JustInTime and Lean Production

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• Just-In-Time and Lean Production

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JIT Definitions?

• JIT Head
• Chicken JIT
• Oh JIT (OJIT)
• Tough JIT
• Strate JITs

• JIT Planes
• Bull JIT
• Le JIT
• JIT Lag
• When the JIT hits the fan.

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What is JIT ?

• Producing only what is needed, when it is needed
• A philosophy
• An integrated management system
• JITs mandate Eliminate all waste

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What is JIT?

• a corporate system designed to produce output
  within the minimum lead time and at the lowest
  total cost by continuously identifying and
  eliminating all forms of corporate waste and
  variance.
• a corporate strategy
• a philosophy
• Focus of JIT
• variance waste

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Seven Basic Types of Waste

• Waste from overproduction
• Waste from waiting times
• Transportation waste
• Process Waste
• Inventory Waste
• Waste of motion
• Waste from product defects

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Waste in Operations
Figure 11.1
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Waste in Operations
Figure 11.1
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Waste in Operations
Figure 11.1
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Common Causes of Waste

• Layout (distance)
• Long setup time
• Incapable processes
• Poor maintenance
• Poor work methods
• Lack of training

• Inconsistent performance measures
• Ineffective production planning
• Lack of workplace organization
• Poor supply quality/reliability

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Objectives of JIT

• Produce only the products the customer wants.
• Produce products only at the rate that the
  customer wants them.
• Produce with perfect quality
• Produce with minimum lead time.
• Produce products with only those features the
  customer wants.
• Produce with no waste of labor, material or
  equipment -- every movement must have a purpose
  so that there is zero idle inventory.
• Produce with methods that allow for the
  development of people

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Basic Elements of JIT

• Flexible resources
• Cellular layouts
• Pull production system
• Kanban production control
• Small-lot production
• Quick setups
• Uniform production levels
• Quality at the source
• Total productive maintenance
• Supplier networks

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Flexible Resources

• Multifunctional workers
• General purpose machines
• Study operators improve operations

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Standard Operating Routine for a Worker
Figure 11.2
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Cellular Layouts

• Group dissimilar machines in manufacturing cell
  to produce family of parts
• Work flows in one direction through cell
• Cycle time adjusted by changing worker paths

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Manufacturing Cell with Worker Routes
Figure 11.3
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Worker Routes Lengthened as Volume Decreases
Figure 11.4
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JIT Principles

• Create flow production
• one piece flow
• machines in order of processes
• small and inexpensive equipment
• U cell layout, counter clockwise
• multi-process handling workers
• easy moving/standing operations
• standard operations defined

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Balanced Production

• TAKT time
• Objective -- Build at rate that the customer
  wants work
• Balance the system to maximize
• efficiency at this rate

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TAKT Time

• TAKT
• the beat
• (Net Available Operating Time) / Customer
  Requirements
• time periods must be consistent
• Example of calculation

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TAKT Time Example

• Net Available Operating Time
• Time per shift 480
• Breaks (2 _at_ 10) - 20
• Clean-up - 20
• Lunch - 30
• NAOT/shift 410
• Customer Requirements
• Monthly 26,000
• No. Working Days 20
• CR/Day 1,300
• T/T
• 410/shift60"/min3 shifts/1,300
• 56.769" per part or 57"

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The Pull System

• Material is pulled through the system when needed
• Reversal of traditional push system where
  material is pushed according to a schedule
• Forces cooperation
• Prevent over and underproduction

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Kanban Production Control System

• Kanban card indicates standard quantity of
  production
• Derived from two-bin inventory system
• Kanban maintains discipline of pull production
• Production kanban authorizes production
• Withdrawal kanban authorizes movement of goods

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A Sample Kanban
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The Origin of Kanban
Figure 11.5
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Types of Kanbans
Figure 11.6
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Types of Kanbans
Figure 11.6
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Types of Kanbans
Figure 11.6
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Types of Kanbans

• Kanban Square
• Marked area designed to hold items
• Signal Kanban
• Triangular kanban used to signal production at
  the previous workstation
• Material Kanban
• Used to order material in advance of a process
• Supplier Kanbans
• Rotate between the factory and suppliers

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Determining Number of Kanbans
where N number of kanbans or containers d
average demand over some time period L
lead time to replenish an order S safety
stock C container size
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Determining the Number of Kanbans
d 150 bottles per hour L 30 minutes 0.5
hours S 0.10(150 x 0.5) 7.5 C 25 bottles
Round up to 4 (to allow some slack) or down to 3
(to force improvement)
Example 11.1
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Small-Lot Production

• Requires less space capital investment
• Moves processes closer together
• Makes quality problems easier to detect
• Makes processes more dependent on each other

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Inventory Hides Problems
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Lower Levels of Inventory Expose Problems
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Components of Lead Time

• Processing time
• Reduce number of items or improve efficiency
• Move time
• Reduce distances, simplify movements, standardize
  routings
• Waiting time
• Better scheduling, sufficient capacity
• Setup time
• Generally the biggest bottleneck

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SMED Principles

• Separate internal setup from external setup
• Convert internal setup to external setup
• Streamline all aspects of setup
• Perform setup activities in parallel or eliminate
  them entirely

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Common Techniques for Reducing Setup Time
Figure 11.8
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Common Techniques for Reducing Setup Time
Figure 11.8
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Common Techniques for Reducing Setup Time
Figure 11.8
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Uniform Production

• Results from smoothing production requirements
• Kanban systems can handle /- 10 demand changes
• Smooths demand across planning horizon
• Mixed-model assembly steadies component production

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Mixed-Model Sequencing
Example 11.2
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Quality at the Source

• Jidoka is authority to stop production line
• Andon lights signal quality problems
• Undercapacity scheduling allows for planning,
  problem solving maintenance
• Visual control makes problems visible
• Poka-yoke prevents defects

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Visual Control
Figure 11.9
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Visual Control
Figure 11.9
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Visual Control
Figure 11.9
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Kaizen

• Continuous improvement
• Requires total employment involvement
• Essence of JIT is willingness of workers to
• Spot quality problems
• Halt production when necessary
• Generate ideas for improvement
• Analyze problems
• Perform different functions

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Total Productive Maintenance (TPM)

• Breakdown maintenance
• Repairs to make failed machine operational
• Preventive maintenance
• System of periodic inspection maintenance to
  keep machines operating
• TPM combines preventive maintenance total
  quality concepts

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TPM Requires Management to

• Design products that can be easily produced on
  existing machines
• Design machines for easier operation, changeover,
  maintenance
• Train retrain workers to operate machines
• Purchase machines that maximize productive
  potential
• Design preventive maintenance plan spanning life
  of machine

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Supplier Policies

• Locate near to the customer
• Use small, side loaded trucks and ship mixed
  loads
• Consider establishing small warehouses near to
  the customer or consolidating warehouses with
  other suppliers
• Use standardized containers and make deliveries
  according to a precise delivery schedule
• Become a certified supplier and accept payment at
  regular intervals rather than upon delivery

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Benefits of JIT

• Reduced inventory
• Improved quality
• Lower costs
• Reduced space requirements
• Shorter lead time
• Increased productivity
• Greater flexibility

• Better relations with suppliers
• Simplified scheduling and control activities
• Increased capacity
• Better use of human resources
• More product variety

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JIT Implementation

• Use JIT to finely tune an operating system
• Somewhat different in USA than Japan
• JIT is still evolving
• JIT isnt for everyone

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JIT In Services

• Competition on speed quality
• Multifunctional department store workers
• Work cells at fast-food restaurants
• Just-in-time publishing for textbooks
• Construction firms receiving material just as
  needed