Transcript Just-in-Time (JIT) and Lean Systems

Just-in-Time (JIT) and Lean Systems
Chapter 7
MGMT 326
Foundations
of Operations
Products &
Processes
Quality
Assurance
Introduction
Managing
Projects
Managing
Quality
Product
Design
Statistical
Process
Control
Strategy
Process
Design
Just-in-Time & Lean Systems
Capacity
and
Facilities
Planning
& Control
Presentation Outline
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The philosophy of JIT
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7 Elements of JIT Philosophy
Examples of waste
3 key principles of JIT
JIT in services
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Principles of lean processes (JIT) in services
Presentation Outline (2)
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JIT in manufacturing
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Inventory reduction
 Cost of inventory
 Kanban pull system
 Small lot sizes and quick setups
 Uniform plant loading
 Flexible resources (people & equipment)
 Efficient plant layouts
Presentation Outline (3)
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Other topics in JIT and lean systems
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Respect for people: the role of employees
The role of managers
Benefits of JIT and lean systems
Just-in-Time & Lean Systems
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Just-in-time: an operations system for producing
the right goods and services in the right place, at
the right time, in a quality manner
Lean systems: A broad view of JIT that shows how
the entire organization contributes to JIT production
(of goods and services), customer service, and
customer satisfaction
Value-adding activities
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2.
Necessary steps in completing a product or service
Customer service activities that increase the value of the
service to customers
The Philosophy of JIT
7 Elements of JIT Philosophy
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All waste must be eliminated- non value items
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Waste is any amount of a resource that is not required
to produce and deliver a quality good or service when
it is needed
Broad view that entire organization must focus on
serving customers
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Serving customers requires cooperation throughout the
organization
The Philosophy of JIT (2)
7 Elements of JIT Philosophy (2)
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JIT is built on simplicity - the simpler the better
Focuses on improving every operation- Kaizen
Install simple, visible control systems
Provide flexibility to produce different
models/features
The same philosophy also applies in Lean
Systems
Examples of Waste
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Producing items before
they are needed
Waiting time: high WIP,
idle machines, or idle
people
Needless movement of
materials or people
Unneeded process steps
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Inventory
Searching for materials,
tools, etc.
Defects
People who are not
challenged by their jobs
and are not allowed to
give input into decisions
3 Key Principles of JIT
and Lean Systems
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Just-in-time processes
Total quality management
Respect for people
Elements of Lean Systems
in Services
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Improved quality – consistency
Uniform facility loading when possible
Multifunctional workers
More efficient processes and shorter cycle
time
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Shorter setup times
Parallel processing
Clean, well-organized workplace
See pages 244-245 for details
Elements of JIT Manufacturing
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Inventory reduction exposes problems
Kanbans & pull production systems
Small lots & quick setups
Uniform plant loading
Flexible resources
Efficient facility layouts (cellular layout)
Role of Inventory Reduction
("Rocks in the Stream")
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Inventory = Lead Time (less is better)
Inventory hides problems (Figure 7-2, page 225)
Cost Impact of Inventory
Figure 7-2, page 225
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High inventory  high inventory holding
costs
High inventory hides problems, and the
company pays for the cost of the problems
In manufacturing, high inventory requires
large lot sizes
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Long manufacturing lead times
Harder to meet changing customer demand
Delays in introducing new or improved products
Reducing Inventory
Kanban Pull System (Figure 7-3, p. 229)
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Production kanban: authorization to make a container
of parts
 No production can be done without a production
kanban and an empty container
Withdrawal kanban: authorization to get a container
of parts for use in the next process step
Work in process (WIP) inventory
 WIP < (number of kanbans)(lot size)
 Lot size = number of parts of a certain type
produced at one time
Reducing Inventory
Small Lot Sizes and Quick Setups
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Benefits of small lot sizes
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Shorter manufacturing lead time  Faster
response to changes in customer demand
Lower inventory and inventory holding costs
Small lot sizes require more setups
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Setups must be done more quickly and at lower
costs. This is necessary
 To ensure adequate capacity
 To control setup costs
 To avoid production delays
Inventory Reduction
Uniform Plant Loading
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A “level” schedule is developed so that the same mix
of products is made every day in small quantities
Leveling the schedule reduces inventory along the
whole supply chain
See Table 7-1, page 233
JIT in Manufacturing
Flexible Resources
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Moveable, general purpose equipment:
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Portable equipment with plug in power/air
E.g.: drills, lathes, printer-fax-copiers, etc.
Capable of being setup to do many different things with
minimal setup time
Multifunctional workers:
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Workers assume considerable responsibility
Cross-trained to perform several different duties
Trained to also be problem solvers
JIT in Manufacturing
Effective Facility Layouts
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Workstations in close physical proximity to reduce
transport & movement
Streamlined flow of material
Often use:
 Cellular Manufacturing (instead of process focus) –
reduces WIP, transportation time and costs
 U-shaped lines: (allows material handler to quickly
drop off materials & pick up finished work)
Cellular Manufacturing Layout
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Traditional process-focus layout: jumbled flow, long
production lead time (cycle time), hard to schedule
Cellular manufacturing layout: each cell makes a
family of parts or products with similar manufacturing
requirements
 Highly visible schedule, problems are apparent,
easy to schedule, short production lead time
 More flexible than assembly line. More efficient
than batch production.
See Figure 7-6, page 235
JIT and TQM
TQM = Total Quality Management
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Build quality into all processes
Focus on continuous improvement - Kaizen
Quality at the source - immediate inspection
Jidoka (authority to stop line)
Poka-yoke (fail-safe all processes)
Preventive maintenance- scheduled
Work environment- everything in its place, a place for
everything
Respect for People:
The Role of Employees
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Genuine and meaningful respect for associates
Willingness to develop cross-functional skills
Actively engage in problem-solving (quality circles)
Everyone is empowered
Everyone is responsible for quality: understand both
internal and external customer needs
Respect for People: The Role of
Employees
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Associates gather performance data
Team approaches used for problem-solving
Many decisions are made from the bottom up
Everyone (in a manufacturing plant) is responsible for
preventive maintenance
The Role of Management
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Responsible for culture of mutual trust
Serve as coaches & facilitators
Support culture with appropriate incentive
system including non-monetary
Responsible for developing workers
Provide multi-functional training
Facilitate teamwork
Benefits of JIT and Lean Systems
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Smaller inventories
Shorter lead times
Improved quality
Reduced space requirements
Lower operations costs
Increased productivity
Greater product flexibility