Next Generation Factory
Layouts
Saifallah Benjaafar, University of Minnesota
Shahrukh Irani, Ohio State University
Sunderesh Heragu, Rensselaer Polytechnic
Institute
Characteristics
 Flexible
 Modular
 Reconfigurable
 Agile
Needs
 High product variety
 Product demand volatility
 Low production volumes
 Short product lifecycles
Functional versus Cellular
Layouts
Functional layout
Cellular layout
Limitations of functional
layouts
 Material handling inefficiency
 Scheduling complexity
 Vulnerability to changes in product
mix/routings/volumes
 Prohibitive re-layout costs
Limitations of cellular
layouts
 Rapid obsolescence
 Workload unbalances
 Limited flexibility
 Resource duplication
Distributed Layouts
Functional layout
Partially distributed layout
Fully distributed layout
Advantages
 Effective hedging against future
fluctuation in product mix, volume and
routings
 Efficient material handling
 Flexible workload allocation
 Rapid formation of virtual cells
Design Procedure for
Distributed Layouts
Distribution of demand scenarios
Product process routings
Product unit transfer loads
Travel distances
Department
dis-aggregation
procedure
Flow allocation
procedure
Layout design
procedure
Modular Layouts
 Layouts are constructed as a network
of basic modules. Each module is a
group of machines in a portion of the
overall facility that has a flow pattern
characteristic of a traditional layout.
Motivation
 No single prevailing layout configurations
can individually describe the complex material
flow network in a multi-product manufacturing
facility.
 Modules can be added and removed as
needed.
 It captures the efficiency of each layout
configurations without the associated
limitations.
Layout Modules
C
A
B
C
D
E
A
D
B
(a) Flowline Module
G
E
F
(b) Branched Flowline Module
C
B
D
A
E
A+B+C
(d) Machining Center Module
(c) Cell Module
B
C
B
D
C
E
D
A
A
(e)
E
Functional Layout Module
(f) Patterned Flow Module
H
Example Modular Layout
Functional Layout for ETCH
Flowline for ETCH
2.06
2.08
2.09
2.10
2.07
Flowline for PHOTO
2.01
5.01
5.02
5.03
5.04
5.05
5.06
7.03
7.02
7.01
3.08
7.04
7.05
3.04
3.07
5.07
Functional Layout for
FILM Department
2.05
6.01
3.01 3.02
5.02
3.04 3.05
3.06
5.03
5.04
Flowline for BACKEND
5.05
2.02
4.01
1.03
1.04
1.02
1.01
1.05
Cell for ETCH, IMPLANT and PHOTO
Functional Layout for
ETCH, FILM and PHOTO
Flowlines for DIFF
String Matching-Based Design
Procedure
Identify predominant
product routings
Module selection
and layout design
Extract common
sub-strings
Aggregate common
sub-strings and form
preliminary modules
Reconfigurable Layouts
 Layouts are physically reconfigured
(by moving resources and
reconfiguring the material handling
system) on short notice due to change
in product mix or production volumes.
Motivation
 In many industries, fabrication and assembly
workstations are light and can be easily
relocated.
 Newer processing technologies permit light
weight equipment.
 Light weight equipment could be mounted on
wheels and easily moved along suitably designed
tracks embedded in the shop-floor.
As a result, a layout could be changed
several time a year!
Re-Layout Design Procedure
Design Data
+ New Product Design
+ New Processes Selected
Production Data
+ Changed Product Mix
+ Expected Volume
Material Handling Costs
Revised Material Flow Matrices / Adjacency Matrices
Current Facility Layout
Relocation Costs
Facility Layout Design
Output
+ Machine Locations
+ Material Flow Plan
Agile Layouts
 Layouts are designed with
agility-based criteria, such as cycle
time, work-in-process, and
production throughput.
A Queueing-Based Layout
Design Procedure
Material handling
system
Processing departments
2
Full trip from the origin of current request
to its destination department
1
3
Empty trip from destination of previous
delivery to origin of current request
4
Input buffer
Output buffer
Queueing Effects
Congestion is affected by:
 travel distances (empty and full travel)
 travel distance variability
 number and capacity of material handling
devices
 dispatching policies
 processing time distributions
 utilization of processing departments
Queueing Effects
 Reducing full travel does not always improve
performance.
 Full travel- optimal layouts can be
congestion-infeasible.
 Congestion is affected by both the mean and
variance of travel times.
 Congestion is affected by non-material
handling factors.
Summary
Although most factories of the future
will need customized layout solutions,
the produced layouts must be robust,
adaptable, and agile. This project is
exploring novel ways of achieving this
goal.