Security Engineering
Wallace Hopp
Industrial Engineering Department
McCormick School of Engineering
A Flat World is an exciting but
dangerous world…
Technology
Advances
Opportunity
Reduced
Political Barriers
Risk
Global Business
Practices
Terrorism
Accidents in remote plants can have
large consequences for a supply chain…
Natural Disasters can disrupt business
around the globe…
Terrorism has a wider reach than ever
before…
A basic principle from Factory Physics is
central to security engineering
Buffering Principle: Systems with variability must be
buffered by some combination of:
1. inventory
2. capacity
3. time.
Buffer Flexibility Corollary: Flexibility reduces the
amount of variability buffering required in a production
system.
Strategies for dealing with risks depend
on likelihood and severity of event
Redundancy
High
Likelihood
of
Disruption
Contingency Planning
Do
Nothing
Crisis
Management
Low
Light
Severe
Consequences
Redundancy in a supply chain can be
either inventory or capacity
Suppliers
Subassembly
Manufacturer
Distributors
Customers
Safety
Stock
Supplier
Redundancy
Insight: usually
optimal to place
protection at a single
level in the supply
chain
Flexible buffers are more effective than
rigid ones
Full Flexibility
Chained Flexibility
Sub-Chained Flexibility
1
1
1
1
1
1
2
2
2
2
2
2
3
3
3
3
3
3
4
4
4
4
4
4
5
5
5
5
5
5
6
6
6
6
6
6
production plant
demand type
Supply chain disruptions can have both
tactical and strategic consequences
Philips
Nokia
Ericsson
Impact of a supply chain disruption on
sales revenue
Sales Revenue
Pre Event
Disruption
Event
Pent-Up
Sales
Short Term
Sales Loss
Time
Post Event
Market Share Loss
Impact of maintaining an inventory
buffer
Sales Revenue
Pre Event
Disruption
Event
Pent-Up
Sales
Time
Post Event
Impact of securing a backup capacity
supply
Sales Revenue
Pre Event
Disruption
Event
Pent-Up
Sales
Time
Post Event
Contingency Planning is one way to
prepare for risky events
Update
Anticipate
Plan
Prepare
Event
Execute
We can use network theory to measure
structural flexibility in organizations
Call Center
Agents
Queue of
Arriving Calls
Call Center
Agents
Queue of
Arriving Calls
Type A
1
Type A
Type B
2
Type B
2
The smaller the average path length
of the worksharing matrix, the more
robust the system is to routine
(I)
(II)
(III)
(IV)
variation and
Specialists
Zones exceptional
Chaining
Full
disruptions.
Type C
Type C
3
Type C
3
Type D
4
Queue of
Arriving Calls
1
Type B
2
Call Center
Agents
Type A
1
Type B
3
Queue of
Arriving Calls
Type A
1
2
Call Center
Agents
Type D
4
Type D
4
2
1
3
2
2
1
1
3
Type D
4
2
0.5
Type C
3
0.25
1
1
3
0.25
0.25
1
3
0.25
0.5
1
1
0.25
0.25
4
4
4
4
(I)
(II)
(III)
(IV)
Globalization, connectivity and complexity
are posing serious new security threats
Factory Physics and
Network Science
are useful tools in
the emerging field of
Security Engineering
Thank you on behalf of the
OPEM Research Group!
Taylan Ilhan
Vehicle
Routing
Rob Lien
Flexible Transshipment
Systems
Bilal Gokpinar
Innovative Team
Structure
Zigeng Yin
Robust Supply Chains
Yao Cheng
Crisis Management
Social
Networks
Operations
Mgmt
Wally Hopp
Seyed Iravani
www.opem.northwestern.edu
Fang Liu
Innovation Networks
Wendy Lu Xu
Terrorist Supply Chains
Jie Xu
Integrated Product and
Supply Chain Design
Bora Kofal
Flexibility in Production
and Service Systems
Gigi Yuen
White Collar Work
Systems