New release: Hexaly 11.5

Announcement

Frédéric, Ph.D. Senior Optimization Scientist November 7, 2022

We are pleased to announce the release of Hexaly 11.5. Discover below the main novelties coming with this new release.

Vehicle Routing problems

Vehicle Routing problems are solved even faster. The “gap” mentioned below is the relative gap in % between the solutions computed by Hexaly 11.5 within 1 minute of running time on a standard server (Intel Core i7-7700K processor, 4 cores, 4.2 GHz, 8MB cache, 64GB RAM) and the best-known solutions available in the research literature (computed using dedicated algorithms, within arbitrary long running times, and possibly taking advantage of more powerful hardware).

• Capacitated Vehicle Routing Problem (CVRP): average gap of 1.3% for instances with up to 1,000 deliveries.
• Capacitated Vehicle Routing Problem with Time Windows (CVRPTW): average gap of 2.9% for instances with up to 1,000 deliveries.
• Pickup and Delivery Problem with Time Windows (PDPTW): average gap of 2.4% for instances with up to 1,000 deliveries.
• Capacitated Arc Routing Problem (CARP): average gap of 0.7% for instances with up to 350 arcs to visit.

Hexaly 11.5 improves its lower bounds for the Vehicle Routing Problem with Time Windows (CVRPTW) with an average dual gap of 9% for instances with up to 100 deliveries within 1 minute of running time.

Production Scheduling problems

The “gap” mentioned below is computed in the same way as above. In particular, Hexaly 11.5 is launched with a time limit of 1 minute only.

• Job Shop Scheduling Problem: average gap of 2.2% for instances with up to 2,000 tasks.
• Flexible Job Shop Scheduling Problem: average gap of 0.3% for instances with up to 500 tasks.
• Flexible Job Shop Scheduling Problem with Sequence-Dependent Setup Times: average gap of 0.4% for instances with up to 400 tasks.
• Resource Constrained Project Scheduling Problem (RCPSP): average gap of 1.4% for instances with up 300 tasks.
• Scheduling Problem with Calendar Constraints: average gap of 2.3% for instances with up 500 tasks.

Global optimization capabilities

• Mixed-Integer Nonlinear optimization (MINLP): optimal solutions found in less than 1 minute of running time for 734 instances over the 1,668 in the MINLPLib benchmark (+38 instances compared to LocalSolver 11.0, +94 instances compared to Hexaly 10.5). Note that Hexaly checks constraint feasibility with a relative 1e-6 numerical precision and objective optimality with a relative 1e-4 numerical precision.

Simulation optimization capabilities

• Constrained black-box optimization: 100% of feasible solutions and 77% of optimal solutions found with an average of 50 black-box evaluations in 5 runs over 36 instances from the research literature, compared to 87% (resp. 82%) of feasible solutions and 31% (resp. 21%) of optimal solutions found with an average of 112 (resp. 124) black-box evaluations for RBFOpt (resp. NOMAD) black-box optimization solver.

Modeling APIs and language (LSP)

• Modeling your business problems is made easier with the Contains operator for set and list decisions. For example, look at the Hexaly model for the Capacitated Arc Routing Problem (CARP).
• CSV file parsing is available in the standard LSP library.

use csv;

function input() {
    data = csv.parse("./data.csv");
    for [row in data.rows] {
        //...   
    }
}

• Hexaly modeling language (LSP) can be used as a plain programming language with the addition of a main function.

function main() {
    readData();
    solveSubProblem1();
    solveSubProblem2();
    writeSolution(solution);
}

Hexaly Studio

This new version comes with a new product: Hexaly Studio. Hexaly Studio allows you to develop and test Hexaly-powered optimization applications anywhere from your browser. On a single interface, you benefit from:

• An online disk space to import and share your data;
• An editor to write, launch, and debug your Hexaly optimization models by taking advantage of the power of Hexaly Cloud;
• An interactive dashboard to bring your Hexaly optimization models to life in the form of KPIs, maps, Gantt charts, and other various GUI widgets.

New code examples

New code examples are available in the Example Tour to help you get started quickly with Hexaly :

We are at your disposal to accompany you in the discovery of Hexaly 11.5. Please ask for your free trial license by registering here. In the meantime, don’t hesitate to contact us for further information or support.