Lean Systems

CHAPTER EIGHT

Lean Systems DefinedLean Systems Defined

8–8–22

• Just-in-time (JIT): an older name for lean systems

• Toyota Production System (TPS): another name for lean systems, specifically as implemented at Toyota

• Lean Systems Approach: a philosophy of minimizing the resources needed for processes

1. What is needed2. At the time needed3. In the amount needed

Lean Systems videoLean Systems video

8–8–33

• http://www.youtube.com/watch?v=c6KVeDbgRgU&feature=related

• http://www.youtube.com/watch?v=6vmdVR9dzPM&feature=related

5 Principles of Lean system5 Principles of Lean system

1. Precisely specify value of each specific product

2. Identify the value stream for each product

3. Make value flow without interruption

4. Let the customer pull value from the producer

5. Pursue perfection

8–8–44

Principle 1: Specify ValuePrinciple 1: Specify Value

• Customers determine value

• Suppliers must provide products/services with customer desired

–Outcomes

–Product features

–Functionality

–Capabilities

Anything that doesn’t add value is waste

8–8–55

Principle 2: Indentify Value StreamPrinciple 2: Indentify Value Stream

8–8–66

1. Overproduction: processing more than needed

2. Waiting: resources waiting for work/materials

3. Transportation: units moved unnecessarily

4. Processing: excessive or unnecessary steps

5. Inventory: units waiting for processing or delivery

6. Motion: unnecessary or excessive resource activity

7. Defects: scrap, rework or correction

Waste is a symptom of a problem, and does not add value

Waste in OperationsWaste in OperationsWaste in OperationsWaste in Operations

Waste in Operations (cont.)Waste in Operations (cont.)Waste in Operations (cont.)Waste in Operations (cont.)

Waste in Operations (cont.)Waste in Operations (cont.)Waste in Operations (cont.)Waste in Operations (cont.)

Principle 3 : Make Value Flow w/o interruption

Principle 3 : Make Value Flow w/o interruption

Inventory hides problems

8–8–1010

Principle 3 : Make Value Flow w/o interruption

Principle 3 : Make Value Flow w/o interruption

8–8–1111

Principle 3 : Make Value Flow w/o interruption

Principle 3 : Make Value Flow w/o interruption

8–8–1212

Principle 4: Customers Pull ValuePrinciple 4: Customers Pull Value

• Pull System: processes are activated by actual, not forecasted demand

• Push system:

• Customers get

– what they want

– when they want

– where they want

8–8–1313

Real world example of Lean Systems videoReal world example of Lean Systems video

8–8–1414

• http://www.youtube.com/watch?v=EEhNkzdKyrw&feature=related

Principle 5: Pursue PerfectionPrinciple 5: Pursue Perfection

• Lean System Culture: places a high value on respect for people–Acceptance: agree to goals, veterans teach new employees

–Flexibility: responsive pull systems

–Teams: cross-functional & cross-organizational

–Employee empowerment: employees work to attack waste

–Manage with data: objective over subjective

–Waste as a symptom: attack root cause

–Goals are met: set realistic, achievable goals

–Standardization: reduces variation, simplifies problem solving

–Process focus: process change for outcome change

8–8–1515

Lean Tools and TechniquesLean Tools and Techniques

• Total Productive Maintenance (TPM): prevention of breakdowns

• Group Technology: bring together resources to process a family of items

• Focused Factories: processes designed to satisfy specific customer segment

8–8–1616

Lean Tools and TechniquesLean Tools and Techniques

• Takt Time: synchronizing output rate with demand rate

• Level, Mixed Model : Apportions batches of each product to be produced evenly throughout the day

8–8–1717

Lean Tools and TechniquesLean Tools and Techniques

• Kanban (Pull): output generated in response to actual demand, –production kanban,

–withdrawal kanban

8–8–1818

Lean Tools and Techniques cont’dLean Tools and Techniques cont’d

• Set-up Reduction: shorter, easier change- over leads to smaller batches

–Single Minute Exchange of Dies (SMED): Process for reducing set-up

8–8–1919

• Internal setup–Can be

performed only when a process is stopped

• External setup–Can be

performed in advance

• SMED(single-minute exchange of die) Principles– Separate internal setup

from external setup– Convert internal setup to

external setup– Streamline all activities in a

setup

Lean Tools and Techniques cont’dLean Tools and Techniques cont’d

• Statistical Process Control (SPC): use of statistical tools to monitor processes

• Visual Control: performance and problems easily, immediately visible

–Bulletin boards

–SPC charts

–Large electronic displays

–Lighting systems

8–8–2020

Lean Tools and Techniques cont’dLean Tools and Techniques cont’d

• Quality at the source : Eliminating defects at their origination points

–Jidoka

–Stop-and Fix System

–Andons

• Kaizen Events: short-term, cross-functional focused, intense process improvement

–Gemba Kaizen: go see it in person

8–8–2121

Lean Tools and Techniques cont’dLean Tools and Techniques cont’d

• 5-S: effective housekeeping (sort, straighten, scrub, systematize, standardize)

1.Sort: decide which items are needed to accomplish the work, and keep only items.

2.Straighten: organize the workplace so that the needed items can be accessed quickly and easily

3. Scrub: keep the workplace clean and ready for work. Perform equipment maintenance regularly.

4. Systematize: make cleaning and checking routine

5. Standardize: Standardize the previous four steps into one process and continuously improve it.

8–8–2222

Real world example of 5-s (LMI inc.)Real world example of 5-s (LMI inc.)

8–8–2323

Real world example of 5-s (LMI inc.)Real world example of 5-s (LMI inc.)

8–8–2424

Lean Tools and Techniques cont’dLean Tools and Techniques cont’d

• Poka-Yoke: redesign so mistakes are impossible or immediately detectable

• Simplification/Standardization: removing non-value add steps, making processes exactly repeatable

8–8–2525

Comparison of JIT and TraditionalComparison of JIT and TraditionalComparison of JIT and TraditionalComparison of JIT and Traditional

Factor Traditional JIT

Inventory Much to offset forecast errors, late deliveries

Minimal necessary to operate

Deliveries Few, large Many, small

Lot sizes Large Small

Setup; runs Few, long runs Many, short runs

Vendors Long-term relationships are unusual

Partners

Workers Necessary to do the work Assets

Homework problems in ch 8Homework problems in ch 8

• Do problems of 2,3,4,10, and 15 on page 256 and 257

8–8–2727