Lean, JIT

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Lean, JIT Japanese Manufacturing

• ISQA 511

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Lean vs. JIT

• Lean Video

• Jit

• Resource Minimization
• Value-add
• Flexibility of Workers Equipment
• Total Cost

• High volume-low inventory
• Eliminate Waste
• Resources arrive just in time.

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Japanese Manufacturing (TPS)is holistic not just
pulling out things we like!

• Elimination of waste
• Efforts concentrated on all operations
• Respect for people
• Quality improvement focus
• How does this align with principles of
  sustainability?

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Waste in Operations

• (1) Waste from overproduction
• (2) Waste of waiting time
• (3) Transportation waste
• (4) Inventory waste
• (5) Processing waste
• (6) Waste of motion
• (7) Waste from product defects
• (8) Wasting our human resources ?

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Demand-Pull Logic
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Minimizing Waste Focused Factory Networks
Coordination
System Integration
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Traditional Conveyance
Sporadic and Infrequent Deliveries from
Individual Suppliers
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Mixed-Load Delivery
Regular and Frequent Deliveries from Many
Suppliers
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Minimizing Waste Group Technology

• Using Departmental Specialization for plant
  layout can cause a lot of unnecessary material
  movement.

Saw
Saw
Grinder
Saw
Grinder
Heat Treat
Lathe
Press
Press
Lathe
Lathe
Press
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Minimizing Waste Group Technology

• Revising by using Group Technology Cells can
  reduce movement and improve product flow.

Grinder
2
1
Press
Lathe
Lathe
Saw
Heat Treat
Grinder
Press
A
B
Lathe
Lathe
Saw
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Minimizing Waste Uniform Plant Loading
Suppose we operate a production plant that
produces a single product. The schedule of
production for this product could be accomplished
using either of the two plant loading schedules
below.
Not uniform Jan. Units Feb. Units Mar.
Units Total 1,200 3,500 4,300 9,000
or
Uniform Jan. Units Feb. Units Mar.
Units Total 3,000 3,000 3,000 9,000
How do the different methods impact workers?
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Mixed Batch Example

• Company produces three products with a mixed
  model assembly line.
• Operates 16 hours per day for 250 days/yr.
• Determine the mixed model MPS for a daily batch.
• Determine minimum batch MPS and the mix schedule
  for a day.

Products Forecasts (year)
1 20,000
2 10,000
3 5,000
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Calculations
    1 2 3
Year Forecast   20000 10000 5000
Daily Batch divide by 250 80 40 20
Hourly Batch divide by 16 5 2.5 1.25
Minimum Batch MPS   4 2 1
For every unit of 3 (minimum batch), we need
twice as many 2 and 4 times As many 1 so for
minimum batch Produce during each day produce
1,1,1,1,2,2,3 - repeated 20 times
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Mixed Batch Example

• Company produces four products with a mixed model
  assembly line.
• Operates 8hours per day for 250 days/yr.
• Determine the mixed model MPS for a daily and
  hourly batch .
• Determine mix schedule for a day.

Products Forecasts (year)
I 500
II 1500
III 4500
IV 6000
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Mixed Batch

• What is the relationship with inventory
  reduction?
• What kind of workers are required?
• Is the job better or worse from their
  perspective?
• What are hiring training implications?

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Minimizing Waste Kanban Production Control
Systems
Withdrawal kanban
Storage Part A
Storage Part A
Machine Center
Assembly Line
Material Flow Card (signal) Flow
Production kanban
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Determining the Number of Kanbans Needed

• Setting up a kanban system requires determining
  the number of kanbans (or containers) needed.
• Each container represents the minimum production
  lot size.
• An accurate estimate of the lead time required to
  produce a container is key to determining how
  many kanbans are required.

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The Number of Kanban Card Sets
k Number of kanban sets (a set is a card and/or
containers) d Average number of units demanded
over some time period L lead time to replenish
an order (same units of time as demand) S
Safety stock expressed as a percentage of demand
during lead time C Container size
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Example of Kanban Card Determination Problem Data

• A switch assembly is assembled in batches of 4
  units from an upstream assembly area and
  delivered in a special container to a
  downstream control-panel assembly operation.
• The control-panel assembly area requires 5 switch
  assemblies per hour.
• The switch assembly area can produce a container
  of switch assemblies in 2 hours.
• Safety stock has been set at 10 of needed
  inventory.

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JIT Requirements Design Flow Process

• Link operations
• Balance workstation capacities
• Re-layout for flow
• Emphasize preventive maintenance
• Reduce lot sizes
• Reduce setup/changeover time

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JIT Requirements Improve Product Design

• Standard product configuration
• Standardize and reduce number of parts
• Process design with product design
• Quality expectations

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Respect for People

• Level payrolls
• Cooperative employee unions
• Subcontractor networks
• Inverted pyramid management style
• Small group involvement activities

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Requirements Total Quality Control

• Worker responsibility
• Measure Reduce Variation (SPC)
• Enforce compliance
• Fail-safe (Poke-yoke) methods
• Automatic inspection vs. people inspection

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POKE-YOKES address Mistakes (What are ideas for
surgery?)

• Defects

• Mistakes

• Omitting a part or process
• Performing a process incorrectly, wrong process
  or on the wrong part
• Performing a process in improper environmental
  conditions
• Setting up equipment or work piece incorrectly
• Adjusting equipment incorrectly
• Tooling set up or adjusted incorrectly
• Installing wrong part or incorrectly

• Damaged parts
• Missing parts
• Reversed parts
• Wrong parts
• Wrong size or shape
• Wrong chemical properties
• Wrong physical properties
• Wrong item shipped
• Wrong label
• Wrong package
• Damaged finished product

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Other Fun Japanese Words

• Heijunka- level work load, reduce set-up times,
  and variabilities
• Jidoka- stop process immediately to address
  problem (using Andon cord or signal)
• Kaizen-change for good (process quality
  improvement)
• Muda-waste
• Mizusumashi (water spider) person who stocks
  bins
• Others
• http//www.velaction.com/lean-information-velactio
  n/navigating-site/lean-terms/japanese-lean-term-in
  dex/

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5 S system (organizing workplace)
Japanese S English
Seiri Sorting
Seiton Simplifying access (set in order)
Seiso Sweeping (or Shine)
Seiketsu Standardization
Shitsuke Self-Discipline (or Sustain)
5 S Gone Wild