Lab #4: Pull and Perfection
MG/IE 3400 – Production System Design
The New Scenario …
Products:



Blue sapphire
Black diamond
Grey pearl
2/minute
2/minute
1/minute
Customers want clocks delivered in less
than 1 minute
Pull Production
Information Flow
OUT
OUT
OUT
Work
Center
Work
Center
Work
Center
A
B
C
IN
IN
Material Flow
Warehouse
IN
Number of Kanbans
k = # kanbans/signals (here, c=1)
d = demand per unit time
L = lead time
a = safety factor
k= dL(1+a)
Little’s Law
L=lW
Process ‘law’:


WIP = production rate x lead time
‘steady-state’ performance
TimeWise
What determines the production rate?
Session
Morning
Afternoon
1
2
3
1
2
3
WIP
Actual Lead
Time (min)
20
88
82
60
84
32
9
>15
>15
>15
>15
11, 14
Little's Law
Back/Hand Assembly
Blue
Blue
Black
Black
Visual
Layout
How to
Accomplish Lean
7. Improve Product Design:

Standard product configuration

Standardize and reduce number of
parts

Process design with product design

Quality expectations
1.
Design Flow Process

Link operations

Balance workstations capacity

Redesign layout for flow

Emphasize preventive maintenance

Reduce lot sizes

Reduce setup/changeover time
2. Total Quality Control:
Concurrently
Solve Problems:
Root cause
Solve permanently
6. Reduce Inventory More:

Look for other areas

Stores

Transit

Carousels

Conveyors
Team approach

Worker responsibility

Measure: SQC

Enforce compliance

Fail-safe methods

Automatic inspection
Line and specialist responsibility
Continual education
3. Stabilize Schedule:
Measure Performance:

Level schedule
Emphasize Improvement

Underutilize capacity
Track trends

Establish freeze windows
5. Work with Vendors:

Reduce lead times

Frequent deliveries

Project usage requirements

Quality expectations
4. Kanban Pull:

Demand pull

Backflush

Reduce lot sizes