Date post: | 22-Dec-2015 |
Category: |
Documents |
View: | 215 times |
Download: | 1 times |
EngineeringManagement Six Sigma Quality
Engineering
Week 4
Chapters 5 (Measure Phase)
Chapter 5 Outline
Process Map Cause & Effect Matrix Fishbone Diagram Fayetteville Paint Line
Lean & Kaizen Reproducibility & Repeatability (Gage R&R) Capability Analysis Components of Variation Studies FMEA
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
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
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
Detailed Process Map Example
PICKLE RINSE
(Y's)Acid freeDebris removed
(Y's)Surface cleanliness- Removel of sand- Removal of rust- 'Defect free'
SHOTBLAST
(Y's)Surface cleanliness (dust / rust free)Surface roughness
HANG ON PENDANTS
STAND
UNCOATED FITTINGS
(x's)C TimeC Shot size / mix of sizesN HumidityS Type / Material / Original size of gritN Effectiveness of seperatorN Product geometryN Condition of machineN Dust arrestor conditionS Amount of work being shotblastC Time between pickle and shotblastN Operator
(x's)C TimeN Product geometryN OperatorS Rocked / Not rockedS Method of packing
(x's)C Make up of mix, Concentration and % of Hydrochloric Acid, Hydrofluoric Acid, Activol, WaterC Pickling timeS Age of mix / SGN Quality of work / containerN Containers / tankN Product geometryS Packing methodN OperatorS Shotblast prior to pickling
LYE BATH
(Y's)Uniformity of fluxNo excess flux (removed by Dry ing Oven)
DRYING TUNNEL
(Y's)Dry castingsWarm castings
DIP IN ZINC BATH / BUMP
(Y's)Coating Quality- Thickness of z inc / z inc alloy layers- Uniformity of coverage- Total coverage- Appearance- Roughness / tex ture- Composition of coating
WATER SPRAY KNOCK OFF
RUMBLE
(Y's)AppearanceSmooth Finish
(Y's)Zinc : Zinc Alloy thicknessAppearance (brightness)Removal of ash (c leanliness)Fitting temperature COATED
FITTINGS
(x 's)C Speed of chain / time in bathC Temperature of lye bathC Make up of lye bathS Cleanliness of lye bathN Geometry of partsS Pendant sty le / orientation of workS Amount per pendantS Weight of product per minute put through bath (Heat removal + heat pickup)S Time from shotblastN Humidity
(x 's)C Speed of chainS Temperature of tunnelN Geometry / Mass of fittingsN HumidityS Air velocity
(x 's)S Quality of supplier / materialsC Temperature of z incS Level of drossS Level of leadN Geometry / mass of fittingsN Operator (Skimming surface / agitation of pendants)S Quality of pendantsN Specifiacation (BS, ISO, EN)S Rate of withdrawalS Fluidity of z incN Power of bumper unit
(x 's)S Water volumeN Water temperatureC Speed of chainN Mass / Geometry of fittings (Rate of cooling)
(x 's)C TimeC Number of fittings per loadN Geometry of fittingsS Condition of rumbling barrel
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
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
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
Inputs (x’s)Rotation speedTraverse speedTool typeTool sharpnessShaft materialShaft lengthMaterial removal per cutPart cleanlinessCoolant flowOperatorMaterial variationAmbient temperatureCoolant age
Outputs (Y’s)DiameterTaperSurface finish
CCCCCCCSCNNNS
Suggested Elements
Process StepCycle Time
DPUInputs(x’s)
Outputs(Y’s)
Too little detail will not expose
the problem. Too much detail will
hide the problem.
BEFORE40 NVA STEPS
NOTE: FROM THE CUSTOMER’S VIEWPOINT ALL OF ORDER ENTRY IS NON-VALUE ADDED
Order Entry Process MapAs-Is
AFTER11 NVA STEPS
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
Order Entry Process MapNew
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
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
BEFORE KAIZEN:Area: 4640 sq ftOperator Travel: 3696 ftProduct Travel: 1115 ft
xxx x
x xxx
x
Cause & Effect
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 Analysis
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
Effect
• The problem or quality characteristic
• The effect is the outcome of the factors that affect it
Effect
Causes
All the factors that could affect the problem or the quality characteristic
Five Major Categories
• Materials
• Methods
• People
• Machines
• Environment
Effect
PeopleMethodsMaterial
Machine Environment
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
Fayetteville Paint Line Cause and Effect
Benefit• Gain new knowledge and perspectives by sharing
ideas with others• Helps us understand our processes• Provides a basis for action
• Whenever a problem is discovered, using C&E analysis forces us to take a proactive stance by seeking out causes
Fayetteville Paint Line
Instructions
This table provides the initial input to the FMEA and experimentation. When each of the output variables (requirements) are not correct, that represents potential "EFFECTS". When each input variable is not correct, that represents "Failure Modes".
