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Lean Manufacturing - An Overview. Dr. Richard A. Wysk. rwysk@psu. edu
Lean Manufacturing - An Overview Dr. Richard A. Wysk Fall 2008 There are two parts to the Lean Manufacturing module. Part 1 focuses on a basic overview of Lean Principles, and describes “waste” in some detail. Part #2 deals more with the “flow” component of Lean. The background required for these modules is limited to “an understanding of manufacturing systems”. Two approaches can be taken for this presentation. If a more senior audience is the focus, senior undergraduates, graduate students or industry practitioners, then the focus of implementation roadblocks can be maintained. For a less experienced audience, principles concerning more common examples (like office work and McDonalds) will make a more interesting “case” for examples. There is a Case Study that is used to illustrate Waste Reduction and Value Stream Mapping principles.
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Broad Agenda Overview of Lean Manufacturing Case Study
Lean according to R. Wysk Set-up reduction and rapid response production systems Changing in order to change more quickly Case Study Lean at home in the kitchen Some models and discussions Learning/forgetting 6 sigma in rapid response systems
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Agenda Review brief history of manufacturing systems
Distinguish between mass, craft and lean manufacturing Introduce key Concepts of Lean Manufacturing Review the kinds of changes needed to be considered a lean manufacturer. The focus here is on the trends towards smaller lot sizes, more frequent change over and higher flexibility required today.
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Readings Chapter 18 of Computer Aided Manufacturing, Wang, H.P., Chang, T.C. and Wysk, R. A., 4th Edition (2008 expected) There is no good reference here. The web site is not operational at this time. Hopefully by August 2002, the introductory chapter will be available.
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Objectives To identify waste elements in a system
To apply value stream analysis to a complex engineering/manufacturing system To implement 3 M’s in a complex engineering environment To be able to identify and implement the 5Ss of lean
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Craft Manufacturing Late 1800’s
Car built on blocks in the barn as workers walked around the car. Built by craftsmen with pride Components hand-crafted, hand-fitted Good quality Very expensive Few produced
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Mass Manufacturing Assembly line - Henry Ford 1920s
Low skilled labor, simplistic jobs, no pride in work Interchangeable parts Lower quality Affordably priced for the average family Billions produced - identical Time & Motion studies - Fredrick Taylor Interchangeable parts - Eli Whitney
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Lean Manufacturing Cells or flexible assembly lines
Broader jobs, highly skilled workers, proud of product Interchangeable parts, even more variety Excellent quality mandatory Costs being decreased through process improvements. Global markets and competition.
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Definition of “Lean” Half the hours of human effort in the factory
Half the defects in the finished product One-third the hours of engineering effort Half the factory space for the same output A tenth or less of in-process inventories Term “lean” coined by John Krafcik, one of the research members on Jim Womack’s MIT team for the 5 year study. Materials Labor Equipment Energy Methods Products Source: The Machine that Changed the World Womack, Jones, Roos 1990
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Lean Manufacturing Product Shipment Customer Order Waste Time Customer
is a manufacturing philosophy which shortens the time line between the customer order and the product shipment by eliminating waste. Business as Usual Product Shipment Customer Order Waste Time Lean Manufacturing The sooner product ships, the sooner Cedar Works gets paid The faster material moves through the system Less money tied up in inventory in the system Customer Order Product Shipment Waste Time (Shorter)
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The Nature of Lean Mfg What Lean Mfg is not Characteristics Defined
JIT Kanban Six sigma Characteristics Fundamental change Resources Continuous improvement Defined “A system which exists for the production of goods or services, without wasting resources.”
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Introduction In 1926 Henry Ford wrote
“To standardize a method is to choose out of the many methods the best one, and use it. Standardization means nothing unless it means standardizing upward. Today’s standardization, instead of being a barricade against improvement, is the necessary foundation on which tomorrow’s improvement will be based. If you think of “standardization” as the best that you know today, but which is to be improved tomorrow - you get somewhere. But if you think of standards as confining, then progress stops.”
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Kaizen vs Reengineering
Creating an useable and meaningful standard is key to the success of any enterprise. Businesses usually utilize two different kinds of improvements. Those that suppose a revolution in the way of working. Those that suppose smaller benefits with less investment. Kaizen Final situation Initial situation time Reengineering productivity
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Kaizen vs Reengineering
The evolution consists of continuous improvements being made in both the product and process. A rapid and radical change (kaikaku) process is sometimes used as a precursor to kaizen activities. Carried out by the utilization of process reengineering or a major product redesign. Require large investments and are based on process automation. In the U.S., these radical activities are frequently called “kaizen blitzes”.
