Strategic planning and transport optimization algorithms

Predmet istraživanja doktorske disertacije su algoritmi za planiranje i optimizaciju transporta. Ciljevi rada su konstrukcija, testiranje i analiza predloženih algoritama. Razmatrana su tri problema planiranja transporta, problemi taktičkog planiranja, strateškog planiranja i strateško-taktičkog planiranja i sinhronizacije sa proizvodnjom, kao i jedan problem generisanja matrica rastojanja. Za svaki problem implementiran je algoritam, definisani test primeri, metodologija testiranja, analizirani rezultati, izvedeni zaključci i navedeni pravci za poboljšanja i dalja istraživanja. Za potrebe rešavanja problema taktičkog planiranja definisana je posebna struktura bazirana na stablima, algoritam odabiranja satelita i ciljna funkcija. Algoritam za strateško planiranje koristi strukturu kružne liste za kodiranje lokacija i vozila i generičku transformaciju. Modelirana je dinamika hlađenja za algoritam Simuliranog kaljenja u skladu sa veličinom test primera. Za strateško-taktički problem planiranja i sinhronizaciju sa proizvodnjom odabran je problem distribucije novina u Danskoj. Data je definicija problema, predloženi su model, struktura bazirana na stablima i transformacije. Definisano je dekodiranje plana transporta kao i način raspoređivanja novina na vozila. Za potrebe generisanja matrica rastojanja konstruisan je Algoritam konusa koji putem internet servisa preuzima deo putne mreže dok se preostala rastojanja potrebna za matricu preračunavaju uz pomoć Dijkstra algoritma. Rezultati testiranja algoritma taktičkog planiranja pokazali su da je moguće efikasno automatski odabirati pozicije satelita i ostariti uštedu u ukupnim troškovima. Kružna struktura i generička transformacija u algoritmu za strateško planiranje dali su rezultate koji su uporedivi sa najboljim rezultatima dostupnim u literaturi. Algoritam za strateško-taktičko planiranje i sinhronizaciju sa proizvodnjom uspeo je da pronađe nekoliko najboljih rešenja na test primerima iz literature i ostvari uštedu od 15% do 25% na realnim problemima iz prakse. Matrice generisane Dijsktra algoritmom iz rastojanja dobijenih primenom Algoritma konusa sadrže oko 50% optimalnih vremenskih i oko 80% optimalnih prostornih rastojanja. Testovi su pokazali da primena ovih matrica u softveru za optimizaciju daju rešenja istog kvaliteta kao i matrice dobijene preuzimanjem svih rastojanja grubom silom. Svi algoritmi implementirani su i koriste se u softverskim paketima u praksi.The subject of the doctoral dissertation research is algorithms for transport planning and optimization. The objectives of the work are the construction, testing, and analysis of the proposed algorithms. Three problems of transport planning, problems of tactical planning, strategic planning, and strategic-tactical planning and synchronization with the production were considered, as well as one problem of generating distance matrices. For each problem, an algorithm was implemented, test examples and testing methodology were defined, results, conclusions, and directions for improvements and further research were stated. For the purpose of solving the problem of tactical planning, a special structure based on trees, a satellite selection algorithm, and a target function have been defined. The strategic planning algorithm uses a circular list structure for coding locations and vehicles, and generic transformation. The cooling schedule for the Simulated Annealing algorithm is modeled. The problem of newspaper distribution in Denmark was chosen for the strategic-tactical problem of planning and synchronization with production. The definition of the problem is given, the model is proposed, a structure based on trees, and transformations are presented. The decoding of the transport plan has been defined, as well as the manner of distributing newspapers on vehicles. For the purpose of generating distance matrices, a Cone Algorithm was constructed, which downloads a part of the road network via an Internet service, while the remaining distances required for the matrix are recalculated with the help of the Dijkstra algorithm. The results of testing the tactical planning algorithm have shown that it is possible to efficiently automatically select satellite positions and make savings in total costs. The circular structure and generic transformation in the strategic planning algorithm yielded results that are comparable to the best results available in the literature. The algorithm for strategic-tactical planning and synchronization with production managed to find some of the best solutions on test examples from the literature and achieved savings of 15% to 25% on real problems from practice. Matrices generated using the Dijkstra algorithm from distances obtained using the Cone Algorithm contain about 50% of the optimal time and about 80% of optimal spatial distances. Tests have shown that the application of these matrices in optimization software gives solutions of the same quality as matrices obtained by getting all distances by brute force. All algorithms are implemented and used in software packages in practice

