Transcript Production and Operations Management: Manufacturing and

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Chapter 12
Lean Manufacturing
(Just-in-Time)
McGraw-Hill/Irwin
©2009 The McGraw-Hill Companies, All Rights Reserved
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Lean Production
• Lean Production can be defined as
an integrated set of activities
designed to achieve high-volume
production using minimal
inventories (raw materials, work in
process, and finished goods)
• Lean Production also involves the
elimination of waste in production
effort
• Lean Production also involves the
timing of production resources
(i.e., parts arrive at the next
workstation “just in time”)
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JIT is an integrated set of activities designed to...
• achieve high-volume production
using minimal inventories
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raw materials
work in process, and
finished goods.
• Parts arrive at the next workstation
"just in time".
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Just-In-Time Production
WHAT IT IS
• Management philosophy
• Pull system though the plant
WHAT IT REQUIRES
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Employee participation
Industrial engineering/basics
Continuing improvement
Total quality control
Small lot sizes
WHAT IT DOES
• Attacks waste
• Exposes problems and bottlenecks
• Achieves streamlined production
WHAT IT ASSUMES
• Stable environment
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Minimizing Waste: Inventory
Hides Problems
Machine
downtime
Scrap
Work in
process
queues
(banks)
Paperwork
backlog
Vendor
delinquencies Change
orders
Engineering design
redundancies
Inspection
backlogs
Example: By
identifying defective
items from a vendor
early in the
production process
the downstream work
is saved
Design
backlogs
Decision
backlogs
Example: By
identifying defective
work by employees
upstream, the
downstream work is
saved
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Waste--Operations
(1) Waste from overproduction
(2) Waste of waiting time
(3) Transportation waste
(4) Inventory waste
(5) Processing waste
(6) Waste of motion
(7) Waste from product defects
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Minimizing Waste:
JIT Production
Produce...
...what is needed...
...when it’s needed...
...NOTHING MORE!
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Minimizing Waste:
Quality at the Source
• Self-inspection
• Automated inspection
• Line-stopping empowerment
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Minimizing Waste: Kanban Production Control Systems
Once the Production kanban is
received, the Machine Center
produces a unit to replace the
one taken by the Assembly Line
people in the first place
Machine
Center
Withdrawal
kanban
Storage
Part A
Production kanban
The process begins by the Assembly Line
people pulling Part A from Storage
Storage
Part A
This puts the
system back
were it was
before the item
was pulled
Assembly
Line
Material Flow
Card (signal) Flow
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Respect for People
• Level payrolls
• Cooperative employee unions
• Subcontractor networks
• Bottom-round management style
• Quality circles (Small Group
Involvement Activities or SGIA’s)
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Toyota Production System’s Four Rules
1. All work shall be highly specified as to
content, sequence, timing, and
outcome
2. Every customer-supplier connection
must be direct, and there must be an
unambiguous yes-or-no way to send
requests and receive responses
3. The pathway for every product and
service must be simple and direct
4. Any improvement must be made in
accordance with the scientific method,
under the guidance of a teacher, at the
lowest possible level in the
organization
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Lean Implementation Requirements: Work with Vendors
• Reduce lead times
• Frequent deliveries
• Project usage requirements
• Quality expectations
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Lean Implementation Requirements: Reduce Inventory More
• Look for other areas
• Stores
• Transit
• Carousels
• Conveyors
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Lean Implementation Requirements: Improve Product Design
• Standard product configuration
• Standardize and reduce number
of parts
• Process design with product
design
• Quality expectations
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