twice as many people as the satisfied ones would tell (Dingemans, 1996;Stauss and Schoeler, 2004;Fierroet al., 2014;Chicuet al., 2019).
Six Sigma (SS) is a breakthrough methodology that helps organizations to drastically improve their bottom line by designing and monitoring everyday business processes by eliminating waste, reducing cost of poor quality and improving the efficiency and effectiveness of their processes (Hoerl and Snee, 2012;Magnussonet al., 2003;Sodhiet al., 2020). SS is a statistical methodology that focuses on continuous improvement and aims at 3.4 Defect per Million Opportunities (DPMO) and ultimately led to customer satisfaction (Motwaniet al., 2004;Patyal and Koilakuntla, 2016;Chicuet al., 2019). The SS methodology has been applied across many business sectors to improve the processes which help in improving the quality of their products and services (Kwak and Anbari, 2006;Bateh and Farah, 2017). It relies on two improvement methodologies: one for pre-existing processes, Define, Measure, Analyze, Improve and Control (DMAIC) and the other for new ones Define, Measure, Analyze, Design and Verify (DMADV) (Patyal and Koilakuntla, 2015;Guptaet al., 2019). The DMAIC methodology is an appropriate approach to find out the reasons for customer complaints related to different products or processes (Antony, 2006;Limet al., 2019). The present study has considered a case of a chemical company in India which was facing the problem of increasing customer complaints. The SS DMAIC project was undertaken to reduce the potential customer complaints by analyzing the cause and effect relationship between the types of complaints and associated parameters. The similar types of defects were identified and their root causes are investigated. Further, recommendations for improvement are suggested and applied. The resulting customer complaint rate is compared to the historical one and validation trails were conducted to sustain the same.
The study has the following research questions (RQs) to address:
RQ1. What are the process parameters that affect the customer complaints?
RQ2. Is there any variation in the process due to the existing measurement system?
RQ3. What are the optimum factor levels that will help to reduce the customer complaints?
The remainder of the paper is laid out as follows: The second section highlights the literature review and third section displays the research methodology. Case study background is highlighted in section four, and DMAIC approach is delineated in section five.
Recommendations and implications are described in section six. Section seven highlights the conclusion followed by limitations and scope for future research.
2. Literature review
Quality plays an important role in satisfying customer needs and expectations which influence customers’decision to buy a particular product or service (Zuet al., 2008). It also focuses on customer centric measures like availability, reliability, delivery performance and after-market service to provide higher value at low cost (Gijoet al., 2019). Quality management helps in achieving quality goals and support managers in attaining quality improvement initiatives (Patyalet al., 2019). SS is a fact-based data-driven methodology that values defect prevention over
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defect detection (Pyzdek, 2003). It is known to be a highly effective quality improvement initiative for continuous and breakthrough improvements. The main purpose of reducing variation on a product or a service is to satisfy customers. The goal of SS is that only 3.4 DPMO of a million customers can be afforded for dissatisfaction. SS is widely recognized as data driven approach to reduce the wastage and errors in the process (Nicoletti, 2013;Lauxet al., 2017). Many firms also consider this as program under which number of projects run to address the bottom line issues (Hilton and Sohal, 2012;Albliwiet al., 2014). The project portfolio in SS is handled through a diverse team of members ranging from yellow or green belt to champion (Douglaset al., 2015). SS helps in developing the operational capability of a firm and can be strategic for many firms to address a particular issue (Manvilleet al., 2012). This approach is well structured and practiced by many of the firms. SS helps in reducing the variation present in a process (Albliwiet al., 2015;
Antonyet al., 2017). SS support the quality aspect of the products and processes through the application of tools and techniques in different phases (Antonyet al., 2017). Over the period of time SS has become a symbol of operational excellence for many firms. The SS culture indirectly helps firms to maximize the shareholder value by enhancing the customer satisfaction index (Ozkanet al., 2017;Ismyrlis and Moschidis, 2018). SS can help firms to attain the significant improvement at much lower cost and non–value-added activities can be further minimized with the help of structured SS approach (Prashar, 2014;Nullet al., 2019;Soundararajan, 2019). In many of the firms SS is found as management style of handling and deploying the projects and therefore continuous improvement (Pepper and Spedding, 2010; Lu et al., 2017). Entire SS approach is customer centric and improves the performance quality through the development of robust, cost-efficient and flexible processes (Antony, 2015). Apart from this, SS is applicable in different manufacturing environments ranging from make to stock to batch production to engineer to order (Shamsuzzamanet al., 2018). Additionally, literature also indicate that SS in not prevalent in large corporations but also in small and medium enterprises (Prasanna and Vinodh, 2013). Different organizations and industries view SS differently. Few organizations has defined it as approach, few as methodology, few as model, few as philosophy, few as program, few as strategy and few as system (Sreedharan and Raju, 2016). The range of applications of SS approach can be found across industries (Sreedharan and Raju, 2016), such as telecom (Thakkar, 2019), manufacturing (Patel and Desai, 2018), banking sector (Sunderet al., 2019) and IT sector (Mallali and Gopalkrishna, 2019).
