LeMur Scheduler: An Innovative Approach to Spiral Binding Planning
Winner of the Industrial AI Challenge 2025 @ UniTN
🌀 LeMur Scheduler: An Innovative Approach to Spiral Binding Planning
Welcome to the project page of Team 3 - LeMur, part of the Industrial AI Challenge! Our mission? To revolutionize the way LeMur schedules production in its spiral binding department through intelligent automation and optimization.
📚 Project Resources & Demo
🔍 The Challenge
Efficient workforce scheduling and workload management are critical for any modern manufacturing process. LeMur sought a system that could generate optimized production plans, balancing workload distribution while respecting the unique constraints of their spiral binding operations—where manual interventions and asynchronous machine operations add complexity.
🎯 Project Goals
We set out to design a smart scheduler capable of:
- Suggesting optimal machine and operator schedules.
- Ensuring a balanced distribution of manual tasks.
- Delivering scalable and flexible planning over an extended time horizon—going beyond the company’s current day-by-day planning approach.
🧠 Problem Definition
To build an effective solution, we first developed a deep understanding of LeMur’s internal processes, defining key concepts like:
- Articles (products),
- Cycles (Setup, Load, Running, Unload, Machine Waiting),
- Operators and their roles.
We identified hard constraints (e.g., max simultaneous manual operations) and incorporated company-specific logic such as active/inactive cycles, partial/complete cycles, and machine capacity variations.
🛠 Methodology & Tools
The core scheduling problem falls under the Job Shop Problem (JSP) category, which is computationally complex. We chose a hybrid approach combining:
- ✅ Constraint Programming (for solution correctness and expressiveness),
- 🔁 Genetic Algorithms (for refinement and computational scalability).
We used:
- Google OR-Tools for CP modeling and solving,
- Inspyred for the genetic refinement phase.
Our 3-stage optimization pipeline:
- Makespan Minimization
- Compactness Maximization
- Genetic Refinement
📊 Data & Synthetic Generation
Although historical data wasn’t used directly for learning, it helped us understand production patterns and design a synthetic dataset generator for testing. Input data includes:
- CSV files with ongoing and new orders,
- JSON files specifying articles and machine capabilities.
🗓 Weekly Development Process
Over several weeks, we followed a structured development cycle involving:
- Process analysis,
- Constraint formulation,
- Solver implementation,
- Continuous testing and validation,
with regular feedback from LeMur’s mentors and domain experts.
✅ Results & Evaluation
Our hybrid solver delivers:
- Valid schedules within short computation times, even on complex scenarios.
- Progressive improvements through optimization stages.
- A strong match between generated and ideal workloads, often outperforming LeMur’s current planning system in terms of balance and load distribution.
⚙️ Performance Highlights
- Quick generation of first valid solutions
- Scalable on more powerful hardware
- Balanced operator workloads, minimizing bottlenecks and overloads
📊 Real-world Comparison
Tests showed our scheduler better reflects actual workload realities, highlighting areas where the current planning might underestimate operational demands.
🌐 Integrations & Tools
To make the system user-friendly and practical:
- A local web app was built for input management and Gantt chart visualization.
- A data converter was created to seamlessly interface with LeMur’s current planning formats.
🏭 Impact & Future Directions
The system paves the way for:
- Higher operational efficiency
- Better long-term planning
- Healthier workloads and improved work environments
Proposed future enhancements include:
- “Ghost production” suggestions based on demand forecasting
- Energy consumption and machine speed optimization
- Integration with LeMur’s ERP for full automation
💡 Conclusion
Team 3 proudly delivered a cutting-edge scheduling system tailored for LeMur’s spiral binding department. By combining Constraint Programming with Genetic Algorithms, we created a scalable, intelligent, and flexible solution. Validated by LeMur themselves, this tool stands to transform their production planning and workforce management for the better.