six sigma quality engineering l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Six Sigma Quality Engineering PowerPoint Presentation
Download Presentation
Six Sigma Quality Engineering

Loading in 2 Seconds...

play fullscreen
1 / 45

Six Sigma Quality Engineering - PowerPoint PPT Presentation


  • 237 Views
  • Uploaded on

Six Sigma Quality Engineering. Week 4 Measure Phase. Chapter 5 Outline. Process Map/Spaghetti Diagram Cause & Effect Fishbone Diagram Cause & Effect Matrix Reproducibility & Repeatability (Gage R&R) Capability Analysis Components of Variation Studies FMEA. Process Map/Spaghetti Diagram.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Six Sigma Quality Engineering' - johana


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
six sigma quality engineering

Six Sigma Quality Engineering

Week 4

Measure Phase

chapter 5 outline
Chapter 5 Outline
  • Process Map/Spaghetti Diagram
  • Cause & Effect Fishbone Diagram
  • Cause & Effect Matrix
  • Reproducibility & Repeatability (Gage R&R)
  • Capability Analysis
  • Components of Variation Studies
  • FMEA
what is a process map
What is a Process Map?
  • A process map is a graphical representation of the flow of a process
  • A detailed process map includes information that can be used to improve the process, such as:
    • Process Times
    • Quality
    • Costs
    • Inputs
    • Outputs
types of process map
Types of Process Map
  • Basic process map
  • Detailed process map
  • Work-flow (spaghetti diagrams)
  • Top-down flowchart
  • Deployment flowchart
  • Opportunity flowchart
  • Current State / Future state maps
uses of a process map
Uses of a Process Map
  • Identify areas for focus of improvement efforts
  • Identify and eliminate non-value added steps
  • Combine operations
  • Assist root cause analysis
  • Baseline for failure mode and effect analysis (FMEA)
  • Identify potential controllable parameters for designed experiments
  • Determine needed data collection points
  • Eliminate unnecessary data collection steps
process maps
Process Maps
  • Should include
    • Major activities and tasks
    • Sub-processes
    • Process boundaries
    • Inputs
    • Outputs
  • Documents reality, not how you think the process is supposed to be completed
  • Should identify opportunities for improvement
steps for process mapping
Steps for Process Mapping
  • Scope the process
    • Identify the start and end points of the process of interest
  • Document the top level process steps
    • Create a flow chart
  • Identify the inputs and outputs
    • What are the results of doing each process step? (Y’s)
    • What impacts the quality of each Y? (x’s)
  • Characterise the inputs
characterising inputs
Characterising Inputs
  • Inputs can be classified as one of three types
  • Controllable (C)
    • Things you can adjust or control during the process
      • Speeds, feeds, temperatures, pressures….
  • Standard Operating Procedures (S)
    • Things you always do (in procedures or common sense things)
      • Cleaning, safety….
  • Noise (N)
    • Things you cannot control or don not want to control(too expensive or difficult)
      • Ambient temperature, humidity, operator...
example

Machining a shaft

on a lathe

Example

Outputs (Y’s)

Diameter

Taper

Surface finish

C

C

C

C

C

C

C

S

C

N

N

N

S

Inputs (x’s)

Rotation speed

Traverse speed

Tool type

Tool sharpness

Shaft material

Shaft length

Material removal per cut

Part cleanliness

Coolant flow

Operator

Material variation

Ambient temperature

Coolant age

order entry process map as is
Order Entry Process MapAs-Is

BEFORE

40 NVA STEPS

NOTE: FROM THE CUSTOMER’S VIEWPOINT ALL OF ORDER ENTRY IS NON-VALUE ADDED

order entry process map new
Order Entry Process MapNew

REMEMBER: FROM THE CUSTOMER’S VIEWPOINT ALL OF ORDER ENTRY IS NON-VALUE ADDED

We eliminated the steps that were NVA and UNNECESSARY (WASTE)

BEFORE

40 NVA STEPS

AFTER

11 NVA STEPS

work flow or spaghetti diagram
Work-flow or Spaghetti Diagram
  • A work flow diagram is a picture of the movements of people, materials, documents, or information in a process.
  • Start by tracing these movements onto a floor plan or map of the work space.
  • The purpose of the work-flow diagram is to illustrate the inefficiency in a clear picture.
  • How can you make the map look simpler? What lines can you eliminate?
56 frame small motor assy fabrication before
56 Frame (Small Motor) Assy & Fabrication - Before

x

x

x

x

BEFORE KAIZEN:

