งานนำเสนอเรื่อง: "The Pareto Principle Vilfredo Pareto was an economist who is credited with establishing what is now widely known as the Pareto Principle or 80/20 rule."— ใบสำเนางานนำเสนอ:
1 The Pareto PrincipleVilfredo Pareto was an economist who is credited with establishing what is now widely known as the Pareto Principle or 80/20 rule. When he discovered the principle, it established that 80% of the land in Italy was owned by 20% of the population. Later, he discovered that the pareto principle was valid in other parts of his life, such as gardening: 80% of his garden peas were produced by 20% of the peapods.
2 The Pareto Principle Some Sample 80/20 Rule Applications 80% of process defects arise from 20% of the process issues.20% of your sales force produces 80% of your company revenues.80% of delays in schedule arise from 20% of the possible causes of the delays.80% of customer complaints arise from 20% of your products or services. (The above examples are rough estimates.)
3 The Pareto DiagramGraph that ranks data classifications in descending order from left to rightPareto diagrams are used to identify the most important problemsAdvantage: Provide a visual impact of those vital few characteristics that need attentionResources are then directed to take the necessary corrective action
4 The Pareto DiagramHelps a team focus on causes that have the greatest impactDisplays the relative importance of problems in a simple visual formatHelps prevent “shifting the problem” where the solution removes some causes but worsens others
5 Constructing a Pareto Diagram Steps:Determine the method of classifying the data: by problem, cause, type of nonconformity, etcDecide if dollars (best), weighted frequency, or frequency is to be used to rank the characteristicsCollect data for an appropriate time interval
6 Constructing a Pareto Diagram Steps cont’d:Summarize the data and rank order categories from largest to smallestCompute the cumulative percentage if it is to be usedConstruct the diagram and find the vital few
7 Pareto diagram 50% reduction Number of defectsPercent of components50% reductionPareto diagram can be used to identify the degree of severity of quality problems. To eliminate defects and improve the operation, this tool can help us to make decision that which problems should be solved first.
19 The Box Plot (HW4)The data set of N = 90 ordered observations as shown belowFind the dispersion of data using a box plot (i.e. calculate Q1, Q2, Q3, Outlier, find the skewness of the dispersion)Compare the result obtained from (1) with histograms (find mean, SD, skewness of histograms)30, 171, 184, 201, 212, 250, 265, 270, 272, 289, 305, 306, 322, 322, 336, 346, 351, 370, 390, 404, 409, 411, 436, 437, 439, 441, 444, 448, 451, 453, 470, 480, 482, 487, 494, 495, 499, 503, 514, 521, 522, 527, 548, 550, 559, 560, 570, 572, 574, 578, 585, 592, 592, 607, 616, 618, 621, 629, 637, 638, 640, 656, 668, 707, 709, 719, 737, 739, 752, 758, 766, 792, 792, 794, 802, 818, 830, 832, 843, 858, 860, 869, 918, 925, 953, 991, 1000, 1005, 1068, 1441
20 Cause-and-Effect Diagram It was developed by Dr. Kaoru Ishikawa in 1943Picture composed of lines and symbols designed to represent a meaningful relationship between an effect and its causesEffect (characteristics that need improvement) on the right and causes on the left
21 Cause-and-Effect Diagram Enables a team to focus on the content of a problem, not on the history of the problem or differing personal interests of team membersCreates a snapshot of collective knowledge and consensus of a team; builds support for solutionsFocuses the team on causes, not symptomsUsed to investigate either a “bad” effect and to take action to correct the causes or a “good” effect and to learn those causes responsible
22 Cause-and-Effect Diagram Advantages:Analyzing actual conditions for the purpose of product or service quality improvementElimination of conditions causing nonconforming product or service and customer complaintsStandardization of existing and proposed operationsEducation and training in decision-making
23 Cause-and-Effect Diagram There are 3 types of C&E diagramDispersion Analysis (การวิเคราะห์การกระจายหรือความแปรผัน)Cause Enumeration (การวิเคราะห์รายการสาเหตุ)Process Classification (การจำแนกตามกระบวนการ)
24 Cause-and-Effect Diagram Steps in the construction of aCause-and-Effect Diagram:Identify the effect or quality problemDetermine the major causesDetermine all the minor causes. Request a brainstorming sessionOnce the diagram is complete, evaluate it to determine the most likely causesDevelop solutions
31 Cause-and-effect diagram Cause-and-effect diagram with possible causesIs the cause-and-effect diagram good enough for solving the problem?How can we profoundly analyze and quantify the relationship between causes and effects?
32 Cause-and-effect diagram Cause-and-effect diagram after further study
33 Scattering diagramThe result of investigating the conveyer speed (cause) and the severed length (effect) as shown above
36 Previous 6 QC tools Static form of presentation Check sheetHistogramPareto diagramCause-and-effect diagramScattering diagramConsolidate data, แสดงลักษณะภาพรวมของข้อมูลให้ชัดเจนและมีความหมายยิ่งขึ้น (เช่นรูปแบบการกระจายตัวของข้อมูล)Indicate problem areas, บ่งชี้ให้เห็นถึงลำดับความสำคัญของปัญหาStatic form of presentationShow potential causes of defects affecting quality problem areas, แสดงให้เห็นถึงสาเหตุที่เป็นไปได้ของปัญหาที่มีผลต่อคุณภาพแสดงข้อมูลในช่วงเวลาหนึ่งๆ ไม่แสดงการเปลี่ยนแปลงของค่ามูลตามช่วงเวลา หรือ ล๊อตการผลิตShow quantitative relationship between causes and defects, แสดงความสัมพันธ์ระหว่างตัวแปรที่เป็นสาเหตุและปัญหาที่มีผลต่อคุณภาพ