2 History of quality management Early 1920Scientific management (Taylor, Gilbreth)1920sStatistical process control (Shewart)1930sAcceptance sampling (Dodge, Roming)1940sMilitary standards introduced1950sQuality management in Japan (Deming, Juran)1960sTaguchi method, and quality tools1970sQuality becomes strategic (USA)1980sIntroduction of LEAN, TQM, Baldrige Award1990sReengineering, Six Sigma2000sSupply chain management, improvement of supplier development, LEAN, Six sigma become popular, contingency theory
3 Quality and taylorism Basics of taylorism Quality effects: The whole process is divided into short steps (division of labor)It is not the worker who determine the process/movements -specialist do that (task management)Workers are selected and trained for workStandard movements and tools, detailed instructions (standardization)Quality effects:Product and process design were separated from the repair of productWorkers were not responsible for repairing of productQuality control department was established to control the product at the end of the processThe responsibility for quality were spread over in the company
4 DemingNot just worker but managers have the responsibility for establishing qualityWorkers responsible for special problemsManagers responsible for the whole system (proper methods, equipments, motivation system etc.)Quality improvement must be divided between the two level
5 JuranQuality problems are rooting in insufficient and ineffective planning for qualityIn traditional way:Planning determine the tools for producing goods20% of the operating process is waste, it is planned into the product or processInstead of quality improvement they only do quality controlJuran trilogyPlanningControlImprovement
6 IshikawaDemocratizing statistics: everyone is responsible for statistical analyzes,total involvement of the operating employees in improving qualityBasic 7 tools of qualityProcess map – flow chart, step of processCheck sheet – to collect errors for analyzesHistogram – graphic representation of dataScatter Diagrams – examine the relationship between variables (what cause the problem)Control Chart – is the process stable or notCause-and-effect (Ishikawa) diagram – find all reason of the problem, directed tool for find all causesPareto Chart – prioritize causes, determine problems must be focused on
7 Feigenbaum Father of Total Quality Control (TQC) the entire organization should be involved in quality improvementThe quality is poorIf the product is designed incorrectly (engineering)If the product is released in the wrong marketIf the customer relationship is not proper. (marketing)3 steps of improvement4 deadly diseases
8 Crosby Crosby’s four theorem Quality is the conformance to the requirements of customers. The whole system must be developed according to this approach.The main goal is zero-defect. Do the right product at the first time.Thus the applied method for quality assurance is prevention not control.Quality can be a source of profit. Quality costs must be evaluated, and on the basis of these costs, corrective actions should take place.
9 TaguchiQuality definitions: quality is measured in terms of loss to society if the service not performed as expected.Quality Loss Function (QLF): any deviation from target value results in loss to societyRobust Design: products should be designed to be defect-freeConcept design (technology and process choices)Parameter design (select parameters which have an effect on quality – amount of training, heights of a paper)Tolerance design (deals with decrease variation in order to fulfill the specification limits – use a higher-grade materials)
10 QLF (Qualtiy Loss Function) L=K*V2K – constant, andV2- mean squared dviation from target valueK=C/T2C - unit repair costT – tolerance intervalLSLTarget valueUSL
11 Exercise - QLFSuppose the cost to repair a radiator on an automobile is $200. Compute the QLF for losses incurred as a result of a deviation from target setting where a tolerance of 6±0,5 mm is required and the mean squared deviation from target is (1/6)2.Solution:K=200/0,52=800L=K*V2=800*(1/6)2=$22,22/unit
12 TAGUCHI PROCESS 1. Problem identification 2. Brainstorming session identify factors, its settings, interactions,Control factorNoise factorIdentify objectivesThe less is betterNominal is bestThe more is the betterExperimental designOffline experimentation (number of replications)ExperimentationOrthogonal array (determined by the number of factors and levels)Record the resultCompute average performance for each factorShowing the best outcomesAnalysis (which level of each factor is the proper one)Confirming experiment (validate results)
13 Contingency theoryThere are no schemes, firms do not have to use only one quality approachSuccessful firms adopt aspects of each approach that help them improve, understand them, and apply them creatively.It depends on the situation which approach is the best.