module 9: jit & lean systems operations management as a competitive weapon
TRANSCRIPT
Module 9:
JIT & Lean Systems
Operations Management as a Competitive Weapon
2Module 9: JIT & Lean Systems
OM Course Framework
TOC
JIT
MRP
Operational Issues
AggregatePlanning
Inventory
Location
Capacity
Tactical Issues
Manufacturing Design & Selection
Process Analysis
Operations Strategy
Strategic Issues
3Module 9: JIT & Lean Systems
Planning & Control Strategies
Flexibility (High)Unit Cost (High)
Flexibility (Low)Unit Cost (Low)
Flexibility (High)Unit Cost (High)
Flexibility (Low)Unit Cost (Low)
IV.Continuous Flow
III.Assembly Line
II.Batch
I.Job Shop
IV.Continuous Flow
III.Assembly Line
II.Batch
I.Job Shop
Factory Physics
TOCTOC
MRPMRP
J I TJ I T
LowVolume,One of aKind
MultipleProducts,LowVolume
HighVolume,HighStandard-ization
FewMajor
Products,HigherVolume
LowVolume,One of aKind
MultipleProducts,LowVolume
HighVolume,HighStandard-ization
FewMajor
Products,HigherVolume
Product
Process
Product
Process
4Module 9: JIT & Lean Systems
Learning Objectives
At the end of this module, each student will be able to:
1.Discuss Just-In-Time philosophy
2.Discuss JIT elements
3.Compare JIT and MRP
5Module 9: JIT & Lean Systems
1. APICS definition of JIT
A philosophy of manufacturing
based on waste elimination and
continuous improvement of
productivity.
6Module 9: JIT & Lean Systems
2. Primary Elements
A. Manufacturing have only the required inventory when
needed, reduce lead times by reducing setup times,
queue lengths, and lot sizes,
B. Total Quality Management improve quality to zero defects, incrementally revise the operations
themselves, and
Accomplish these activities at minimum cost.
7Module 9: JIT & Lean Systems
Inventory Hides Problems
Work in
process
queues
(banks)
Change
orders
Engineering design
redundancies
Vendor
delinquencies
Scrap
Design
backlogs
Machine
downtime
Decision
backlogsInspection
backlogs
Paperwork
backlog
Example: By identifying defective items from a vendor early in the production process the downstream work is saved.
Example: By identifying defective work by employees upstream, the downstream work is saved.
8Module 9: JIT & Lean Systems
Economic Order QuantityCOST
Total Cost
Q*
TC*
Optimal Order Quantity = =Q DSH
2
Q**
TC**
9Module 9: JIT & Lean Systems
Total Quality Management
Quality system involving entire organization from supplier to customer
Objective: Meet or exceed customer needs
through company-wide continuous improvement
Early proponents W. Edwards Deming - natural variability Philip B. Crosby - Quality is Free
10Module 9: JIT & Lean Systems
Deming: Natural variability
All process are subject to variability
Natural causes
Assignable causes
Objective: Identify assignable
causes
11Module 9: JIT & Lean Systems
Crosby: Quality is Free
ImprovedQuality
IncreasedProfits
Lower CostsProductivityRework/ScrapWarranty
Market GainsReputationVolumePrice
12Module 9: JIT & Lean Systems
3. Comparison
•MRP – Backward scheduling
•BOM
•Workcenter
•MRP schedule
13Module 9: JIT & Lean Systems
Comparison (cont.)
• JIT – Reduce lead time and WIP
•Repetitive manufacturing (assembly
line)
•Production level
•Products
•WIP
•Vendors
14Module 9: JIT & Lean Systems
Comparison (cont.)
Assembly Line Variable demand
Assembly Line Level demand
High Low
Long Short
Dimension MRP J I T
Where used
WI P
Cycle time
15Module 9: JIT & Lean Systems
Comparison (cont.)
Frozen Level
Terrible Balanced
Larger lot sizes Rejects
Balanced capacity No
rejects
Dimension MRP J I T
Sched. Flex.
Regard f or
capacity limits
Quality