The success and failure of SS projects depend on the teamwork and resource utilization (Juliani and Oliveira, 2019). The project tracking and review help firms to understand the progress status (Tangen, 2005). SS also acts as supporting element to culture of organization, where different department can work on a common problem (Mehrabi, 2012; Antonyet al., 2016a, b). The projects executed in the form of SS help firms to learn for the improvement and implement customer feedback in their systems (Schroeder et al., 2008; Zhuo, 2019). The performance measurement system can be easily deployed with the help of SS structure (Tangen, 2005;Mouraet al., 2019). SS also ensures the departmental transparency. SS helps in the development of suppliers through different projects carried over the period of time. SS projects do not only equip firms with tools and enhance the capability of problem solving, but also develop the mangers to drive the insights from the data and take logical decisions for day to day operations (Sinet al., 2010;Lauxet al., 2017). In a nutshell, SS helps in identifying the root cause of the problem through analytical tools and keep it in control.
Sigma,“σ”, is a letter in the Greek alphabet used by statisticians to measure the variability in any process. Motorola adopted the SS methodology in 1986, and emerged as a leader in quality and financial one-upmanship, and demonstrated its potential by winning the Malcolm Baldrige National Quality Award in 1988 (Patyal and Koilakuntla, 2016). Later many organizations like, Texas Instruments, Honeywell, Kodak, General Electric, ABB, Bank of America and Sony, have exhibited substantial financial returns because of the adoption of the SS methodology for various business processes (Montgomery and Woodall, 2008;Patyal and Koilakuntla, 2016).
Six Sigma
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There are two major improvement methodologies in SS: one for pre-existing processes and the other for new ones. These are DMAIC and DMADV (Lindermanet al., 2003). The DMAIC approach is used to meet the objectives of projects by improving an existing product, process or service. It is based on clear-cut measurements, identifying specific issues and providing solutions that can be measured (Sixsigmaonline.org, 2014). However, SS DMADV is deployed for designing a new product, process or service (Pyzdek, 2003). It intends to design products or services that are resource efficient, capable of very high yields regardless of complexity and volume, robust to process variability (Harry and Schroeder, 2000). The literature reported several variations of DMAIC in terms of number and type of phases instead of tools and techniques such as Project-DMAIC, Enterprise-DMAIC and DMAIC Report (Senapati, 2004).
Similarly, the literature reported different types of DFSS such as, DMADV, design characterize optimize verify (DCOV), identify design optimize validate, identify characterize optimize verify and DMADV (Tjahjono et al., 2010). The selection methods, tools and techniques varies at project, as well as enterprise levels (Wardet al., 2008). It helps in solving critical customer complaints, as the dissatisfied customer affects organizations in terms of loss of loyalty, business, and profit and also influences other customers’behavior (Dellande, 1995). Additionally, DMAIC methodology helps in reducing the number of customer complaints by identifying batch to batch variation in products which further helps in improving company performance. A large number of research studies highlighted the success of DMAIC application in the context of manufacturing and service (see,Table 1) for example, administrative, R&D, sales and marketing, health care (Dreachslin and Lee, 2007;
Mahanti and Antony, 2009;Firka, 2010;Gijoet al., 2011), thermal power plants (Kaushik and Khanduja, 2008), retailing (Kumaret al., 2008a), financial services (Kumar et al., 2008b), information technology management (Antony et al., 2012) and manufacturing process (Li et al., 2008;Roth and Franchetti, 2010;Tonget al., 2004). However, there is a dearth of research highlighting the application of SS in customer complaint reduction related to a chemical plant. The present study evaluates the application of SS in an industrial case study to explain its effectiveness in intricate situations.
