SCC-VRP Instance Sets Description
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This document describes the three groups of instances used in the Shared Customer Collaboration Vehicle Routing Problem (SCC-VRP). 
Each group follows different generation criteria and is based on prior work from the literature.

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Set S1
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The S1 set consists of 12 instances derived from the multi-depot vehicle routing problem (MDVRP) instances proposed by Cordeau, Gendreau, and Laporte [9].

- Number of clients: between 18 and 30.
- Number of carriers: 2.
- Shared customers: randomly assigned with a probability of 0.25.
- Purpose: provides small- to medium-sized instances originally adapted for the SCC-VRP framework.

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Set S2
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The S2 set was generated in the work of Fernández, Roca-Riu, and Speranza [1]. 
It is divided into two subsets: S2_R (random) and S2_C (clustered). Each subset contains 50 instances.

Both subsets share the following features:
- Number of carriers: 2.
- Depot locations: (0, 0) and (100, 100).
- Shared customer probability: 0.25.

Differences between subsets:
- **S2_R (Random):** customers are uniformly distributed within a 100x100 square.
- **S2_C (Clustered):** customers are grouped into clusters within the same 100x100 area.

Each subset includes 10 instances for each customer size |N| = {10, 15, 20, 25, 30}.

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Set S3
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The S3 set was created in this work following the instance generation criteria described by Felipe Torres-Ramos et al. [4]. 
The original S3 instances were not publicly available, so new instances were generated accordingly.

Main characteristics:
- Number of instances: 12 (3 for each customer size).
- Customer sizes: |N| = {90, 180, 270, 360}.
- Vehicle capacities: 100, 250, and 400 (one for each instance of the same size).
- Customer demands: uniformly distributed in the range (5, 25).
- Percentage of shared customers: 20% of the total.
- Number of carriers: 2.

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References
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[1] Elena Fernández, Mireia Roca-Riu, and M. Grazia Speranza. "The Shared Customer Collaboration Vehicle Routing Problem". 
    European Journal of Operational Research 265.3 (2018): 1078–1093. doi: 10.1016/j.ejor.2017.08.051.

[4] A. Felipe Torres-Ramos et al. "A GRASPxILS for the Shared Customer Collaboration Vehicle Routing Problem". 
    IFAC PapersOnLine 52-13 (2019): 2608–2613. doi: 10.1016/j.ifacol.2019.11.600.

[9] Jean-François Cordeau, Michel Gendreau, and Gilbert Laporte. 
    "A tabu search heuristic for periodic and multi-depot vehicle routing problems". 
    Networks 30 (1997): 105–119.
