Six Sigma Green Belt Part 7

Transcription

1 Six Sigma Green Belt Part 7 Root Cause Analysis 7-1

2 Cost and Value In the economic battle of competition between organizations producing similar products or services cost is the ultimate measure. Green Belts must be cost conscious and value oriented to perform in the best interests of the organization. 7-2

3 Cost The cost of anything is the sum of the labor, raw materials, and overhead used to produce it. The minimum cost required to accomplish the functions desired is necessary cost; any cost above this is unnecessary. 7-3

4 Cost Variable Costs Variable cost is directly associated with the production of a product: Direct labor Direct materials $1, $1, $1, $ $ $ $ $ Units Produced 7-4

5 Total Cost Fixed Costs $ $ $ $ $50.00 $ Units Produced Fixed cost is not affected by a change in level of production. 7-5

6 Total Cost Total Costs $1, $1, $1, $1, $ $ $ $ $ Units Produced 7-6

7 Revenue Revenue Income received from each unit sold. $1, $1, $1, $1, $1, $ $ $ $ $ Units Sold 7-7

8 Break Even Point at which total costs equals total revenue. $1, $1, $1, $1, $1, $ $ $ $ $0.00 Breakeven Point Loss Units Surplus 7-8

9 Practice Our organization currently provides 100,000 units per year. Using the present method our annual costs are: Engineering: $2,000 Tooling: $12,000 Installation: $4,000 The variable cost is $3 per unit. Fixed Costs 7-9

10 Practice Continued A six sigma green belt has suggested a modification based on DMAIIC. This is designed to replace the current process. The costs are as follows: Engineering: $25,000 Special Equipment: $35,000 Training: $5,000 Re-layout: $10,000 Fixed Costs The Variable cost per unit using this method is $2.05 per unit. 7-10

11 Practice Question a. Which is the better alternative under current conditions? b. Determine the break over point between the two alternatives. c. What assumptions are we making? d. How much more do we make at the same production/sales level (if anything) with the improved method? 7-11

12 Root Cause Analysis All organizations have problems that plague their operations, reduce profits, and create customer dissatisfaction. We called many of these special causes of variation. Most organizations try to fix these problems quickly without ever finding what caused them in the first place, making the problems reappear. Root cause analysis is the process of finding and eliminating the cause, which would prevent the problem from returning. Only when the root cause is identified and eliminated can the problem be solved. 7-12

13 Process Definition A process is a set of conditions or set of causes which work together to produce a given result. It includes: Inputs, Outputs, Transformations, and Feedback. A process is any work that meets the four criteria: it is recurrent; it affects some aspect of organizational capability; it can be accomplished differently so as to make contribution to customer or/and profit; it involves co-ordination. Inputs Process Outputs Suppliers Customers SIPOC Model 7-13

14 SIPOC A method to assist in developing the flow on a process map is SIPOC Suppliers: Who supplies the inputs to do the job? Inputs: What are the products/services that your suppliers give you? Process/Sequence: What are the steps to convert the inputs to outputs? Outputs (products or services): What products or services are produced? Customers: Who receives your products and services? What do they need? What are their requirements? 7-14

15 Flowcharts A flowchart is a graphical representation of a process The first step in many process improvement projects is to create a flowchart 7-15

16 Flow Charts Map of the process showing elements such as Operations Decisions Delays Storages Handling Information Flow 7-16

17 Questions to ask: a. Why b. When c. Where d. Who e. How f. Why Process Analysis Using Flow Chart??? 7-17

18 Swim Lane Flow Chart Value Stream Map 2013 IIE and Aft Systems, Inc. 7-18

19 University Travel Process Employee Desires to Travel Verifies with Dept. Head Yes Employee Completes Request to Travel Form No Process Ends Dept. Head Approval No Process Ends Yes Employee Travels Process Ends Dean Approval No Process Ends No Yes Business Office Encumbers Funds Yes President Approval Yes VP Approval No Process Ends 7-19