3. Research methodology
In past the case study analysis approach has been used by researchers for many years across a variety of disciplines. The objective of case study technique is to explore key issues particular environment, circumstance or organization. Case study is an empirical investigation that explores a problem in its real-life context (Yin, 2009). This approach helps in collection and analysis of data in the context of the research and the ability to capture the dynamics of real-life situations (Hamelet al., 1993). The authors use a single case study approach applied to a single function as it meets the established objectives set by the authors. There are several reasons of adopting case study approach in comparison to other methodologies (Merriam and Tisdell, 2015; andGijoet al., 2019). The case-study approach provides design and implementation versatility that is more sensitive to the dynamics of social phenomena than quantitative methods. It provides a means of analyzing complex social systems consisting of multiple variables of possible significance for understanding the phenomenon. This approach also highlights human thoughts, behavior and actions that would otherwise difficult to explore by other means.
This study has adopted a six-stage process for carrying out the case study methodology (Stake, 1995;Simons, 1980;Gijoet al., 2019).
(1) Define the issue to be discussed within the case study organization;
(2) Identify the appropriate problem-solving approach to be implemented for the particular problem
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Author/yrResearchobjectivesLevelof analysToolofanalysisApproach adoptedSettingMajorfindings Burchetal. (2016)Understandandshowcase howleanSSisappliedin logistics
FirmDMAICCasestudyLogisticsfirmfromUSAInthecase,qualityfunction deploymentandcauseeffect analysishasbeenused.LeanSS (LSS)hashelpedthefirminthe formoftimeandqualityofthe selectionofanewruggedized handhelddeviceforfieldworkers Gijoetal. (2014)DemonstrationofSS methodologyinimprovingthe fastyield
FirmDMAICCasestudyAutomotivefirmfrom IndiaSpecificationsrelatedproblems weredetectedandcorrected, whichhelpedtoimprovethefirst passyieldfrom85percentto 99percent.Toolslikeregression analysis,causeandeffectanalysis anddesignofexperimentswere applied,whichresultedinthetotal costsavingsupto$80,000. Further,ithelpedtoimprovethe customerperceptionaboutthe firm Baya(2015)Examineandimprovingthe processoffillingalongwith implementationofothertools FirmProcess capability and5S
SinglecaseFertilizercompanyfrom PortugalTheCpkindexhelpedthefirmto improvecustomersatisfactionby balancingthecorrectweightof fertilizerbags.Thishelpedthe firmtohavesignificantcost savingsandincreasedits competitiveness.Further, combiningSSwith5Sprovedto beanoperative,modestand simplewaytoimprovetheprocess (continued)
Table 1.
Six sigma review
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Author/yrResearchobjectivesLevelof analysToolofanalysisApproach adoptedSettingMajorfindings Lameijeretal. (2016)IdentifytheleanSS dimensionswhichaffect employeeandtop managementattitudes FirmCrosscase analysisMultiplecase studiesFourfinancialservice firmsandonehospital fromNetherlands (ServiceIndustry)
TheresponsetoLSSwilldepend onhowitisportrayedinthefirm. Thereismorevariationinthe employees’attitudesthanthe managers’.Employeeswhodonot wanttobepartofLSS,remain passive.DimensionslikeTQM, improvementstrategies,HRM andadditionalmetricsaremost commoninallthecasecompanies. Further,astructuredapproach, managementsupportforthe projectalongwithtraining, linkingleanSStohumanresource, arethecriticalfactors Prashar(2016)Identifythedefectsand processimprovement opportunitiesinmeterreading
StakeholdersDMAICSinglecaseElectricityproviderfirm fromIndiaThedevelopedprocessmetricsact asadegreeofcomparisonfor insideandoutsidebenchmarking. Identificationofthefinest practicesencouragessharingof informationamongtheutility serviceproviders.Thebilling errorsandmeter-reading reportingwasminimizedthrough rootcauseanalysis (continued)
Table 1.