Area: 4640 sq ft

Operator Travel: 3696 ft

Product Travel: 1115 ft

x

x

x

x

x

cause effect fishbone diagram
Cause & Effect Fishbone Diagram
  • Objectives
    • To understand the benefits of Cause & Effect Analysis
    • To understand how to construct a C & E Diagram
  • Analysis
    • A method a work group can use to identify the possible causes of a problem
    • A tool to identify the factors that contribute to a quality characteristic
uses of c e fishbone diagram
Uses of C & E Fishbone Diagram
  • Visual means for tracing a problem to its causes
  • Identifies all the possible causes of a problem and how they relate before deciding which ones to investigate
  • C & E analysis is used as a starting point for investigating a problem
fishbone diagram
Fishbone Diagram
  • Effect
    • The problem or quality characteristic
    • The effect is the outcome of the factors that affect it

Effect

fishbone diagram20
Fishbone Diagram

Causes

  • All the factors that could affect the problem or the quality characteristic
  • Five Major Categories
    • Materials
    • Methods
    • People
    • Machines
    • Environment
slide21

Machine

Environment

Effect

Material

Methods

People

the eight steps in cause and effect analysis
The Eight Steps in Cause and Effect Analysis
  • Define the Effect
  • Identify the Major Categories
  • Generate Ideas
  • Evaluate Ideas
  • Vote for the Most Likely Causes
  • Rank the Causes
  • Verify the Results
  • Recommend Solutions
slide24

2

1

5&6

3

4

reproducibility repeatability gage r r
Reproducibility & Repeatability (Gage R&R)

“Data is only as good as the system that measures it. If you can’t measure it, you can’t manage it.”

the science of measurement
The Science of Measurement

“I often say that when you measure what you are speaking about and express it in numbers, you know something about it.”

LORD KELVIN, 1891

He clearly stressed that little progress is possible in any field of investigation without the ability to measure. The progress of measurement is, in fact, the progress of science.

objectives
Objectives
  • Measurement Systems Analysis
  • Key Terminology
  • Variable Gauge R&R
    • A tool for estimating measurement system error
    • How to conduct a gauge R&R
    • Minitab Output
  • Gauge R & R Study Exercise
definitions
Definitions
  • Variable Data
    • Continuous measurements such as length, voltage, viscosity
  • Repeatability
    • Variation in measurements obtained with one gage when used several times by one appraiser.
  • Reproducibility
    • Variation in the average of the measurements made by different appraisers using the same measurement system.
what is gr r
What is GR&R?

Measurement Systems Analysis

How good is our measurement system?

2T = 2p + 2m

2T = Total Variance

2p = Process Variance

2m = Measurement Variance

GRRRRRRR!!!

variable gauge r r what s involved
Variable Gauge R&R - What’s Involved?

3 Appraisers

1 Gauge

10 Parts

how to set up a variable grr study
How to set up a Variable GRR Study
  • Preparation & Planning
  • 1 Gauge
  • 3 Operators (Appraisers)
  • 10 Parts
  • 3 Trials
  • Randomize the readings
  • Code the parts (blind study) if possible
  • 3 Ops x 10 parts x 3 trails = 90 Data Points
  • 4 Ops x 10 parts x 3 trails = 120 Data Points
minitab gage r r graphical output
Minitab Gage R&R Graphical Output

The number of distinct categories of parts that the process is currently able to distinguish (Must distinguish at least 5 types of parts)

acceptability criteria
Acceptability Criteria
  • R&R Indices
    •  10% Acceptable Measurement System
    • 10% - 30% May be acceptable based upon application, cost of measurement device, cost of repair, etc.
    •  30%Not acceptable. Measurement system needs improvement.
  • Number of Distinct Categories Index
    • 1 Unacceptable. One part cannot be distinguished form another.
    • 2 -4 Generally unacceptable
    •  5 Recommended

Module 0025

cpk cp
Cpk & Cp
  • Cpk incorporates information about both the process spread and the process mean, so it is a measure of how the process is actually performing.
  • Cp relates how the process is performing to how it should be performing. Cp does not consider the location of the process mean, so it tells you what capability your process could achieve if centered.
non normal distributions
Non-normal distributions
  • Use Capability Analysis (Nonnormal) to assess the capability of an in-control process when the data are from the nonnormal distribution. A capable process is able to produce products or services that meet specifications.
  • The process must be in control and follows a nonnormal distribution before you assess capability. If the process is not in control, then the capability estimates will be incorrect.
  • Nonnormal capability analysis consists of a capability histogram and a table of process capability statistics