20 Check Sheets Check sheets are used to record data. They are simple to use. They are: Visual Easy to Interpret Organize Data Collection Check sheets are designed, structured formats for recording process data in a manner that can reveal underlying patterns 7-20

21 Check Sheets Check Sheets are data gathering tools that can be used in forming histograms and Pareto charts Check sheets are a form used to record the frequency of occurrence of certain product or service characteristics Check sheets can be either tabular or schematic 7-21

22 Standard Check Sheet Design This check sheet helps to gather data on quality problems actually experienced Characteristic Performance Measurement Tally Total (What Could Go Wrong) Standard Frequency 7-22

23 Sample Check Sheet Apparel Manufacturing Potential Problem Observed Defective Frequency Inside out Machine broken No operator No raw material No thread Side seam mismatch Thread color Torn material Upside down Wrong needle

24 Sample Check Sheet Incoming Calls Date: Time Tally Total 9:00-10:00 10:00-11:00 11:00-12:00 12:00-1:00 1:00-2:00 2:00-3:00 3:00-4:00 4:00-5:

25 Sample Check Sheet 7-25

26 Pareto Analysis Pareto Analysis reflects the frequency or impact of problems. The actual analysis can appear either as a table or as a bar chart It is a guide to selecting opportunities and prioritizing 0 H B G A I D F E C Problem 7-26

27 Pareto Principle Derives from the Rule: 80% of the problems are due to 20% of the causes Identify problems to study Identify most likely causes Point out significant frequencies or costs Based upon Juran s work» Significant Few and the Trivial Many 7-27

28 Cause-Effect Diagram Tool for organizing team s knowledge about a process in effect it is organized or structured brainstorming Graphical picture of what is known about the process Communication tool Named after Dr. Ishikawa 7-28

29 Ishikawa Diagram The cause and effect diagram assists in reaching a common understanding of the problem and exposes the potential drivers of the problem 7-29

30 Typical Categories for Branches Manufacturing Methods Materials Equipment People Environment Service Procedures Processes Policies People 7-30

31 Sample Cause Effect Diagram METHODS MACHINE Operator Mat'l ID Training Tension Information Placement Set Up Specs Wrong Clearance Calibration Missing Pattern Tools None Cutting Tools Fixtures Volume Capacity Cutting Direction Maintenance Over use Speed Dull Knife Standards Incentives Maintenance Space Time Available Stress Light Storage Schedule Schedule Environ. Substitute Standards Attitudes Temperature Wages Finish Specs Motivation Humidity Strength Composition Discipline Static Electricity Loose Trainers Spread Incorrect Shrinkage Tight Training None ENVIRONMENT MATERIALS PEOPLE Cost Wrong Size Cut Parts 7-31

32 Y Values Scatter Diagram Graph of one sample variable versus another May show cause and effect relationships May show strong correlation with a cause and effect relationship A correlation of +1 indicates a perfect positive relationship A correlation of 1 indicates a perfect negative relationship A correlation of 0 means no significant relationship X Values 7-32

33 Using a Scatter Diagram Vary over normal operating range Extrapolate with care don t go beyond the limits of the observed data Stratify or sort by classification, such as shift, to find interactions Beware of happenstance or hidden variable data in which there may appear to be a strong correlation but no valid reason for it 7-33

34 FMEA Definition A procedure by which each potential failure mode in a system is analyzed to determine the results of effects thereof on the system and to classify each potential failure mode according to its severity, the likelihood of it occurring, and the ability of the system to prevent it from occurring. 7-34

35 Background The failure mode and effects analysis (FMEA) is the most widely used analysis procedure in practice at the initial stages of system development. The FMEA is usually performed during the conceptual and initial design phases of the system in order to assure that all possible failure modes have been considered and that proper provisions have been made to eliminate all the potential failures. 7-35

36 History of FMEA Created by the aerospace industry in the 1960s. Ford began using FMEA in Incorporated by the Big Three in Automotive Industry Action Group and American Society for Quality Control copyright standards in

37 FMEA Flow Chart Define each step in Flow Determine probability of failure Determine detection rate of failure (control) List function Determine severity of failures Assign RPN Brainstorm potential failure modes Describe effects of the failures Take action to improve

