title: On the preventive management of sediment-related sewer blockages: a combined maintenance and routing optimization approach.
abstract: In this work we tackle the problem of planning and scheduling preventive maintenance (PM) of sediment-related sewer blockages in a set of geographically distributed sites that are subject to non-deterministic failures. To solve the problem, we extend a combined maintenance and routing (CMR) optimization approach which is a procedure based on two components: (a) first a maintenance model is used to determine the optimal time to perform PM operations for each site and second (b) a mixed integer program-based split procedure is proposed to route a set of crews (e.g., sewer cleaners, vehicles equipped with winches or rods and dump trucks) in order to perform PM operations at a near-optimal minimum expected cost. We applied the proposed CMR optimization approach to two (out of five) operative zones in the city of Bogotá (Colombia), where more than 100 maintenance operations per zone must be scheduled on a weekly basis. Comparing the CMR against the current maintenance plan, we obtained more than 50% of cost savings in 90% of the sites.
authors.affiliation: Centro para la Optimización y Probabilidad Aplicada (COPA), Departamento de Ingeniería Industrial, Universidad de los Andes, Bogotá, Colombia.
authors.forename: John E
authors.initials: JE
authors.lastname: Fontecha
authors.affiliation: Centro para la Optimización y Probabilidad Aplicada (COPA), Departamento de Ingeniería Industrial, Universidad de los Andes, Bogotá, Colombia.
authors.forename: Raha
authors.initials: R
authors.lastname: Akhavan-Tabatabaei
authors.affiliation: Centro para la Optimización y Probabilidad Aplicada (COPA), Departamento de Ingeniería Industrial, Universidad de los Andes, Bogotá, Colombia.
authors.forename: Daniel
authors.initials: D
authors.lastname: Duque
authors.affiliation: Centro para la Optimización y Probabilidad Aplicada (COPA), Departamento de Ingeniería Industrial, Universidad de los Andes, Bogotá, Colombia.
authors.forename: Andrés L
authors.initials: AL
authors.lastname: Medaglia
authors.affiliation: Centro de Investigaciones en Ingeniería Ambiental (CIIA), Departamento de Ingeniería Civil y Ambiental, Universidad de los Andes, Bogotá, Colombia E-mail: pabl-rod@uniandes.edu.co.
authors.forename: María N
authors.initials: MN
authors.lastname: Torres
authors.affiliation: Centro de Investigaciones en Ingeniería Ambiental (CIIA), Departamento de Ingeniería Civil y Ambiental, Universidad de los Andes, Bogotá, Colombia E-mail: pabl-rod@uniandes.edu.co.
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Rodríguez
mesh_terms: D002947:Cities; D003105:Colombia; D019015:Geologic Sediments / Q000032:analysis*; D008962:Models, Theoretical; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*