St. Clair College Lecture Notes Quality Control (MET505) Fall 2024 PDF

Lecture Note #1 Quality Control (MET505) Dr. Majed Etemadi Fall 2024 1 Chapter 1 INTRODUCTION TO QUALITY IMPROVEMENT 2 Objectives Upon completion of this section, you are expected to be able to define quality, quality co...

Lecture Note #1 Quality Control (MET505) Dr. Majed Etemadi Fall 2024 1 Chapter 1 INTRODUCTION TO QUALITY IMPROVEMENT 2 Objectives Upon completion of this section, you are expected to be able to define quality, quality control, quality improvement, statistical quality control, quality assurance, and process; be able to describe FMEA, QFD, ISO9000, ISO14000, Benchmarking, TPM, Quality by Design, Products Liability, and IT. 3 Think about the quality, how you can define it? pollev.com/majedetemadi701 4 Definitions Quality Ratio of the perceptions of performance to expectation. The American Society for Quality (ASQ) defines quality as a subjective term for which each person or sector has its own definition. In technical usage: The characteristics of a product or service that bear on its ability to satisfy stated or implied needs A product or service that is free of deficiencies 5 A more definitive definition of quality is given in ISO 9000. It is defined there as the degree to which a set of inherent characteristics fulfills requirements. Degree means that quality Inherent is defined as can be used with adjectives existing in something, such as poor, good, and especially as a permanent excellent. characteristic is a need or expectation that Qualitative or Quantitative is stated; generally implies by the organization, customers 6  IATF 16949. The global automotive industry standard for quality management systems. The automotive industry generally expects parts to be manufactured, assembled and tested in IATF 16949-qualified facilities 5 Core Tools in IATF: APQP PPAP SPC MSA FMEA 7  Quality QM has four main components: quality planning, quality management assurance, quality control and quality improvement. Quality management, uses quality assurance and quality control of processes to achieve more consistent quality. Quality Assurance Quality assurance is all the planned or systematic actions necessary to provide adequate confidence that Quality Improvement a product or service will satisfy given requirements for quality Quality improvement is the use of tools and techniques to continually make the product or service better and better. Quality Control Quality control is the use of techniques and activities to achieve and sustain the quality of a product or service. 8 Quality improvement is not the responsibility of any one person or functional area; it is everyone’s job. There are many improvement tools to assist the organization and individuals to improve their product or service. Tools covered briefly in this chapter are: FMEA, QFD, ISO 9000, ISO 14000, Benchmarking, TPM, Quality by Design, Products Liability, IT I will not go through all these tools ( you need to read from chapter 1 of book ) 9 FMEA Failure Mode and Effects Analysis 11 Failure Mode and Effects Analysis (FMEA) An analytical methodology used to ensure that potential problems have been considered and addressed throughout the product and process development process Part of this is the assessment of risk Meant to be a “before-the-event” action –this achieves value as actions from FMEA can reduce/ eliminate a change before it becomes difficult and expensive 12 Design and Process FMEA DFMEA Design Failure Mode and Effects Analysis Focus on part FUNCTION FMEA Focus on manufacturing steps or PROCESS Living document Initiated before or at feasibility stage, prior to tooling Considers all manufacturing operations PFMEA Process Failure Mode and Effects Analysis 13 Development of PFMEA To be developed by cross functional team, often led by the responsible engineer To ensure continuity, this should be the same team producing the DFMEA, PFMEA, Process Flow Diagram and Control Plan Team should assume the product as designed will meet design intent 14 Process Flow Diagram The Process flow diagram is the primary input The PFMEA will be consistent with the Process Flow Diagram 