Originally posted by: Dmartinc

Hi all,

I am starting with CP due to I would like to code a crew scheduling model, which I´ve already solved with Cplex using C++ and compare their computational results. After having solved several simple models I am on a deadlock.

My main issue right now are the disjunctive constraints or unary (disjunctive) resources. Those of this kind:

-Unary capacity of the resource: Cap(A)=1, meaning this that activities cannot be overlapped.
-Any two non-preemptive activites are related by the disjunctive constraint A<<B or B<<A

Being this example the starting point which will open many doors:

• One machine with jobs running on it,being this the constraint:

Constraint: Cumulative(http://task(Start(A),P(A),End(A),1, A),...,task(Start(An),P(An),End(An),1, An), Options)

A..An: Activity identifiers
Start(A): Start time of the activity
P(A): Processing time
End(A): Completation time of the activity
Options: options for different propagation algorithms
4th parameter of the task =1: unit consumption of the resource

I would appreciate any hint or literature references on how to code this in Ilog CP using C++.

Cheers,

David
#CPOptimizer
#DecisionOptimization

Originally posted by: SystemAdmin

Hello David.

CP Optimizer supports disjunctive and cumulative resources in a completely different way. Instead of integer variables there are interval variables (IloIntervalVar), disjunctive resource is modeled using noOverlap constraint (IloNoOverlap) and cumulative resource is modeled using cumulative function (IloCumulFunctionExpr).

I recommend you to have a look into the documentation. Here are few possible starting points (links to online copy of the documentation):
http://pic.dhe.ibm.com/infocenter/cosinfoc/v12r4/index.jsp?topic=%2Filog.odms.cpo.help%2Frefcppcpoptimizer%2Fhtml%2Fintroduction.html
http://pic.dhe.ibm.com/infocenter/cosinfoc/v12r4/index.jsp?topic=%2Filog.odms.cpo.help%2FCP_Optimizer%2FGetting_started%2Ftopics%2Fschedseq.html
http://pic.dhe.ibm.com/infocenter/cosinfoc/v12r4/index.jsp?topic=%2Filog.odms.cpo.help%2FCP_Optimizer%2FUser_manual%2Ftopics%2Fdesignsched.html

You can also have a look on C++ delivered examples, you can find them in directory cpoptimizer/examples/src/cpp. Scheduling examples start with sched_. You can find noOverlap constraint for example in sched_jobshop.cpp.

I hope it helps, Petr
#CPOptimizer
#DecisionOptimization

Originally posted by: Dmartinc

Cheers Petr
#CPOptimizer
#DecisionOptimization