Introduction to Lean Introduction to Lean ManufacturingManufacturing

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Lean Manufacturing Lean Manufacturing DefinitionDefinition

Lean has been defined in many different ways.Lean has been defined in many different ways.

““A systematic approach to A systematic approach to identifying and identifying and eliminating wasteeliminating waste(non-value-added activities) (non-value-added activities) through through continuous improvementcontinuous improvement by flowing the by flowing the product at the product at the pullpull of the customer in pursuit of of the customer in pursuit of perfection.”perfection.”

By The MEP Lean NetworkBy The MEP Lean Network

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History Timeline for Lean ManufacturingHistory Timeline for Lean Manufacturing

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Lean manufacturing is a Lean manufacturing is a philosophyphilosophyIn 1990 James Womack, Daniel T. Jones,

and Daniel Roos wrote a book called “The Machine That Changed the World: The Story of Lean Production-- Toyota's Secret Weapon in the Global Car Wars That Is Now Revolutionizing World Industry”

In this book, Womack introduced the Toyota Production System to American.

What was new was a phrase– "Lean Manufacturing."

How to Increase Profit?How to Increase Profit?

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Muda (Waste)Muda (Waste)Taiichi Ohno (1912-1990), the Toyota executive who was the Taiichi Ohno (1912-1990), the Toyota executive who was the most ferocious foe of waste human history has produced, most ferocious foe of waste human history has produced, identified the first seven types of identified the first seven types of mudamuda in manufacturing in manufacturing system:system:

•StorageStorage•TransportationTransportation•WaitingWaiting•MotionMotion•ProcessProcess•DefectsDefects•Over-productionOver-production

MudaMuda is everywhere. is everywhere.

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Lean OverviewLean Overview

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Lean Manufacturing ToolsLean Manufacturing Tools 5S5S Value Stream MappingValue Stream Mapping Standardized WorkStandardized Work Load LevelingLoad Leveling KaizenKaizen KanbanKanban Visual WorkplaceVisual Workplace Quick ChangeoverQuick Changeover AndonAndon Poka-yokePoka-yokeOne-piece flowOne-piece flowCellular ManufacturingCellular Manufacturing

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Production Planning System (Push Production Planning System (Push System)System)

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Push or Pull?Push or Pull?

A push system

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Push or Pull?Push or Pull?

A pull system

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Kanban Operation

WK(2)PK(1) PK(i+1)PK(2) PK(N)WK(1) WK(N)WK(i+1)WK(i) PK(i)

RM FG

Kanban Stage1

Kanban Stagei

Station1

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Figure 3.3. A kanban stage formed by two adjacent stations.

From stage i-1 To stage i+1

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Finished goods

Raw materials inventory

Semi-finished parts

PKPK PK WKWKWK

Station 1 Station 2

Station 3

Semi-finished parts

Material handler Order

receiving

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Current State Map of A Case Study Example

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Future State MapAt which stations, are parts withdrawn? At which stations, are parts scheduled?

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Which to Choose — MRP Which to Choose — MRP (ERP), or Kanban?(ERP), or Kanban?Where MRP (ERP) works best:

MRP is by its very nature a forward-looking system.

MRP can be very effective in an environment with a great deal of variability.

MRP is recognized an engine to drive an integrated enterprise-wide information system. Purchasing and logistics activities were similarly being integrated with fundamental internal materials management principles into an enterprise-wide approach.

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MRP or Lean Manufacturing?MRP or Lean Manufacturing?

MRP is a predictive system. It does not reflect to customer’s demand (easy to get overproduction).

A company takes MRP suggestions and acts on them without too much review is very risky.

MRP won’t fully support the cost-cutting. MRP needs lots of data for production management. MRP generates high overhead. MRP builds high work-in-process. MRP’s lead times are fixed. MRP creates potential quality hazard.

Where MRP is not as effective.

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Which to Choose — MRP Which to Choose — MRP (ERP), or Kanban?(ERP), or Kanban?

Where Kanban works best.Where Kanban works best. Kanban is a very reactive system. Very little is Kanban is a very reactive system. Very little is

planned ahead. Instead, Kanban causes replacement of planned ahead. Instead, Kanban causes replacement of material used in a totally reactive mode. Kanban works material used in a totally reactive mode. Kanban works best in a highly stable and predictable environment.best in a highly stable and predictable environment.

Where it is not as effective. Kanban can quickly fail in a highly volatile

environment because of the reactive nature of the system. Volatility in customer demand, processing problems, and extensive changes in product designs make it very difficult for a Kanban system to work effectively.

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Which to Choose — MRP Which to Choose — MRP (ERP), or Kanban?(ERP), or Kanban?

Kanban and MRP CombinationKanban and MRP Combination

The combination of these two systems is becoming The combination of these two systems is becoming quite common. An MRP system is used for advanced quite common. An MRP system is used for advanced planning, including long lead-time purchased materials, planning, including long lead-time purchased materials, adding resources, and implementing product design adding resources, and implementing product design changes. Once the MRP has the materials and resources changes. Once the MRP has the materials and resources “lined up,” however, Kanban is used as an execution system, “lined up,” however, Kanban is used as an execution system, bringing with the characteristics of rapid response to bringing with the characteristics of rapid response to customer order and reduced inventory levels throughout the customer order and reduced inventory levels throughout the process.process.

