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Lean Manufacturing - An Overview Dr. Richard A. Wysk rwysk@psu.edu http://www.engr.psu.edu/cim Fall 2008. Broad Agenda. Overview of Lean Manufacturing Lean according to R. Wysk Set-up reduction and rapid response production systems Changing in order to change more quickly Case Study
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Lean Manufacturing - An OverviewDr. Richard A. Wyskrwysk@psu.edu http://www.engr.psu.edu/cimFall 2008
Broad Agenda • Overview of Lean Manufacturing • 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
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.
Readings • Chapter 18 of Computer Aided Manufacturing, Wang, H.P., Chang, T.C. and Wysk, R. A., 4th Edition (2008 expected) http://www.engr.psu.edu/cim/ie550/ie550lean.pdf
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
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
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
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.
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 Materials Labor Equipment Energy Methods Products Source: The Machine that Changed the World Womack, Jones, Roos 1990
Product Shipment Product Shipment Lean Manufacturing • is a manufacturing philosophy which shortens the time line between the customer order and the product shipment by eliminating waste. Business as Usual Customer Order Waste Time Lean Manufacturing Customer Order Waste Time (Shorter)
The Nature of Lean Mfg • What Lean Mfg is not • 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.”
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.”
Kaizen Final situation productivity Reengineering Initial situation time 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 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”.
Final situation Kaizen productivity Reengineering Initial situation time 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).
What makes a manufacturing system lean? – the 3 M’s of lean • muda – waste • mura - inconsistency • muri - unreasonableness
Definitions • Systems • Recognition • Efficiencies • Waste • Muda • 7 types • Truly lean
Waste “Anything that adds Cost to the product without adding Value”
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)
7 Forms of Waste CORRECTION MOTION Repair or Rework WAITING 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 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.
Let’s use lean for something we know about – cooking for a party
Excess /Over-production –As applied to fast food preparation • ________________ • ________________ • ________________ • ________________ • ________________ • ________________
Waiting/Delays • __________ • __________ • __________ • __________ • __________ • __________
Transportation/Movement • _________ • _________ • _________ • _________
Inventory • _________ • _________ • _________ • _________
Inspection • __________________ • __________________ • __________________ • ______________ • ______________ • ______________
Corrections and defects • ____________ • ____________ • ____________ • ____________ • ____________
Processing inefficiencies • __________________ • __________________ • __________________ • __________________
Processing inefficiencies • Automatics vs. manual
Over-Processing inefficiencies • Automatics vs. manual • Two people doing some thing that one could do • Workplace layout • Congestion • Labeling
Over-Processing inefficiencies • Material waste
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
Machining example • CNC versus manual • Tool changer • Pallet changer/bar feeder
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: • Part geometry • Tooling
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
The Design Process : Then and Now Before CAD After CAD
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?
CAD/CAM Support • AutoCAD • Pro Engineer • Solidworks • MasterCAM
What do I need to begin MasterCAM? • Part geometry • Draw or import • Tooling • Library or create • Process plans • Fixtures • Define orientation and location
Who wants what... $ Cash !! Value !! Customer Low Cost High Quality Availability Your Company Profit Repeat Business Growth
Elements of Lean Manufacturing • Waste reduction • Continuous flow • Customer pull • 50, 25, 25 (80,10,10) Percent gains
Benefits of Lean Manufacturing • 50 - 80% Waste reduction • WIP • Inventory • Space • Personnel • Product lead times • Travel • Quality, costs, delivery
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
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
Tools (cont.) • Continuous Flow (10% - 25%) • SMED (Shingo) • Andon • Takt time • Line balancing • Nagara (smooth production flow)
Tools (cont.) • Customer pull (10%- 25%) • Just-in-time • Kanban
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
Other Tools • Visual Factory • Error Proofing • Quick Change-over • Total Productive Maintenance