1. List the process output variables 2. Rate each output on a 1-to-10 scale to importance to the customer3. List process input variables (from the process map)4. Rate each input's relationship to each output variable using a 0, 1, 3, 9 scale 5. Select the high ranking input variables to start the FMEA process; Determine how each selected input variable can "go wrong" and place that in the Failure Mode column of the FMEA.
This table provides the initial input to the FMEA and experimentation. When each of the output variables (requirements) are not correct, that represents potential "EFFECTS". When each input variable is not correct, that represents "Failure Modes".
1. List the process output variables 2. Rate each output on a 1-to-10 scale to importance to the customer3. List process input variables (from the process map)4. Rate each input's relationship to each output variable using a 0, 1, 3, 9 scale 5. Select the high ranking input variables to start the FMEA process; Determine how each selected input variable can "go wrong" and place that in the Failure Mode column of the FMEA.
Rating of Importance to
Customer
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Total
Process Step Process Input
1 02 03 04 05 06 07 08 09 0
10 011 012 013 014 015 016 017 018 019 020 0
0
Total 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Lower Spec
Target
Upper Spec
1
2
3
4
5&6
A Kaizen Blitz is a cross functional multi-level team of 5 to 10 members working intensely for 10 to 14 hours a day, to rapidly develop, test and refine solutions to problems and leave a new solution in place in just a few days. They don’t plan, they don’t propose, they do.
This focus on immediate change is what sets Kaizen activity apart from other improvement tools.
What is a Kaizen Blitz?
A Kaizen Blitz, used in conjunction with the Toyota Production System (TPS) and current Lean
Manufacturing principles, can serve as a catalyst for the initial implementation of a plant wide Lean
Manufacturing initiative.
HOW ?
Depending on the individual event, many of the Lean elements previously mentioned are
tackled during a Kaizen Blitz event.
How do you get started?
12 3
4
5
6
789
10
11
12
Our Way of Life
Recognize the Needfor Change
Schedule the Event
Select System / Process to Optimize
Develop the Objectives
Process Owner: Review& Explains Objectives
Learning the Tools• 5S, Process Flow• TAKT / Cycle Time
Capture the Details• Data Gathering• Detail Analysis
Set Goals,Make a
Plan
Make the Change
Process Owner:Accepts Change
Formalize the Change
Cycle of an Event
Step One
Choose Your Project Well• High Probability For Success• Good Visibility• Short In Duration• Requires Several “Lean Tools”• Is Measurable
Step Two
Choose Your Team Well• Open Minded And Enthusiastic• Select People Who Work With The Product
• Operators
• Maintenance People
• Supervisors
• ME/IE
• Planners
Step Three
Train! Train! Train!• Overview Of Six Sigma • Continuous Improvement• Single Piece Build (Use The “Stockless Production” Video Made
By Hewlett Packard• Use Your Black Belts
Step Four
Calculate Takt Time• This Is The Customers Drum Beat• Takt Time = Units Purchased Per Day Divided Into Actual Time
Available In A Shift• Example: 27,000 Seconds / 20 Units = 1350 Seconds Per Unit Or
(1) Unit Every 22.5 Minutes
The time (pace) required to produce aproduct based on customer demand.
Often expressed as: TAKT TIME = Time AvailableCustomer Demand
Example: Elevator Manufacturer
-Customer Demand: 50 Hydraulic Elevators / Week-Daily Demand: 10 Hydraulic Elevators-Time Available: 435 Minutes / Day (480 min less cleanup, breaks)
435 / 10 = 43.5 Minutes per elevator = TAKT TIME
This pace must be maintained in order to satisfy customer demand!
Takt Time
The time for an operatorto do a prescribed taskand return to his/her
original stance.
Cycle Time
The amount of time it takesto convert raw materials into
finished goods (External Customer)or to move goods from one part
of the process to another(Internal Customer)
Lead Time
Task1
Task2
Task3
Task4
Task5
Lead Time
MOVE WAIT SET-UP RUN
Cycle Time
Cycle Time vs. Lead Time
Lead Time
PROCESS
WIP
>TAKT Time is a rate of demand>Lead Time is how long the whole process takes>They are NOT related!
1 Unit / MinuteTAKT Time
Can a process have a 1 hour TAKT Time and a 6 month Lead Time?
Takt Time vs. Lead Time
Step Five
Study The Project• Team Meetings To Discuss The Project • Set Objectives
• 25% Improvement In Through Put
• 50% Reduction In Floor Space
• 65% Reduction In Inventory
• Meeting The Takt Time
• Establish The Metrics
(Process oriented layout with Lot Size = 5)Processing Time = 1 Minute / Unit
Process Flow
TIME ELAPSED (MINUTES)0 5 10 15 20
NOTE: Typically, the distances between process is long in a process oriented layout, making difficult to transfer units one-by-one.
Manufacturing Lead Time
Batch vs. One-Piece Flow
(Process oriented layout with Lot Size = 1)Processing Time = 1 Minute / Unit
Process Flow
TIME ELAPSED (MINUTES)0 1 2 3 4
Manufacturing Lead Time
Add the Balance of Units (4 x
1’/Unit)8
Batch vs. One-Piece Flow
Questions? Comments?