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Author/yrResearchobjectivesLevelof analysToolofanalysisApproach adoptedSettingMajorfindings Antonyetal. (2016b)Examinethebasicchallenges, frequentlyusedtoolsand practices,benefitsalongwith firminfrastructureandits impactforfirmperformance FirmCross-case analysisCasestudyThreemanufacturing (Solarcell,electricaland compressor manufacturing)firms fromIndia
Fromthebarriers’side:Thefirms lackinunderstandingthe paybacksintheearlystagesofSS andhighattritionrateofblack beltexecutives.Fromthebenefits’ side:SShelpedthefirmsto improvetheprocessproductivity, reductioninmaterialinventory, decreaseinrejectionandrework attheshopflooralongwiththeon timedelivery.Commonlyused toolsare:SIPOC,fishbone diagram,hypothesistesting, controlchartsalongwithdotand boxplots.Allthethreefirms believethatSShadapositive impactontheirperformance (customersatisfaction, productivity,returnon investmentandproductquality) (continued)
Table 1.
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Author/yrResearchobjectivesLevelof analysToolofanalysisApproach adoptedSettingMajorfindings Antonyetal. (2016a)Determinethedisjointedclaim ofleanSSforspecificindustryFirm–ViewpointPublicsectorfromUKTheapplicationofLSSismore widelyspreadthanwhatpeople think.Therehasnotbeenenough evidencefortheuseofLSSinthe UK’spublicsector.Further,the author(s)highlightedifSScanbe combinedwiththecultureof continuousimprovementalong withgovernmentsupportand encouragement.Thismaybring outanefficient,integratedsystem inplace Bhatetal. (2016)Demonstratetheapplicationof leanSStomedicalrecords department
FirmDMAICCasestudyHospitalfromIndiaAfteridentifyingtherootcauses, theproblemwasvalidatedwith thehelpofleantools.Spaghetti, valuestreammappingand ANOVAwereappliedto understandthevalueaddedand non-valueaddedactivitiesina turnaroundtimeforthe preparationofmedicalrecords. Theturnaroundtimewasreduced from19minto8minandthe standarddeviationuptoone- tenth.Thisresultedinthe reductionofthework-in–process inventoryfrom40unitsto0atthe endofeachworkingday (continued)
Table 1.
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Author/yrResearchobjectivesLevelof analysToolofanalysisApproach adoptedSettingMajorfindings Guerreroetal. (2017)Identificationof manufacturingprocess difficultiesandopportunities forimprovement
FirmDMAICSinglecaseWoodfurniturefirm fromUSALeanSShelpedafirmtoreduce thedefectsupto25%alongwith reductioninwasteby13%.The DMAICmethodologyhelpedthe firmtoincreasesalesby14%in theveryfirstyear.LSSwillbe difficulttoconduct,ifthereare poorproceduresandquality managementsystem.Managers shouldhavesoundknowledgeof itsbenefits,structureand approachbeforeinvolvingtheir otheremployees Antonyetal. (2017)Criticallyexamineand evaluatethepotential applicationofleanSSinthe publicsector
FirmCrosscase analysisCasestudyPublicsectorfromUKLeanSSapproachescanhelpthe firmsinpublicsectortogenerate effectiveandcompetentprocesses whichcanenhancecustomer experienceandassessmentbyend consumersatdecreasedcosts Baldassarre etal.(2018)Developtheprocessfor enhancingthecompetenceof hospitalservicequalityto increasethepatient satisfactionandreducethe clinicalrisks FirmDescriptive statisticsSecondary andPrimary dataanalysis
SurgeryDepartmentin ItalianHospitalDevelopedprocessesleadto enhancementinoperationsby recognizingtheblocksandrisks. Innovativeorganizational processeswillhelptogaina competitiveadvantage (continued)
Table 1.
