Technical Overview

XLOptim was a specialized optimization add-on for Excel, developed by XLSTAT (later acquired by Lumivero) as a proof of concept that leveraged LocalSolver(Hexaly)’s powerful local search optimization engine.

Core Technology: C++ to VBA Wrapper

Technical Architecture

Wrapper Technology

  • Language Bridge: Custom C++ to VBA wrapper
  • Purpose: Enable seamless integration of LocalSolver’s C++ optimization engine with Excel’s VBA environment
  • Key Components:
    • C++ Dynamic Link Library (DLL)
    • VBA Interface Module
    • Memory Management Layer
    • Optimization Algorithm Translations

Wrapper Functionality

  • Data Translation: Convert Excel cell ranges to C++ data structures
  • Optimization Engine Calls: Translate VBA parameters to mathematical model
  • Result Propagation: Return optimization results back to Excel spreadsheets
  • Error Handling: Robust error management between C++ and VBA contexts

Optimization Approach

LocalSolver Integration

  • Search Strategy: Local search metaheuristics
  • Optimization Types:
    • Continuous optimization
    • Discrete optimization
    • Mixed-integer optimization

Excel Add-On Capabilities

  • Direct optimization within Excel spreadsheets
  • Support for complex constraint modeling
  • Rapid solving of optimization problems
  • Seamless integration with existing Excel workflows

Development Context

  • Creator: XLSTAT Research Team
  • Technological Foundation: LocalSolver’s optimization engine
  • Acquisition: Integrated into Lumivero’s product portfolio

Technical Challenges Solved

  1. Bridging C++ high-performance computing with Excel’s VBA
  2. Translating complex mathematical models across language boundaries
  3. Maintaining performance while providing user-friendly interface
  4. Robust error handling in mixed-language environment

Wrapper Technical Challenges

  • Memory Management: Preventing memory leaks
  • Data Type Conversion: Handling numerical precision
  • Performance Optimization: Minimizing overhead
  • Error Propagation: Consistent error reporting

Use Cases

  • Financial modeling
  • Resource allocation
  • Production planning
  • Portfolio optimization
  • Scheduling problems