15 Control Plan The PFMEA will be consistent with the Control Plan The control plan is constructed at the end of the PFMEA 16 PFMEA 17 PFMEA A – Alphanumeric string to identify document B –Name/Number of component of process being analyzed C – OEM, organization and department that is responsible for process design D – Intended model/ program that will be affected by process analyzed E – Initial PFMEA due date, should not exceed scheduled start of production F – Date original was completed + revision date G – Team members responsible for development of PFMEA H – Name/ contact information (including company) of the team leader responsible 18 PFMEA 19 PFMEA a1 – Consistent number with control plan and process flow diagram a2 – Inputs to process specified to meet design intent, or customer requirement b – What can potentially go wrong c – What effects will happen if failure did occur e – May be used to highlight high priority failure modes 20  In-class activity Function : Attach a seat cushion to track using a torque gun 21 Example 22 PFMEA 23 PFMEA f – How failure can happen, in terms of things that can be corrected / controlled h – 1) Prevention: process to prevent the cause of failure mode, or reduce its rate h - 2) Detection: process to detect the cause of failure mode, or counter measures k – Intent is to decrease ranking in order of severity, occurrence, detection l – Name of person/ organization responsible for completing action h-1 h-2 24  In-class activity Complete the second part using the same example 25 Example 26 PFMEA 27 PFMEA The following are relative rankings, the team should agree on evaluation criteria Severity (S) – value associate with most serious effect for given failure mode Occurrence (O) – likelihood that a specific cause of failure will occur Detection (D) – rank associated with best detection control listed Risk Priority Number (RPN) – an approach for action prioritization RPN = Severity x Occurrence x Detection 28 An example of Severity criteria and rank 29 An Example of Occurrence Criteria and Rank 30 An Example of Detection Criteria and Rank 31 PFMEA 32 PFMEA Identifies results of any completed actions with their effects on Severity, Occurrence, Detection and RPN m – What action will be taken n – Updated values from complete action 33 Review FMEA 34 35 What and Why Control Plan What? A Control Plan: a description of the systems for controlling parts and processes, so to minimize variation Why? To decrease waste and increase quality Focus resources on quality which is important to customer A living document that identifies and communicates changes in product and process characteristics 36 Control Plan 37  Control Plan Header 1 7 10 11 2 8 12 3 4 9 13 5 6 14 Supplier Internal Customer What stage we are at. 5 information 9 Approval 13 Quality 1 Each stage has more detail approval 6 Supplier plant 14 code 10 Original date Customer 2 Job # Other Who is responsible approval 7 for control plan 3 Part # 11 Date of last revision 4 Part description 8 Team responsible 12 Date customer engineers since last revision approved 38 Control Plan 39 Control Plan 15 Often referenced from Process Flow Chart 15 17 19 20 21 16 18 16 All the steps from Process Flow Diagram 17 Equipment that will be used for every operation 18 Cross reference # to all applicable documents Distinguishin g feature for which data 19 Features/ properties – Primary engineering will be information collected 20 Often referenced from Process Flow Chart 21 Often blank. For any classification by the customer 40 Control Plan 41  Control Plan 22 23 24 25 22 What we are 24 How much and how often The corrective actions to looking for we will measure 26 take to avoid operating out of control and producing 23 How we will be 25 Specifications gathered from non-conforming parts measuring various engineering documents 42 Other Tools 43 Quality Function Deployment (QFD) Identifies and sets priorities for process improvement. Multifunction team uses ‘voice of the customer’ to achieve results throughout the organization. It reduces start-up costs and design changes that lead to increased customer satisfaction. 