Six Sigma
methodology
and its
applications
Author/yrResearchobjectivesLevelof analysToolofanalysisApproach adoptedSettingMajorfindings Nooriand Latifi(2018)DeploySSapproachtoaid defectreductionandaugment thebottom-lineconsequences FirmDMAICand change management techniques
CasestudyAutomotivefirmfrom IranDMIACandchangemanagement havebeenappliedindefect reductioninthegrindingprocess ofautomotiveengine manufacturing.Managementof changehasbeenintegratedwith DMAICmethodology.Thebefore andaftercomparisonofSS implementation,showsthattotal $40,000hasbeensaved Gijoetal. (2018)ApplicationofleanSSfor achievingoperational excellence
FirmDMAICCasestudyAutoancillaryfrom IndiaGaugeR&Rstudyandotherdata driventoolshavebeenappliedto analyzethecase.Reworkand scrapcosthasbeenreduced drasticallyaftertheapplicationof leanSSandledtothesavingof INR1.41millionannuallyforthe company Guptaetal. (2018)Decreasetheprocessvariation ofbeadsplicewhichleadtothe wastageofmaterial
FirmDMAICCasestudyTyremanufacturing firmfromIndiaAfterdeployingtheDMAIC methodologyinthecasefirm,the standarddeviationhasreduced from2.17to1.69.Process capability(Cp)increasedto1.65to 2.95andprocessperformance capabilityindex(Cpk)enhanced from0.94to2.66,whichledtoa decreaseinthevariationofbead spliceintyremanufacturing (continued)
Table 1.
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Author/yrResearchobjectivesLevelof analysToolofanalysisApproach adoptedSettingMajorfindings Deithornand Kovach(2018)Demonstratehowtousethe leanSSmethodologyforlarge improvementgoals FirmDMAICCasestudyAkerSolutionsInc.(Oil andgasexploration serviceprovider)
IntheinitialphaseoftheleanSS project,focusandpatienceis important.Abigprojectwithan ambitiousgoalcanbeclassified intoasequenceofminorprojects. Thisapproachtoclassification willensurethetimelycompletion. Thebaselinemeasurementsare importantforthepurposeof comparison.LSShelpedthefirm tomakechangesinthebilling processapproximatelyby 50percent
Table 1.
Six Sigma
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(3) Implement the technique and collect all necessary data related to the issue under investigation
(4) Perform data analysis using applicable statistical tools and interpret key findings (5) Report the major findings of the study
(6) Convey the key lessons learned to key stakeholders and concentrate on what worked best and what did not work
This study made an attempt to study SS application for addressing the customer complaints pertaining to Chemical-X in an Indian chemical company. The authors have chosen an issue with a high impact on consumers so as to illustrate the advantages of using the SS approach to all stakeholders involved in the case study. The generality of a single case study is restricted;
however, every case adds to the amount of knowledge available to potential practitioners and researchers by recording the case experiences in the light of existing literature (Antonyet al., 2012). In this study the processes were analyzed, data were collected and various statistical methods and techniques were used to make inferences about the root causes. The key recommendations and issues faced throughout implementation were documented which will be useful for all future researcher. The project methodology has been shown inFigure 1.
4. Case study
The study was carried out at chemical company facing the issue of customer complaints, which was hampering the number of orders placed and was adversely affecting the company’s revenue. The company has most of its customers from foreign countries. The company under study is a tier 1 supplier to most of the related organizations. This company has a direct impact on the business of other organizations. Therefore, it is critical for the firm to reduce the number of complaints. The case discussed is about ABC Company (given name), a manufacturer of inorganic chemicals in India. The company produces chemicals with a wide range of its applications in textile, polymer, rubber, paint, pharmaceuticals, paper and pulp industries. In 1995, the company entered into a joint venture with one of the European chemical companies to strengthen their business. The joint venture resulted into the emergence of the company as a market leader in India for most of its product range. About thirty-five percent of its overall business comes from exports. Moreover, during the twenty- three year tenure of the joint venture, the organization has made significant improvements in various areas such as research, and development of new products, engineering and technology, and quality of products. Despite of the decent growth of the company, they have a significant number of customer complaints. The rising customer complaints, is one of the major concerns and it is badly affecting the quality of products. Owing to the inorganic nature of products, they are sensitive to environmental conditions, the raw material used, handling conditions and packaging material.
