UNIT- III TQM TOOLS & TECHNIQUES - 1 CCET MECHANICAL ENGINEERING UNIT- III TQM TOOLS & TECHNIQUES - 1 Prepared by B.BALASUBRAMANIAN ASSISTANT PROFESSOR CCET B.BALASUBRAMANIAN

SEVEN TRADITIONAL TOOLS OF QUALITY (Q-7 TOOLS) Check sheets Histograms Cause and effect diagrams Pareto diagrams Stratification analysis Scatter diagrams Control charts

Tool 1: CHECK SHEET A check sheet also known as tally sheet Used for systematic data gathering and registering To get a clear view of the facts To track how often something occurs It is tailored for each situation/application Used to indicate the frequency of certain occurrences

CHECK SHEET

Tool 2: HISTOGRAM A histogram is a bar chart/ diagram/graph It shows a distribution of variable quantities or characteristics Graphical distribution of the numerical data Data are displaced as a series of rectangles of equal width and varying heights Shows where most frequently occurring values are located and the data distributed Tool for determining the maximum process results Quick review of features of a complete set of data

HISTOGRAM

Tool 3: CAUSE AND EFFECT DIAGRAM It is also called as fish bone diagram or Ishikawa diagram It is a graphical chart to list and analyze the potential cause of a given problem and its effect It consists of a central stem leading to the effect with multiple branches coming off the stem listing the various groups of possible causes of the problems Used in research, manufacturing, marketing, office operations, services etc.

CAUSE AND EFFECT DIAGRAM

Tool 4: PARETO DIAGRAM It is a diagnostic tool commonly used for separating the vital few causes that account for a dominant share of quality loss Pareto principle states that a few of the defects account for most of the effects Also called as 80/20 rule and as ABC analysis which means only 20 % of problems (defects) account for 80% of the effect Is a method of classifying items, events or activities according to their relative importance Priorities problems based on its relative importance Risk assessment technique from activity level to system level

PARETO DIAGRAM

Tool 5: STRATIFICATION ANALYSIS Analysis of data by grouping it in different ways Segregating a group of measurements, observations or any data into several sub-groups on the basics of certain characteristics These stratified data are used for identifying the influencing factors Simple and very effective QC tool for improving the quality

STRATIFICATION ANALYSIS CCET MECHANICAL ENGINEERING STRATIFICATION ANALYSIS B.BALASUBRAMANIAN

Tool 6: SCATTER DIAGRAM Graphical device to depict the relationship between two variables Horizontal axis – cause Vertical axis – effect Diagram displays the paired data as a cloud of points Density and direction of the cloud indicate how the two variables influence each other Displays what happens to one variable when another variable is changed Used to understand why particular variations occurs and how they can be controlled

SCATTER DIAGRAM

Tool 7: CONTROL CHART Most widely used tool in statistical process control (SPC) Graph that displays data taken over time and the variations of this data It illustrates the dynamic performance (performance over time) of the process Based on a series of random samples taken at regular intervals It contains three horizontal lines that remains constant over time: A center A lower control limit (LCL) An upper control limit (UCL) If a point lies inside UCL and LCL then the process is in control If the point lies outside UCL and LCL then the process is out of control

CONTROL CHART

TYPES OF CONTROL CHARTS Control charts for variables - for measurable data such as time, length, temperature, weight, pressure, etc. Control charts for characteristics - for quantifying data such as number of defects, typing errors in a report, etc.

NEW SEVEN MANAGEMENT TOOLS Affinity (KJ) diagram Relationship diagram Tree diagram Matrix diagram Decision tree (PDPC) Arrow diagram (PERT) Matrix data analysis

Tool 1: AFFINITY DIAGRAM A tool to collect a large amount of verbal expressions and organize them in groups according to natural relationship between individual items Also known as KJ diagram Special type of brainstorming tool Provide a visual representation of large amount of ideas Used to extract large amount of useful information from few or scattered data or from unrelated ideas Used to understand and organize problems that are not clear

AFFINITY DIAGRAM

Tool 2: RELATIONSHIP DIAGRAM Tool for finding causes to a problem Same as cause and effect diagram Not only clarifies the relationship between cause and effect but also between various causes Graphical representation of all factors in a complicated problem, system or situation Used to identify key problem from a list of important problems, identify the root cause of existing problems and identify key factors needed to make a decision