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Kaizen vs Reengineering
If the process is constantly being improved (continuous line), the innovation effort required to make a major change can be reduced (discontinuous line in the left). Otherwise, the process of reengineering can become very expensive (discontinuous line in the right). Kaizen Final situation Initial situation time Reengineering productivity
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What makes a manufacturing system lean? – the 3 M’s of lean
muda – waste mura - inconsistency muri - unreasonableness
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What makes a manufacturing system Lean?
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Definitions Systems Waste Recognition Efficiencies Muda 7 types
Truly lean
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“Anything that adds Cost
Waste “Anything that adds Cost to the product without adding Value” Who decides what is valuable? ---->>> Customer
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7 Types of Muda Excess (or early) production Delays
Transportation (to/from processes) Inventory Inspection Defects or correction Process inefficiencies and other non-value added movement (within processes)
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7 Forms of Waste Types of Waste CORRECTION MOTION WAITING PROCESSING
Repair or Rework Any wasted motion to pick up parts or stack parts. Also wasted walking Any non-work time waiting for tools, supplies, parts, etc.. Types of Waste PROCESSING OVERPRODUCTION Producing more than is needed before it is needed Doing more work than is necessary Discuss each Ask for examples of each type from different work areas at Cedar Works. Transition to Mercury Marine video. After video, tee up introduction of Cedar Works Production System and Lean Manufacturing. “So what do you think it will take for Cedar Works to steadily eliminate waste, or NVA from their operations?? Discussion INVENTORY CONVEYANCE Maintaining excess inventory of raw mat’ls, parts in process, or finished goods. Wasted effort to transport materials, parts, or finished goods into or out of storage, or between processes.
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Let’s use lean for something we know about – cooking for a party
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Excess /Over-production – As applied to fast food preparation
________________
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Waiting/Delays __________
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Transportation/Movement
_________
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Layout efficiency
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Inventory _________
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Inspection __________________ ______________
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Corrections and defects
____________
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Processing inefficiencies
__________________
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Processing inefficiencies
Automatics vs. manual
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Over-Processing inefficiencies
Automatics vs. manual Two people doing some thing that one could do Workplace layout Congestion Labeling
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Over-Processing inefficiencies
Material waste
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Manufacturing inefficiencies
Processes (value added) Inefficient process selection Inefficient process operation Too much direct labor Delays Schedules Blocking Congestion Quality Any defects Rework Set-up Setting up a machine instead of running it Accumulation of tooling and other processing needs
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Machining example CNC versus manual Tool changer
Pallet changer/bar feeder
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How do CAD/CAM systems work?
Developing NC code requires an understanding of: Part geometry Tooling Process plans Tolerances Fixturing Most CAD/CAM systems provide access to:
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Instructions can be generated for a generic NC machine
A set of tool paths and positions can be automatically generated These paths can be edited and modified These paths and instructions can then be “posted” to a specific machine
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The Design Process : Then and Now
Before CAD After CAD
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Exercise (3-5 minutes) Discuss how CAD/CAM helps in Lean Manufacturing? Elaborate on any one aspect. What advantages does CAD/CAM approach offer in NC Programming?
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CAD/CAM Support AutoCAD Pro Engineer Solidworks MasterCAM
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What do I need to begin MasterCAM?