The company classified the customer complaints regarding different products broadly into three major categories as follows: (i) A type–quality (assay, lumps, and black particles);
(ii) B type–packaging (less pouch and low weight) (iii) C type–application based. For some of the products, complaints have reduced from the previous three consecutive years and for some other products, complaints have increased. The A-type complaints decreased from 8 to 6 two years back and then increased to 10 till last year. The A type customer complaints are considered critical to quality, as it has the maximum weightage in customer satisfaction.
Hence, an SS project was undertaken to investigate the root cause of customer complaints and achieve the highest level of customer satisfaction regarding Chemical X. The study involves collection of two types of data for analysis and interpretation, most of the primary data generated by brainstorming with the concerned process executives are used for the why–why
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analysis. Further, the how–how analysis is conducted for solving the lumps related customer complaints.
5. DMAIC approach 5.1 Define phase
A project team was formed with a production manager as the black belt, a site engineer, two production supervisors and a marketing executive as team members. The managing director of the company was identified as the champion for the project. The problem was identified on the basis of three types of complaints, viz., A, B and C. There was a need to identify the reasons associated with various complaints by brainstorming, and by actual process monitoring. To start the project, first one has to set a timeline to carry out the project and again to compare with previous results. Therefore, it was necessary to develop a project charter.
The project charter is the planning team’s concise statement of core goals, values and intent. It helps the team in order to provide the ultimate direction for everything that comes next. Mostly, the executives of any company are busy up to neck in their daily challenges of
LITERATYRE REVIEW
CASE STUDY
DEFINE
MEASURE
ANALYSE &
IMPROVE
CONROL
RECOMMENDATION & IMPLICATION
CONCLUSION & FUTURE SCOPE
Problem Identification Activity Chart Project Charter SIPOC Diagram
Measurement System Analysis Data Collection Plan
Classification of Customer Complaints Process Capability Analysis
Why- why Analysis How- How Analysis
Taguchi Design for Experimentation Validation Trails
Monitoring with checklist Establishing standard measures RESEARCH METHODOLOGY
Figure 1.
Structure of the project undertaken
Six Sigma
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building the site. In this environment, it is obvious to forget why you are doing, what you are doing and they can lose sight of their original priorities. At the end of the project, it feels as if the decisions you are making firmly support the overall objectives or not. A well-written project charter is a powerful daily tool for judging the effectiveness of a development effort. It becomes a compass to keep the team firmly pointed at the goals established when you started the journey. A good project charter becomes a daily reference point for settling disputes, avoiding“scope creep,”judging the potential utility of new ideas as they arise, measuring progress. This helps in keeping the development team focused on the end-result. At minimum, a project charter should define the content scope, budget, schedule and technical aspects of the project. The best project charter is short and to the point, often outlines the major design or technical features. The finished project charter should contain the goals statement from the planning phase, as well as the structural details of the site. The team prepared a project charter in that 5 phases were divided over the period of 5 months to control the lumps formation. It was found that Chemical-X and other products were passing through a hard phase of customer satisfaction. Hence, for identifying the root cause and eliminate them, a project charter was developed. (seeTable 2). The process map for DMAIC was plotted for the requirements at the define measure, analyze, improve and control phase.
5.2 Measure phase
This phase of SS includes primary data collection and presents status of the process. It also lays a foundation for identifying and gathering the causes of the basic problem and helps to understand the problem more clearly. It was required to classify the complaints and their frequency in the last three years to see the trend. The complaints were classified into three categories namely quality, packaging and application. The quality based complaints are mainly due to not meeting customer specifications. Packaging related complaints are mainly due to the wrong selection of material for dispatching the product, less pouches and wrong labeling and wrong weight. The application based complaints are due to incompatibility of the Chemical-X to the customer and firm’s processes.