38 Tracking Form Process FMEA Part/Process Suppliers Affected: Prepared by: Name: Manufacturing Model Year: FMEA Date: Reponsibility: Other Areas: Release Date: Key ProductionDate: Process Purpose Potential Potential Severity Class Potential Occur Current Detect RPN Recom Respon Actions Failure Effects Cause Controls Actions Mode 7-38

39 Additional RCA Tools and Techniques 7-39

40 TRIZ - Inventive Problem Solving The theory of inventive problem solving is based upon extensive research Scientific approach to new into real inventions. The research focused on the most significant of those solutions to engineering inventions - where the solution to the problem was not entirely obvious problems. and required no trade-offs. The results of which revealed that inventors worldwide sub-consciously applied a common technique - TRIZ brings together these techniques and combines them with very practical methods. Brainstorming (Osborne) Brainstorming - Catalogue Techniques Card / Post-it Systems This is a classic tool recognised by many, but it is not that successful at generating new ideas. As a method it is not efficient at generating new ideas - Life is just too short! Limited to smaller groups - can create problems with group dynamics. Participants Use pictorial matter (Catalogues, photos, etc.) as triggers. More structure than the classic - slightly more efficient as well. Generating new associations. Competitive analysis, new features. Participants Use slips to write ideas down - requires little management Idea generation for large intervention or leadership skills - It can be used successfully on large groups groups. A variation of this technique is 'pass it on' where participants pass on a single card adding ideas to the list. Brain writing - Similar to classic brainstorming - without the disadvantages. More efficient Ideal for new teams. Trigger / Cascade at generating new ideas. Participants use post-it pads to provide triggers for discussion. Knowledge Trees Structured brainstorming and reference technique for generation of new products. Highly effective when used by cross functional teams. Can be applied to virtually all aspects in the product design phase. The method was developed by IPM and is used on a regular basis. Parametric Analysis Parameter based analysis - Quantitative, Qualitative, Categorical. An existing (or competitor) product is used as a benchmark with particular attention being paid to specific parameters. It is then indicated how these parameters would have to be different to enhance satisfaction. Generating specifications. Sharing product knowledge and general understanding. Developing an existing product or product portfolio. Semantic Processes - Random Matching Semantic Processes - Idea Search Matrix Random word-to-word to trigger new associations Checklists of questions to trigger new thoughts and ideas General purpose tool General purpose tool 7-40

41 Excursion Technique Problem Abstraction - Why?Why?... Ideas Book Orthographic Analysis SCAMPER - Stretch Matrix Analogies Evaluation - PIPS Clichés and Proverbs Using words and situations to lead away from the problem and reality. Switching back when a new idea or association is seen. Often closes on one idea Problem Abstraction or Semantic Processes (redefinition) attempts to reduce problems to their most basic level - problem goals and boundaries are then set. The procedure then follows a series of Why? questions followed by a subsequent Alternative? Good Team exercise. General purpose tool Developing existing portfolio. Identifying market opportunities for new products. Simple technique but can reap good results - Ideas are entered Good when no time limit into a dedicated book from anyone who wishes (and at any time) - is present. Ongoing a relaxed approach to new ideas and suggestions. Can fall quickly suggestions. into disrepute if not part of an evaluations procedure. Orthographic analysis is a way of arranging several attributes of a Portfolio enhancement. problem in a graphical representation of corresponding Specific solutions to dimensions. A general purpose version of orthographic analysis known market takes a product and represents its Material, Manufacturing requirements. Processes and its Market along three orthographic axes. Substitute, Combine, Adapt, Magnify ( or Minify), Put to other uses, Eliminate, Re-arrange (or Reverse) - Together they make up a checklist of possible product modifications. A particular form of thinking or reasoning in which the properties of one object are thought of in terms of a second object which is different but does have elements in common with the former. Ideas may come from nature or other similar products. Product improvements and enhancements. New product features. Phases of Integrated Problem Solving - Is a numerical scoring tool Products and Processes that divides the problem (or opportunity) and processes into individual stages and evaluates individually. A technique to jog the mind out of conventional thinking (out of a General Use rut). Armed with a list of common Clichés and Proverbs ask how each one may apply or be applied to the subject or problem. 7-41