44 ISO 9000 (QMS) ISO Stands for International Organization for Standards. QMS stands for Quality Management System. The standard, recognized by over 100 countries, is divided into three parts. Fundaments and vocabulary, Requirements Continual improvement Management Responsibility Resource Management Product Realization Measurement, Analysis, and Improvement Improvement guidance. 45 Benchmarking Benchmarking was developed by Xerox in 1979. The idea is to find another company that is doing a particular process better than your company, and then, using that information to improve the process. Constant testing of industry’s best practices. 46 Total Productive Maintenance Total Productive Maintenance (TPM)is a technique that utilizes the entire work force to obtain the optimum use of equipment. The technical skills in TPM are: daily equipment checking machine inspection fine-tuning machinery Lubrication trouble-shooting, and repair. 47 Chapter 2 Lean Enterprise 48 Learning Objectives When you complete this chapter, you should: Know the definitions of value added and non-value added activities. Be able to describe the lean fundamentals. Be able to construct a value stream map. Understand how to implement lean. Be able to list five benefits to lean. 49 Path to Lean Theory Waste is Deadly Application 1- Define Value 2- Identify Value Stream 3- Make it flow 4- Let customer pull 5- Pursue perfection Focus Flow Focused Assumptions Non-value added steps exist Results Reduce Cycle time 50 Lean Fundamentals Types of waste Categories of waste Workplace organization Concept of flow Inventory control Visual management Kaizen Value stream 51 Do a Class Work You need to categorized the printed papers (box 1) based on different lean basics Then in the second box, there are some definitions, and you need to find them as well. We need three groups, the group with better performance (find the correct answer sooner) will get a bonus mark. 52 Value Stream Map (VSM) VSM graphically describes the sequence and movement of the activities. First develop map of current state. Next develop map of ideal state with only value-added activities. Difference provides opportunities for improvement. VMS in next slide and icons in following one. Theory of constraints (TOC)—one operation limits the throughput of the system at any one time. 53 Adapted from Cathy Kingery, Editor, The Lean Enterprise Memory Jogger. GOAL/QPC 2002 Sample Value Stream Map Value Stream Map Icon Designations 54 Implementing Lean Establish cross-function team. Train in lean fundamentals. Construct VSM for current and ideal. Analyze maps for best place to start. Train people in lean and simple SPC tools. Apply SS and Kaizen. Use Kaizen blitz where appropriate. Expand to other areas. Standardize the improvements. 55 Benefits to Lean Enterprise Tyco Flow Control: On time delivery—94%; Lead time—150 days to 56 days; Movement reduced by 68%; Machining capacity increased by 200%; Cycle time balanced; Incoming inspection reduced from 16 days to 1. Toyota success. Veridan Homes: Drafting time reduced by one hour; Inspection time by 50%; Cycle time 32 to 15 days 56 Review What is the difference between value added and no-value added activity? Name 4 of 7 categories of waste. What is the purpose of the value stream map. 57 Session 3 Dr. Majed Etemadi Fall 2021 58 Chapter 3 Six Sigma 59 Learning Objectives When you have completed this part you should be able to: Understand the concept of six sigma statistics. Describe DMAIC project methodology. Know the advantages of the methodology. 60 What is Six Sigma? Six Sigma is both a quality management philosophy and a methodology that focuses on reducing variation, measuring defects, and improving quality of products, processes and services. Sigma is the Greek word for the symbol, σ, which stands for the population standard deviation. 61 Statistical Aspect It is the best measure of variation. If we can reduce variation to the point that the specifications are at ±6σ, then 99.9999998% of the items are satisfactory. 