Part geometry Draw or import Tooling Library or create Process plans Fixtures Define orientation and location
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$ Who wants what... Cash !! Value !! Customer Low Cost Your Company
High Quality Availability What we have here is a pretty fundamental relationship. Each party wants something; the customer and Cascade. The essential ingredients that make the whole thing go are: Value to the Customer Profit to Cascade These are the two fundamentals that MUST be there for a company to grow and thrive. If only one side of this flow takes place, the company will soon be out of business; if the customer does not receive adequate value if the company doesn’t make sufficient profit As for value to the customer, what determines if the customer is getting good value? Answer: Desired product and features at low cost. As for Cascade, what determines how much profit you make? Answer: Sales Price - Cost to produce Transition to next slide Your Company Profit Repeat Business Growth
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Elements of Lean Manufacturing
Waste reduction Continuous flow Customer pull 50, 25, 25 (80,10,10) Percent gains
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Benefits of Lean Manufacturing
% Waste reduction WIP Inventory Space Personnel Product lead times Travel Quality, costs, delivery
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Setting the Foundation
Evaluating your organization Management culture Manufacturing culture Lean Manufacturing Analysis Value stream (from customer prospective) Headcount WIP Inventory Capacity, new business, supply chain
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Tools of Lean Mfg/Production
Waste reduction Full involvement, training, learning Cellular mfg Flexible mfg Kaikaku (radical change) Kaizen (continuous improvement) & standard work 5S Jidoka (autonomation) Poka-yoke (visual signals) Shojinka (dynamic optimization of # of workers) Teien systems (worker suggestions) Six sigma
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Tools (cont.) Continuous Flow (10% - 25%) SMED (Shingo) Andon
Takt time Line balancing Nagara (smooth production flow)
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Tools (cont.) Customer pull (10%- 25%) Just-in-time Kanban
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Standardized Work Captures best practices Posted at the work station
Visual aid Reference document work sequence job layout time elements safety Developed with operators Basis for Continuous Improvement Show sample Standardized Work from Cedar Works Bring training manual
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Other Tools Visual Factory Error Proofing Quick Change-over
Total Productive Maintenance
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5S Programs Seiri (sort, necessary items)
Seiton (set-in-order, efficient placement) Seison (sweep, cleanliness) Seiketsu (standardize, cont. improvement) Shitsuke (sustain, discipline)
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Visual Factory “Ability to understand the status of a production area in 5 minutes or less by simple observation without use of computers or speaking to anyone.” 5-S 1S Sift and Sort (Organize) 2S Stabilize (Orderliness) 3S Shine (Cleanliness) 4S Standardize (Adherence) 5S Sustain (Self-discipline)
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Price Increase Bigger Profit Cost + Profit = Price Some Profit 3
Price to Sell 1 2 3 Bigger Profit 2 Some Profit Cost to Produce 1 Show left hand side first, 1. Determine Cost to produce an item 2. Add profit you want 3. This gives you Price to the customer If you want to increase your profit under this system, how do you do it? >>> Raise the price to the customer. reveal right hand side This is what most companies operated in the 60’s and 70’s, just pass the cost along to the customer. But as the markets get more and more competitive, do you think this strategy will still work?? NO!! So if Cascade wants to increase their profits now a days, how could they do it?? Discussion Transition to next slide...... Cost + Profit = Price
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Cost Reduction Bigger Profit Price - Cost = Profit Some Profit
Price to Sell 1 1 Some Profit 3 Bigger Profit 3 Cost to Produce 2 2 Show left hand side first, 1. Determine Price customer is willing to pay 2. Subtract the Cost to produce an item 3. This leaves your profit Under this system if you want to increase your profit, how do you do it? >>> Lower Cost. How do you suppose you lower Cost?? Elimination of Non-Value Added Activity. Elimination of Waste !! What exactly is waste? Discussion Price - Cost = Profit
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What value is Added by: Storing Counting Sorting Moving
Acknowledgments Invoices What value is Added by: Expediting Rework Inspecting Discussion None of these activities adds Value. Some are important or necessary, but None add value. Loading / Unloading Scrap Returns to Suppliers Receiving Report Repackaging
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Toyota Production System
Best Quality - Lowest Cost - Shortest Lead Time Through shortening the Production Flow by Eliminating Waste Just in Time “The right part at the right time in the right amount” Jidoka “Built in Quality” Manual / Automatic Line Stop Labor-Machine Efficiency Error Proofing Visual Control Continuous Flow Pull System Level Production (Heijunka) Flexible, Capable, Highly Motivated People Operational Stability Standardized Work Total Productive Maintenance Robust Products & Processes Supplier Involvement
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Very Frequent Change-over
Right Hand Left Hand Left Hand change over Right Hand 8 hours
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Building in Quality JIDOKA
Machines intelligence to be self-operating and self-stopping People served by machines, not vice versa Quality built-in, not inspected-in Efficiency human work separated from machine work, people freed to do value-added work
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Quality as part complexity increases
Number of features P{Good Part} P{Good Part} 3 sigma sigma % % % % % % % % P{good part} = [P{good dimension and good location}]# of features
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Planning for Quality Plan for control limits well outside process variability Monitor the process; not the product Make sure that process/procedures do not go out of control
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Error Proofing Preventing accidental errors in the manufacturing process Error detection Error prevention A way to achieve zero defects.
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Performance barriers Arrivals 60 minutes between parts Service 55 minutes/part
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Performance barriers (con’t)
Arrivals Service Wait in system Constant Constant 0 minutes Random (Poisson) Constant minutes Random (Poisson) Random (Poisson) minutes
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End - Waste Elimination
Questions?
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