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 Toyota’s 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: Engine: Back end: Level capacity loading
Reduce number of part numbers planned.
Reduce number of levels in the BOM.
Back end:
Focus on simplicity—shop-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 width—surge 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 concept—continual learning and improvement.
Cross-training
Motivation and empowerment
Manufacturing planning/control
Pull system
Visibility
Simplified planning and control

11. JIT Example—Muth 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
Y=no. of kanbans
D=demand/unit of time [800/day]
L=lead time [2 hours=0.25 days]
a=container 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) S’s Seiri – organization Seiton –tidiness Seiso –purity
Seiketsu – cleanliness
Shitsuke – discipline
Shikkari-yarou – let’s 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: Lessons
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
Don’t 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 JIT’s 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