constraint programming for supply chain management
DESCRIPTION
SCM Information Day, Nov. 21/02. Constraint Programming for Supply Chain Management. J. Christopher Beck Cork Constraint Computation Centre (4C) [email protected]. Outline. What is Constraint Computation? aka Constraint Programming (CP) - PowerPoint PPT PresentationTRANSCRIPT
Constraint Programming for Constraint Programming for Supply Chain ManagementSupply Chain Management
J. Christopher BeckCork Constraint Computation Centre (4C)
SCM Information Day, Nov. 21/02
2
OutlineOutline
What is Constraint Computation?– aka Constraint Programming (CP)
What does constraint computation have to do with supply chain management?
3
A PuzzleA Puzzle
Place the numbers 1 through 8 in the nodes such that:– Each number appears exactly once
?
?
?
?
?
?
??
– No connected nodes have consecutive numbers
You have 5 minutes!
4
ModelingModeling
Each node a variable{1, …, 8} values in the domain of each
variableNo consecutive numbers a constraint
– (vi, vj) |vi – vj| > 1
All values used all-different constraint
5
Heuristic SearchHeuristic Search
?
?
?
?
?
?
?? 1 8
{1, 2, 3, 4, 5, 6, 7, 8}
6
Inference/PropagationInference/Propagation
?
?
?
?
?
?
?? 1 8
{1, 2, 3, 4, 5, 6, 7, 8}
{1, 2, 3, 4, 5, 6, 7, 8}
7
Inference/PropagationInference/Propagation
?
?
?
?
?
?
?? 1 8
{3, 4, 5, 6}
7 2
{3, 4, 5, 6}
{3, 4, 5, 6} {3, 4, 5, 6}
64
3 5
{3, 4, 5, 6, 7} {2, 3, 4, 5, 6}
8
The Core of Constraint ComputationThe Core of Constraint Computation
Modeling– What should the variables/domains/constraints
be?Heuristic Search
– Quality vs. complexity trade-offInference/Propagation
– How much effort should be spent on inference?
Focus of 4C: Automating the process of constraint modeling and solution strategy configuration
9
OutlineOutline
What is Constraint Computation?What does constraint computation have to
do with SCM?
10
A Commercial RealityA Commercial Reality
First-tier software vendors embed CP technology in their SCM software
This is not to imply that SCM is a “solved”
problem
Nor that CP is (just) a matter of
engineering
11
CP & SCMCP & SCM
The puzzle is actually a hard problem– NP-complete
Can apply the same technology to core SCM problems– Vehicle routing– Scheduling– Warehouse location
12
Example: Vehicle RoutingExample: Vehicle Routing
Depot
10
10
15
[10 20][15 15]
[10 20][25 20]
13
Example: Vehicle RoutingExample: Vehicle Routing
Depot
10
10
15
[10 20]
[10 20]
[20 20]
[10 10]
14
SCM is DistributedSCM is Distributed
15
Distributed Problem SolvingDistributed Problem Solving
SCM cannot be solved centrally– Problem size, authority, corporate structure
Distributed problem solving is key
– Sub-problems are still important (and hard!)
16
SCM-related Research at 4CSCM-related Research at 4C
Scheduling & vehicle routingDistributed scheduling Negotiation & privacySoft constraints & preferences
Focus on reducing the cognitive load for using existing technology
17
Research at 4C: Extending SCMResearch at 4C: Extending SCM
Concurrent engineering– Extend the supply chain to design phase
On-line configuration– Bring the individual into the supply chain
Dealing with uncertainty– The course of true SCM never did run smooth
18
Take Home MessageTake Home Message
CP is a commercial reality in SCMInsight into the core of CP technology4C is pushing the bounds of CP
– Automation of hard parts of using CP– Application of CP to new problems
4C is interested is SCM– Application for on-going research– New opportunities
19
Director: Professor Gene Freuder
E-mail: [email protected]
External Liaison Officer: Dr. James Little
Phone: +353-(0)21-4255410
E-mail: [email protected]
Post: 4C, UCC, Cork, Irelandwww.4c.ucc.ie
4C - Contact Information4C - Contact Information