Package org.ddolib.examples.msct

Class MSCTLnsMain

java.lang.Object

org.ddolib.examples.msct.MSCTLnsMain

public class MSCTLnsMain
extends Object

Entry point for solving the Minimum Sum of Completion Times (MSCT) problem using a Large Neighborhood Search (LNS) approach combined with Decision Diagram Optimization (DDO).

The Minimum Sum of Completion Times problem consists in scheduling a set of jobs on a single machine so as to minimize the sum of their completion times. Each job has a processing time, and the objective is to determine an execution order that minimizes the total completion cost.

This class demonstrates how to:

• Load an MSCT instance from a file
• Define a LnsModel with problem-specific components
• Use a lower bound heuristic to guide the search
• Apply dominance rules to prune suboptimal schedules
• Control the decision diagram width
• Run a Large Neighborhood Search (LNS) optimization
• Print intermediate and final solutions

Execution

The program accepts an optional command-line argument specifying the path to an MSCT instance file. If not provided, a default instance is loaded from:

 data/MSCT/msct1.txt
 

Model Components

• MSCTProblem – defines the scheduling instance
• MSCTFastLowerBound – provides a fast lower bound on the objective
• MSCTDominance – defines dominance relations between partial schedules
• SimpleDominanceChecker – applies dominance pruning
• MSCTRanking – ranks states during decision diagram compilation
• FixedWidth – limits the decision diagram width

Search Configuration

• Search strategy: Large Neighborhood Search (LNS)
• Time limit: 100 milliseconds
• Width heuristic: fixed width of 10 nodes per layer

Output

The program prints:

• Intermediate solutions during the search
• Final solution statistics
• The best job sequence found

See Also:

• MSCTProblem
• MSCTState
• MSCTFastLowerBound
• MSCTDominance
• MSCTRanking
• LnsModel
• Solvers.minimizeLns(org.ddolib.modeling.LnsModel<T>, java.util.function.Predicate<org.ddolib.common.solver.SearchStatistics>, java.util.function.BiConsumer<int[], org.ddolib.common.solver.SearchStatistics>)
• Solution

Constructor Summary

Constructors

Constructor	Description
MSCTLnsMain()

Method Summary

Modifier and Type	Method	Description
static void	main(String[] args)	Main entry point of the program.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

MSCTLnsMain

public MSCTLnsMain()

Method Details

main

public static void main(String[] args)
                 throws IOException

Main entry point of the program.

Loads an MSCT instance, configures the LNS model with problem-specific heuristics and dominance rules, and runs the optimization process.

Parameters:

args - optional command-line arguments:

• args[0] – path to the MSCT instance file

Throws:

IOException - if the instance file cannot be read