Just-In-Time

1
Just-In-Time

• Chapter 3

2
JIT Overview

• JIT is both a management philosophy and a set of
  operational techniques.
• An element of the Toyotas Production System
  (VBW, Figure 3.17)
• The philosophy is based on
• Planned elimination of all waste
• Continuous improvement of productivity

3
Sources of Waste

• Overproduction (inventory)
• Defects
• Personnel
• Equipment
• Space
• Time (inefficiency)
• Utilities

4
Major Elements of JIT

• Carry inventory only when needed
• Improve quality to zero defects
• Reduce setup times and lot sizes.
• Focus on continual improvement.
• Make efforts to involve workers and use their
  knowledge to a greater extent.
• Achieve improvement at minimum cost

5
JIT in Manufacturing

• JIT makes major changes in the actual practice of
  manufacturing by reducing
• Complexity of detailed material planning.
• Need for shop-floor tracking.
• Work-in-process inventories.
• Transactions associated with shop-floor and
  purchasing systems.

6
JIT in Services

• Synchronize and balance information and workflow
• Increase process visibility
• Continuously improve processes
• Eliminate all waste (including paperwork)
• Increase resource flexibility

7
JIT and MPC the System(VBW, figure 3.1)
8
JIT and MPC

• Front end
• Level capacity loading
• Engine
• Reduce number of part numbers planned.
• Reduce number of levels in the BOM.
• Back end
• Focus on simplicityshop-floor and purchasing.
• Backflushing.

9
JIT and MPC Building Blocks (Table 3.1, VBW, p.
77)

• Product design
• Standard parts, product simplification, modular
  design, robust design, scheduled design changes,
  design quality
• Process design
• Band widthsurge capacity to accommodate product
  mix and demand variations.
• Process flexibility
• Setup time reduction
• Cellular system

10
JIT and MPC Building Blocks (Table 3.1, VBW, p.
77)

• Human/organizational elements
• Whole person conceptcontinual learning and
  improvement.
• Cross-training
• Motivation and empowerment
• Manufacturing planning/control
• Pull system
• Visibility
• Simplified planning and control

11
JIT ExampleMuth Pots

• Leveling the production
• Pull system introduction
• Material movements and production authorized by
  signal of need from a downstream work center.
• Schedule must be frozen for a period of time.
• Determine the container size/capacity/number.
• Product design
• Process design
• Bill of materials implications

12
JIT Applications

• Single-card kanban system (Figure 3.16, p. 90)
• Two-card kanban system (Toyota)
• Transport, or conveyance, card.
• Production card.
• Two-bin or three-bin system
• Kanban cards replace all work orders and move
  tickets.
• Kanban cards may be used with suppliers.

13
Calculating Number of Kanbans

• Yno. of kanbans
• Ddemand/unit of time 800/day
• Llead time 2 hours0.25 days
• acontainer capacity 20
• ?safety stock 25

14
Control Through Signaling

• Simplicity
• Use different methods kanban, container, tennis
  balls, computerized display board (Andon board),
  etc.
• Planning to schedule/producing to pull signal
• Make or move only with an authorized signal
• First-in, first-out

15
Workplace Organization

• Is referred to as housekeeping
• Is a means to identify and maintain an orderly
  environment
• Is a prerequisite for inventory management
• Prevents errors and contamination
• Basic concepts simplification, organization,
  discipline, cleanliness, participation

16
Six (6) Ss

• Seiri organization
• Seiton tidiness
• Seiso purity
• Seiketsu cleanliness
• Shitsuke discipline
• Shikkari-yarou lets try hard

17
Setup Time

• Internal versus external setup time (setup time
  when the machine is not running)
• Reduce the setup time by studying
• The machine itself
• Attachments
• Tools
• Workplace organization
• Transfer of internal setup to external setup

18
Maintenance

• Focus on preventive maintenance
• Develop a total productive maintenance system
  (TPM)
• Train and assign workers to carry out preventive
  maintenance on their machines
• Provide technical assistance for workers
• Develop a set of measurements for improving the
  maintenance system

19
Flexibility

• Mobility
• Variable output rate
• Multipurpose
• Flexible capability
• Simplicity
• Surge capacity

20
Transportation Strategies

• Repetitive schedules
• Mixed loads
• Milk run
• Freight consolidation
• Local warehouses
• Local suppliers

21
Implication of JIT in Repetitive Systems

• Use production rates instead of work orders
• Gross-only explosions for MRP
• No lead-time offset is required
• Cumulative MRP format may be used
• No need for due dates on individual lots
• Planning buckets are usually in days or weeks

22
Implications of JIT in Job Shop

• Visual control of queues
• The level of BOM is reduced
• Manage the total load of the shop
• Use rate-based scheduling
• Use mixed-model scheduling
• Use cellular layout
• Emphasis part standardization

23
JIT in Purchasing

• Basics
• Scheduling system producing reasonably certain
  requirements.
• Achieving a stable schedule.
• Pursuing all JIT objectives and building blocks.
• Pruning the number of vendors.
• Controlling the cost of transportation.
• Lessons
• Dont shift inventory-holding from the company to
  the vendor.
• Effectively manage vendor relationships.

24
Implication of JIT in Human Resources Management

• Employee involvement and empowerment
• Motivation
• Suggestion systems
• Intra- and inter-functional teams
• Job design
• Compensation and rewards
• Education and training
• Relationships with unions

25
Changing Roles and Responsibilities - Management

• Culture change from maintain status quo to
  improvement
• Supervisors as coaches
• Treat employees fairly
• Sharing information
• Provide support and motivation
• Provide extra time for improvement

26
Changing Roles and Responsibilities - Employees

• Make decisions and solve problems
• Help make improvement
• Work with colleagues closely
• Expanded job responsibilities
• Responsibility at the source
• Use scientific techniques

27
Concluding Principles

• Stabilizing and in some cases leveling the
  production schedules are prerequisites to
  effective JIT systems.
• Achieving very short lead times supports better
  customer service and responsiveness.
• Reducing hidden factory costs can be at least as
  important as reducing costs more usually
  attributed to factory operations.
• Implementing the whole person concept reduces
  distinctions between white- and blue-collar
  workers and taps all persons skills for
  improving performance.

28
Concluding Principles

• Cost accounting and performance measurements need
  to reflect the shift in emphasis away from direct
  labor as the primary source of value added.
• To achieve JITs benefits in nonrepetitive
  applications, some basic features of
  repetitive-based JIT must be modified.
• JIT is not incompatible with MRP-based systems.
  Firms can evolve toward JIT from MRP-based
  systems, adopting JIT as much as or little as
  they want, with an incremental approach.

29
Homework Assignment

• Problem 3.2 and 3.12
• Due Tuesday, December 3