62 Normal Distribution A: 68.27% of the population exists between –σ & +σ → [34.134% + 34.134%] B: 95.45% of the population exists between –2σ & +2σ → [68.27% +2*(13.59%)] C: 99.73% of the population exists between –3σ & +3σ → [95.45%+2*(2.14%)] D: Therefore, 0.27% of the population exist outside of the -/+3σ limits [100%-99.73%] 63 Cp and Cpk – Definitions USL = Upper specification limit It could be for a product or process It will be set by management or anyone has the authority to say what is the acceptable upper and LSL = Lower specification limit lower limits of the specification of the entity that we’re looking at UCL = Upper control limit LCL = Lower control limit DSW= Design specification width = USL – LSL NPR= Natural process range = UCL - LCL 64 Cp and CPK – Definitions (cont’d) σ = Sigma, the process population standard deviation s = Process sample standard deviation 𝑥Ӗ = Process average Z = Distance between the process average and either the upper or lower spec limit. Measured as the number of standard deviation 65 Cp and CPK – Definitions (cont’d) Cp = Process capability. Estimates the extent of process capability if a process is centered, but without respect to the spec limits. Assumes the process output is approximately normally distributed 𝐷𝑒𝑠𝑖𝑔𝑛 𝑠𝑝𝑒𝑐𝑖𝑓𝑖𝑐𝑎𝑡𝑖𝑜𝑛 𝑤𝑖𝑑𝑡ℎ 𝐷𝑆𝑊 𝑈𝑆𝐿−𝐿𝑆𝐿 = = = 𝑁𝑎𝑡𝑢𝑟𝑎𝑙 𝑝𝑟𝑜𝑐𝑒𝑠𝑠 𝑟𝑎𝑛𝑔𝑒 𝑁𝑃𝑅 𝑈𝐶𝐿−𝐿𝐶𝐿 Expressed in terms of σ Lower that one, you got defects built into With the objective that 𝐶𝑝 ≥ 1.00 your process or into the products that are being produced. 66 Design Specification Width (DSW) = Xσ Natural Specification Range (NPR) = 6σ 67 Cp and CPK – Definitions (cont’d) CPK = Mean-sensitive process capability index. This index is an adjustment of Cp to account for the effect of a non-centered distribution. CPK = Quantitatively-stated location of natural process range (NPR) with respect to the boundaries of the design spec width (DSW) When process mean is centered on nominal/target spec, CPK = CP. Otherwise 𝐶𝑃𝐾 ≤ 𝐶𝑃. Assumes process output is approximately normally distributed 68 Cp and CPK – Definitions (cont’d) 𝑍𝑚𝑖𝑛𝑖𝑚𝑢𝑚 𝐶𝑃𝐾 = 3 𝐶𝑃𝐾 = 𝑀𝑖𝑛𝑖𝑚𝑢𝑚 𝑍𝑈𝑝𝑝𝑒𝑟 , 𝑍𝐿𝑜𝑤𝑒𝑟 𝑈𝑆𝐿−𝑥Ӗ 𝑥−𝐿𝑆𝐿 Ӗ 𝐶𝑃𝐾 = 𝑀𝑖𝑛𝑖𝑚𝑢𝑚( , ) ≥ 1.00 3𝜎 3𝜎 69 Example Given Nominal = 100 USL = 100+6=106 Design specification = 100 +/- 6 LSL=100-6=94 Let 𝑥Ӗ = 100 𝑎𝑛𝑑 𝜎 = 2 𝑓𝑜𝑟 𝑡ℎ𝑒 𝑝𝑢𝑟𝑝𝑜𝑠𝑒 𝑜𝑓 𝑑𝑒𝑚𝑜𝑛𝑠𝑡𝑟𝑎𝑡𝑖𝑜𝑛 𝑈𝑆𝐿−𝐿𝑆𝐿 106−94 𝐶𝑃 = = = 1.00 6𝜎 2×6 70 Example Calculating 𝐶𝑃𝐾 𝑈𝑆𝐿−𝑥Ӗ 𝑥−𝐿𝑆𝐿 Ӗ 106−100 100−94 𝐶𝑃𝐾 = 𝑀𝑖𝑛𝑖𝑚𝑢𝑚 , = 𝑚𝑖𝑛𝑖𝑚𝑢𝑚 , = 3𝜎 3𝜎 6 6 𝑚𝑖𝑛𝑖𝑚𝑢𝑚 1,1 = 1.00 71 Example – Conclusion As 𝐶𝑃𝐾 = 𝐶𝑝 , it can be said that the process average is centered on the nominal specification. Since 𝐶𝑝 ≥ 1.00, we conclude the process is capable of producing work within the specs Since 𝐶𝑝𝑘 ≥ 1.00, we conclude the work produced by the example process fits within the specs Even if 𝐶𝑝 ≥ 1.00, remember 𝐶𝑝𝑘 ≥ 1.00 to be certain about a capable process that producing acceptable work. 72  𝐶𝑃 =1.00 (σ=2) Cp and CPK – Interrelationships 𝐶𝑃 =2.00 (σ=2) 6σ Capability and Cp/Cpk Relationship 74 Process Measures When a process is in statistical control, i.e., it is both predictable and generation data that forms a normal distribution; then the following interrelationships between the various process measures are valid equivalencies. 75 Process Measures (cont’d) Reproducing Table 3-2 76 Six Sigma Equivalencies 6 Sigma 3.4 ppm Grade Sigma 5 Sigma A 233 ppm Uncommon Science 4 Sigma 6,200 ppm B Common Science 3 Sigma Good 66,803 ppm C Common Sense D Ad hoc Start up F 2 Sigma 308,733 ppm DPMO – Defect Rate 77 Lean vs. Six Sigma Lean Tends to be used for shorter, less complex problems Often time driven Focus is on eliminating wasteful steps and practices. Six Sigma Bigger and more analytical approach Often quality driven Tends to have a statistical approach Focus on optimizing the important steps → reducing defects 78 What is the muddiest point ? 79 Improvement Methodology – The DMAIC Define – describe the problem quantifiably and the underlying process to determine how performance will be measured. Measure – use measures or metrics to understand performance and improvement opportunity. Analyze – identify the true root cause(s) of underlying problem. Improve – identity and test the best improvements that address the root cause. Control – identify sustainment strategies that ensure process performance maintains the improved state. 80