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JustInTime and Lean Production

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Cellular layouts. Pull production system. Kanban production control. Small-lot production ... U cell layout, counter clockwise. multi-process handling workers ... – PowerPoint PPT presentation

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Title: JustInTime and Lean Production


1
  • Just-In-Time and Lean Production

2
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.

3
What is JIT ?
  • Producing only what is needed, when it is needed
  • A philosophy
  • An integrated management system
  • JITs mandate Eliminate all waste

4
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

5
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

6
Waste in Operations
Figure 11.1
7
Waste in Operations
Figure 11.1
8
Waste in Operations
Figure 11.1
9
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

10
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

11
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

12
Flexible Resources
  • Multifunctional workers
  • General purpose machines
  • Study operators improve operations

13
Standard Operating Routine for a Worker
Figure 11.2
14
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

15
Manufacturing Cell with Worker Routes
Figure 11.3
16
Worker Routes Lengthened as Volume Decreases
Figure 11.4
17
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

18
Balanced Production
  • TAKT time
  • Objective -- Build at rate that the customer
    wants work
  • Balance the system to maximize
  • efficiency at this rate

19
TAKT Time
  • TAKT
  • the beat
  • (Net Available Operating Time) / Customer
    Requirements
  • time periods must be consistent
  • Example of calculation

20
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"

21
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

22
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

23
A Sample Kanban
24
The Origin of Kanban
Figure 11.5
25
Types of Kanbans
Figure 11.6
26
Types of Kanbans
Figure 11.6
27
Types of Kanbans
Figure 11.6
28
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

29
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
30
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
31
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

32
Inventory Hides Problems
33
Lower Levels of Inventory Expose Problems
34
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

35
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

36
Common Techniques for Reducing Setup Time
Figure 11.8
37
Common Techniques for Reducing Setup Time
Figure 11.8
38
Common Techniques for Reducing Setup Time
Figure 11.8
39
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

40
Mixed-Model Sequencing
Example 11.2
41
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

42
Visual Control
Figure 11.9
43
Visual Control
Figure 11.9
44
Visual Control
Figure 11.9
45
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

46
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

47
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

48
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

49
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

50
JIT Implementation
  • Use JIT to finely tune an operating system
  • Somewhat different in USA than Japan
  • JIT is still evolving
  • JIT isnt for everyone

51
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
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