Further, the data were collected for the purity of Chemical-X to understand, if there was any measurement system issues in the process. For the measurement system analysis (MSA), the data were collected from 3 operators with 10 samples. For convenience, the author(s) have classified the customer complaints regarding Chemical-X as A, B and C. The MSA was
Problem statement Opportunity statement
The Chemical-X is one of the core products and after the grinding and packing of Chemical-X chips, it absorbs moisture and leads to lumps formation, which was the major reason of in-house rejection, as well as customer complaints
The elimination of lumps formation in Chemical-X powder will lead to no in-house rejection and increase in customer satisfaction
Goal statement Project scope
Eliminate the lumps formation thereby saving INR 7 lakh per annum in Chemical-X powder
(1) Temperature stabilization (2) Controlled environment (3) NaCl absorption to environment (4) Controlled humidity
Project plan Team selection
Define phase–two weeks Measure phase–six weeks Analyze phase–four weeks Improve phase–four weeks Control phase–four weeks
Six-member team from (1) R&D
(2) Marketing (3) QA
(4) Production department Table 2.
Project charter for Chemical-X
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deployed to minimize the error in measuring the whiteness of powder and lumps formation.
The gage repeatability and reproducibility (R&R) was analyzed for the measurement system and found within limits (seeTable 3). The measurement system indicates the soundness of equipment and operators in the entire measurement system for Chemical-X.
Moreover, it is fundamental to understand the value chain of any product to simplify and address the current problem. Therefore, a SIPOC (Supplier, Input, Process, Output and Customer) diagram was developed, and is presented inFigure 2.
The purity and temperature during production and grinding are the critical parameters of Chemical-X manufacturing process. Therefore, temperature in the production area of grinding and after grinding along with related humidity was measured.
5.3 Analyze and improve phase
The Analyze and Improve phase of DMAIC plays an important role in the execution of any SS project to critically analyze the issues, to identify the root cause, and to help process
Supplier ABC Ltd
Part Name Chemical-A Gage Name MetroOhm Tester Appraiser Name(s): Sunil, Kapil
and Pawan
Part No. 10 Gage No. II
Characteristic Gage Type Manual
Specification 99.00 % min. Least Count 0.01
No. Of parts = 10 No. Of Trials = 3 From Data Sheet (Appendix)
R = 0.04 X diff = 0.00784 Rp = 0.82
Measurement Unit Analysis % of Variation
Repeatability-- Equipment Variation (EV) Percent Equipment Variation
EV = R. K1
= 0.04*0.5908
= 0.025
Trials K1
2 0.1
3 0.6
% EV = 100(EV/TV)
= 9.61
Reproducibility-Appraiser Variation (AV) Percent Appraiser Variation
AV = ((Xdiff*K2)^2-(EV)^2/nr)^1/2
= 0.006
Where: N = no. of parts r = no. of trials
Appraiser 2 3
K2 0.7071 0.5231
% AV = 100(AV/TV)
= 2.49
Repeatability & Reproducibility (R& R) Percent Gage Repeatability &
Reproducibility Variation R&R = ((EV)^2+ (AV)^2)^1/2
= 0.026
% R&R = 100(R&R/TV)
% R&R = 9.93
Part Variation (PV) Percent Part Variation
PV = Rp* K3
= 0.259
Parts K3
5 0.4
6 0.4
7 0.4
8 0.3
9 0.3
10 0.3
% PV = 100(PV/Tol)
% PV = 99.51
Total Variation (TV)
Number of Distinct Categories that can be distinguished (ndc)
TV = ((R&R)^2+ (PV)^2)^1/2 = 0.260 ndc = 1.41x(PV/GRR)
ndc = 14.13 ≈ 14
Table 3.
Gage repeatability and reproducibility
Six Sigma
methodology
and its
applications
observation and relative analysis. If the team of SS applies half-analyzed solutions, it may result into more waste, more consumption of resources and more variation instead of reducing them. The root cause of the problem was identified in this phase. This section includes Taguchi design, why–why analysis and how–how analysis which were conducted for solving lumps related customer complaints.
The process capability for Chemical-X was computed and it showed that the process was left centered, along with a scope of improvement in Cp and Cpk. The poor value of Cpk50.18 indicated that the process was not on the target and consistent. Later, the capability (Cpk) has improved to 1.37 (seeFigure 3) which indicates a more stable process. The root cause for customer complaints was identified through why–why analysis (seeFigure 4) and how–how analysis (seeFigure 5). Therefore, Taguchi design was used determine the factors and factor levels for the manufacturing process of Chemical-X.