42 QFD : Quality Function Deployment Delphi Technique Brainstorming - Catalogue Techniques Card / Post-it Systems Market Needs Research Quality Function Deployment is a customer oriented approach to product development and innovation. It is a powerful tool for use by product managers and development teams. The methodology takes the design team through the concept, creation and realization phases of a new product with absolute focus. QFD also defines what the end user is really looking for in the way of features and benefits. The Delphi Technique pulls ideas from participants by means of a highly structured series of questionnaires gradually honing into problems or opportunities. Participants are chosen for their knowledge in their particular field. This technique is good for groups of participants who do not normally meet. The success or failure of this technique is only as good as the chosen participants. Participants Use pictorial matter (Catalogues, photos, etc.) as triggers. More structure than the classic - slightly more efficient as well. Participants Use slips to write ideas down - requires little management intervention or leadership skills - It can be used successfully on large groups. A variation of this technique is 'pass it on' where participants pass on a single card adding ideas to the list. Market Needs Research is a technique for finding out what the Customer requires (and needs) from a product. It determines whether Users perceive a need which is not currently satisfied by existing products. Similar to elements of the QFD process it is essential to have direct access to the end user and to understand user requirements. The process defines subsequent questions that need to be handled by traditional research methods (Quantitative and or Qualitative). Structured Product Specifications. Taking the 'Voice of the Customer' through all relevant areas of the Company. Problem solving, Product definition. Competitive analysis, new features. Idea generation for large groups New product specifications 7-42

43 Opportunity Specification A concise specification document describing the market need for a proposed new product. It is a good tool for screening new ideas (products) against the companys' capabilities. It describes the business opportunity of the proposed product in terms of core benefits. It also justifies the business opportunity in terms of commercial viability. Concise business justification, market opportunities, product identification Knowledge Trees Structured brainstorming and reference technique for generation of new products. Highly effective when used by cross functional teams. Can be applied to virtually all aspects in the product design phase. The method was developed by IPM and is used on a regular basis. Visual Mapping Series of matrices position product features and attributes in a visual way - Simple but powerful technique to share new product features with a multi disciplinary team Generating specifications. Sharing product knowledge and general understanding. Product definition - Aids in the communication between Development, Marketing, Industrial design. Product Function Analysis or (FAST) Function Analysis Systematic Technique is a method of systematically analysing the functions performed by a product. Once again intimate knowledge of the customers needs and wants with regards to product features and functions. A function tree answers the questions of How and Why functions are required. Good for analysing both new and existing products, the results of which being used in methodologies like QFD, VAVE, FMEA etc. FMEA Failure Mode Effect Analysis - Highlights the problem areas (safety related) of a design - Severity and Probability analysis. VAVE Value Analysis Value Engineered - Primarily an engineering / manufacturing tool to optimise design features in the most cost effective way Screening for potential problems (safety or reliability related) with new products. Optimised cost effective design prior to manufacture. 7-43

44 The 6s Process Define Measure and Analyze No Improve, Implement and Control Key Process Identified Data Collection Strategy Causes Identified? YES Propose Improvement Plan ID Customer Expectations Histogram No Implement Plan Process Flow Analysis Scatter Diagram Run Chart Control Chart Objectives Met? Collect & Analyze Data Root Cause Analysis (Cause & Effect, Pareto) Baseline Measures YES Compare with Previous Results Document & Standardize Monitor 7-44

45 Six Sigma Green Belt Analysis Process Determine what to measure, how to measure, and sampling scheme. Measure Construct Histogram Finish Improve the Process no yes Is it the expected shape? yes Is the data time dependent? yes Draw Control Chart(s) Capable? no no Identify Special Cause(s) Address Special Causes Significant Change? yes no In Control? no Identify Special Cause(s) Address Special Causes yes Evaluate Capability no Significant? yes 7-45