Hybrid SystemsHybrid Systems

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The Objections to LeanThe Objections to LeanHow should you deal with these objections to lean?

•“It is very hard to deal with raw material suppliers if we fully depend on customer order.”

•“It takes too much discipline.”

•“It takes too long to implement.”

•“My process is too complex; I have to deal with too many uncontrollable variables, like late supplier shipments, sick people, etc.”

•“My process requires a large batch size.”

•“It doesn’t make sense in my industry.”

•“It’s unclear to me how lean will work with my MRP system.”

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Lean and GreenLean and Green

The environmental impacts due to production and waste generation have made its way into every day society.Consumers are becoming more environmentally conscious. With the Earth’s limited resources, companies are more conscious of their carbon footprint, and there has been a movement to create more environmentally friendly decisions.

Green engineering is the systems-level approach to product and process design where environmental attributes are treated as primary objectives or opportunities rather than simple constraints.

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lean manufacturing is a linklean manufacturing is a link to green engineering to green engineering

Lean manufacturing is the business model and collection of tactical methods that emphasize eliminating non-value- added activities (waste) while delivering quality products at lowest cost with greater efficiency. In conjunction, six goals of green engineering are:

1. Select low environmental impact materials.

2. Avoid toxic or hazardous materials.

3. Choose cleaner production processes.

4. Maximize energy and water efficiencies.

5. Design for waste minimization.

6. Design for recyclability and reuse of material.

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lean manufacturing is a linklean manufacturing is a link to green engineering to green engineering

Population growsWastes increaseFossil fuels are diminishing and there is nothing replenishing them. Consumers are becoming more aware of the environment and prefer environmentally friendly companies.

Being lean and green is so important now to reduce the consumption of natural resources and the CO2 concentration in the Earth’s atmosphere.

The only real difference between lean and green manufacturing is that green actually designs the product or process with the environment as a constraint while lean creates a process with the view of the environment as a valuable resource and not a constraint.

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Key Steps in TransformingKey Steps in Transforminga Company to the Lean a Company to the Lean ApproachApproach1.1. Establish a steering team—conduct strategic planning sessionEstablish a steering team—conduct strategic planning session2.2. Train the steering team and the model line team in the Train the steering team and the model line team in the

disciplines of leandisciplines of lean3.3. Perform PQR (product-quantity-routing) analysisPerform PQR (product-quantity-routing) analysis4.4. Identify value streams—select a value streamIdentify value streams—select a value stream5.5. Calculate model line takt timeCalculate model line takt time6.6. Value stream map the model line—assemble current state Value stream map the model line—assemble current state

mapmap7.7. Balance the line—assign standard workBalance the line—assign standard work8.8. Establish standard WIP (inventory levels)Establish standard WIP (inventory levels)9.9. Test the system (virtual cell)—document resultsTest the system (virtual cell)—document results10.10. Setup reduction eventSetup reduction event

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Key Steps in TransformingKey Steps in Transforminga Company to the Lean a Company to the Lean ApproachApproach

11.11.Conduct 5S event—apply TPM techniquesConduct 5S event—apply TPM techniques12.12.Establish visual signals—reduce paperworkEstablish visual signals—reduce paperwork13.13.Explore alternative flow patternsExplore alternative flow patterns14.14.Develop block layoutDevelop block layout15.15.Develop detailed layoutDevelop detailed layout16.16.Execute moveExecute move17.17.Select next value stream and repeatSelect next value stream and repeat

Gary Conner, President of Lean Enterprise Training, Newport, OR, Road Map to Lean for the Smaller Shop, Society of Manufacturing Engineers, Lean Manufacturing 2007, Supplement to Manufacturing Engineering, 2007. pp. 27-29.

ReferencesReferences

• Society of Manufacturing Engineers, Society of Manufacturing Engineers, Lean Manufacturing 2007, Lean Manufacturing 2007, Supplement to Manufacturing EngineeringSupplement to Manufacturing Engineering, 2007., 2007.

• Society of Manufacturing Engineers, Society of Manufacturing Engineers, Lean Manufacturing 2008, Lean Manufacturing 2008, Supplement to Manufacturing EngineeringSupplement to Manufacturing Engineering, 2008., 2008.

• Garrett Brown and Dara O’Rourke, “Garrett Brown and Dara O’Rourke, “LeanLean ManufacturingManufacturing ComesComes toto ChinaChina: A Case Study of its Impact on Workplace Health and Safety,” : A Case Study of its Impact on Workplace Health and Safety,” International Journal of Occupational and Environmental Health (IJOEH)International Journal of Occupational and Environmental Health (IJOEH), , 13(3), JUL/SEP 2007. 13(3), JUL/SEP 2007.

• Challenges in Applying Lean Manufacturing in China, Challenges in Applying Lean Manufacturing in China, McKinsey McKinsey Quarterly, 2006 Special Edition Quarterly, 2006 Special Edition available at Jackson Library. Friday, available at Jackson Library. Friday, October 12, 2007 | Posted by October 12, 2007 | Posted by Simone Yu in in International

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