RELATIONSHIP DIAGRAM

Tool 3: TREE DIAGRAM Systematically breaks down a topic into its components elements and shows the logical and sequential links between these elements Systematically outlines the complete spectrum of paths and tasks that must be carried out to achieve a goal Used to develop a systematic, step by step, strategy to achieve an objective

TREE DIAGRAM

Tool 4: MATRIX DIAGRAM Systematically organize information that must be compared on a variety of characteristics in order to make a comparison, selection or choice It depicts the relationship between two sets of factors in the form of a table or a matrix Also known as quality table and it is the starting point in building a house of quality

MATRIX DIAGRAM

Tool 5: PROCESS DECISION PROGRAME CHART (PDPC) Also known as decision tree Planning tool to outline every conceivable and likely occurrence in any planning Forces proactive thinking on what can go wrong with one’s plan and what would one do to overcome the effect of such adverse occurrences Helps to anticipate undesirable occurrences and enables one to prepare with plans to neutralize their effect Used in new product development, building and equipment and data processing programs Used in decision making when the task is new, complex and unique

DECISION TREE

Tool 6: ARROW DIAGRAM It is a graphical description of the sequential steps that must be completed before a project can be completed PERT (Program Evaluation and Review Technique) and CPM (Critical Path Method) charts are the best known arrow diagram Planning tool that determines the critical path of a process or a project Indispensible for long term projects such as the construction of a plant or the development of new products

ARROW DIAGRAM

Tool 7: MATRIX DATA ANALYSIS DIAGRAM Very much similar to a matrix diagram A difference is that numerical data is used instead of symbols indicating the existence and strength of relationship Only tool among the New Seven Management Tools which uses numerical data and produces numerical results Used in studying the parameters of production processes, in analyzing market information, in finding links between numerical and non numerical variables

MATRIX DATA ANALYSIS DIAGRAM

SIX SIGMA (6σ) Six standard deviation from mean Improve the capability and reduce the defects in any process It strive for perfection It allows only 3.4 defects per million opportunities or 99.999666 % accuracy Here a defect can be anything like incorrect customer bill It improves the process performance, decrease variation and maintains consistent quality of the process output. This leads to defect reduction and improvement in profits, product quality and customer satisfaction It incorporates the basic principles and techniques used in business, statistics and engineering Its objective is to achieve zero defects products

SIX SIGMA PROCESS Define Measure Analyse Improve Control Though it is originated from manufacturing field, now it is applied to non-manufacturing processes only such as service, medical and insurance procedures, call centers, etc.

BENCHMARKING “The process of identifying, understanding and adapting practices and processes from organisations anywhere in the world to an organisation to improve its performances” Systematic method by which organization can measure themselves against the best industry practices The process of barrowing ideas and adapting them to gain competitive advantage

REASONS TO BENCHMARKING (OBJECTIVES) Aims at goal setting process to facilitate comparison with the best Aims at motivating and simulating company employees towards the goal of continuous quality improvement Aims at external orientation of the company Aims at identifying a technological breakthrough Aims at searching for industry best practices

TYPES OF BENCHMARKING Based on the object to be Benchmarked Product benchmarking Performance benchmarking Process benchmarking Strategic benchmarking Based on the organisations against whom one is benchmarking Internal benchmarking Industry benchmarking Competitive benchmarking Best in class benchmarking Relationship benchmarking

BENCHMARKING PROCESS Planning - what is to be benchmarked? What shall we compare? How will the data be collected? Analysis – careful understanding of current process practices as well as those of benchmarking partners Integration – careful planning to incorporate new practices in the operation Action Maturity – best industrial practices are incorporated in all business processes

FAILURE MODE AND EFFECT ANALYSIS (FMEA) It is a preventive measure to systematically display the causes, effect, and possible actions regarding observed failures It objective is to anticipate failures and prevent them from occurring FMEA prioritises failures and attempts to eliminate their causes Never ending process improvement tool

TYPES OF FMEA System FMEA Design FMEA Process FMEA Service FMEA Equipment FMEA Maintenance FMEA Concept FMEA Environment FMEA

STAGES OF FMEA (METHODOLOGY) Specifying possibilities Quantifying risks Correcting high risk causes Re-evaluation of risk

FMEA PROCEDURE Identify failure modes (potential failure) Describe the potential failure effects(Result of failure mode) Establish a numerical ranking for the severity (S) of the effect Identify the potential causes/mechanisms of failure Enter the probability of occurrence (O) factor Determine the likelihood of detection (D) Review risk priority number (RPN = S × O × D ) Determine recommended action