Installation of new rotary drum filter for new batch processing Incoming
inspection by quality department
Issue of raw material from store to production in specified ratio
Grinding of Chips Vacuum and Dryer (65 °C)
Packing of the Chemical-X powder
Communication to production for acceptance or rejection of lot
Sampling and testing for specifications (QC)
Supplier Input Process Output Customer
Cooling (Room Temp.-25 °C) R.K Trading
Sai Chemicals Avani Chemicals J&H Chemicals IOCL Reliance Industries
SO2 Gas Zinc Dust Temperature Pressure Reaction Time Cooling Time
Power formation Fine Grade
Super Grade Extra Grade
Marketing Department Textile Industry Pharmaceutical Industry
Figure 2.
SIPOC of the operations in Chemical- X production
Figure 3.
Process capability of Chemical-X before vs after
IJPPM
The improve phase also includes the check on process capability.Figure 3indicates that the overall capability (Cpk) has improved from 0.18 to 1.37 which is toward a more stable process.
5.3.1 Identification of factors and factor level using Taguchi design.After the application of the brainstorming technique with all the employees concerned and after establishing cause and effect relations between input-parameters and output-parameters of the Chemical-X
Problem Statement
Why 1
Why 2
Why 3
Why 4
Customer complaints are hampering the business
Why lumps are forming in the product?
-Finished product kept in sunlight before dispatch
Why the product is kept in sunlight?
-To get the product to normal temperature.
Why get the product to normal temperature?
-Grinding of the Chemical-X at 40 to 50 °C
Why chemical-X is grinded at 40 °C to 50 °C -It can be packed immediately
Why 5
Why it needs to be packed immediately?
-For meeting the production and marketing target
Why is it necessary to meet the target?
-To meet the revenue target.
Why 6
Mechanism Ensure Chemical-X chips are allowed to cool and set for 24 hours before grinding.
Control Control temperature of grinding machine &
material.
Material and Method Ensure fixing of sieve of 3mm. Alternate packing material to avoid moisture. Ensure that the sieve is not broken.
Supervision Ensure the grinded powder/rice to be packed in intermediate carboy & kept 24 hours before final packing.
Monitoring Rate of grinding should be within 430kg/hr or within specified limits.
Analyze Analyze sample after each grinding lot for lumps/chips presence.
Figure 4.
Why–why analysis for customer complaints in chemical-X
Figure 5.
How–how analysis for customer compalints in chemical-X
Six Sigma
methodology
and its
applications
manufacturing process, the most significant four process parameters were identified as controlling parameters along with the relevant levels presented inTable 4.
5.3.2 Development of experimentation design with the help of Minitab Software.The factors above and levels for the Chemical-X manufacturing process were used to develop the L9 Taguchi design with the help of Minitab Software. R1, R2 and R3 represent 3 trials presented in Table 5. In this study, the objective was to have a minimum number of customer complaints and rank the same. Table 6 indicates that humidity is least important for Chemical-X as compared to other factors.Table 7presents the analysis of variance (ANOVA) and indicates that holding time after grinding (HTAG), shift type and TAG affect the
Sr. No Name of the factor Notation Unit of measure No. of factor levels
Factor levels
1 2 3
1 Holding time after Grinding HTAG Hr 3 18 24 28
2 Humidity Humidity % 3 68 72 76
3 Shift Shift – 3 1 2 3
4 Temperature after grinding TAG 8C 3 40 43 46
HTAG Humidity Shift TAG R1 R2 R3
18 68 1 40 2 2 3
18 72 2 43 4 5 6
18 76 3 46 6 7 5
24 68 2 46 5 4 5
24 72 3 40 4 3 3
24 76 1 43 2 2 3
28 68 3 43 4 3 3
28 72 1 46 4 2 3
28 76 2 40 4 3 5
Level HTAG Humidity Shift TAG
1 4.444 3.444 2.556 3.222
2 3.444 3.778 4.556 3.556
3 3.444 4.111 4.222 4.556
Delta 1.000 0.667
