An integer programming approach to a real-world recyclable waste collection problem in Argentina.

Area of Science:

• Operations Research
• Environmental Management
• Applied Mathematics

Background:

• Recyclable waste collection systems face routing inefficiencies.
• Manual route design in Morón, Argentina, resulted in unserviced areas.

Purpose of the Study:

• To optimize recyclable waste collection routes using mathematical programming.
• To develop an integer programming model for the generalized directed open rural postman problem.

Main Methods:

• Developed an integer programming model.
• Implemented a solving procedure with a subtour-merging algorithm.
• Incorporated subtour elimination constraints.

Main Results:

• Achieved 100% block coverage within the municipality by construction.
• Significantly outperformed previously used manually designed routes.
• Eliminated the issue of unserviced blocks, which affected up to 16% with manual routes.

Conclusions:

• Mathematical programming offers a superior solution for waste collection routing.
• The model-generated routes were adopted by the municipality in 2014.
• The methodology is being considered for national implementation in Argentina.