Strategic planning and transport optimization algorithms

Predmet istraživanja doktorske disertacije su algoritmi za planiranje i optimizaciju transporta. Ciljevi rada su konstrukcija, testiranje i analiza predloženih algoritama. Razmatrana su tri problema planiranja transporta, problemi taktičkog planiranja, strateškog planiranja i strateško-taktičkog planiranja i sinhronizacije sa proizvodnjom, kao i jedan problem generisanja matrica rastojanja. Za svaki problem implementiran je algoritam, definisani test primeri, metodologija testiranja, analizirani rezultati, izvedeni zaključci i navedeni pravci za poboljšanja i dalja istraživanja. Za potrebe rešavanja problema taktičkog planiranja definisana je posebna struktura bazirana na stablima, algoritam odabiranja satelita i ciljna funkcija. Algoritam za strateško planiranje koristi strukturu kružne liste za kodiranje lokacija i vozila i generičku transformaciju. Modelirana je dinamika hlađenja za algoritam Simuliranog kaljenja u skladu sa veličinom test primera. Za strateško-taktički problem planiranja i sinhronizaciju sa proizvodnjom odabran je problem distribucije novina u Danskoj. Data je definicija problema, predloženi su model, struktura bazirana na stablima i transformacije. Definisano je dekodiranje plana transporta kao i način raspoređivanja novina na vozila. Za potrebe generisanja matrica rastojanja konstruisan je Algoritam konusa koji putem internet servisa preuzima deo putne mreže dok se preostala rastojanja potrebna za matricu preračunavaju uz pomoć Dijkstra algoritma. Rezultati testiranja algoritma taktičkog planiranja pokazali su da je moguće efikasno automatski odabirati pozicije satelita i ostariti uštedu u ukupnim troškovima. Kružna struktura i generička transformacija u algoritmu za strateško planiranje dali su rezultate koji su uporedivi sa najboljim rezultatima dostupnim u literaturi. Algoritam za strateško-taktičko planiranje i sinhronizaciju sa proizvodnjom uspeo je da pronađe nekoliko najboljih rešenja na test primerima iz literature i ostvari uštedu od 15% do 25% na realnim problemima iz prakse. Matrice generisane Dijsktra algoritmom iz rastojanja dobijenih primenom Algoritma konusa sadrže oko 50% optimalnih vremenskih i oko 80% optimalnih prostornih rastojanja. Testovi su pokazali da primena ovih matrica u softveru za optimizaciju daju rešenja istog kvaliteta kao i matrice dobijene preuzimanjem svih rastojanja grubom silom. Svi algoritmi implementirani su i koriste se u softverskim paketima u praksi.The subject of the doctoral dissertation research is algorithms for transport planning and optimization. The objectives of the work are the construction, testing, and analysis of the proposed algorithms. Three problems of transport planning, problems of tactical planning, strategic planning, and strategic-tactical planning and synchronization with the production were considered, as well as one problem of generating distance matrices. For each problem, an algorithm was implemented, test examples and testing methodology were defined, results, conclusions, and directions for improvements and further research were stated. For the purpose of solving the problem of tactical planning, a special structure based on trees, a satellite selection algorithm, and a target function have been defined. The strategic planning algorithm uses a circular list structure for coding locations and vehicles, and generic transformation. The cooling schedule for the Simulated Annealing algorithm is modeled. The problem of newspaper distribution in Denmark was chosen for the strategic-tactical problem of planning and synchronization with production. The definition of the problem is given, the model is proposed, a structure based on trees, and transformations are presented. The decoding of the transport plan has been defined, as well as the manner of distributing newspapers on vehicles. For the purpose of generating distance matrices, a Cone Algorithm was constructed, which downloads a part of the road network via an Internet service, while the remaining distances required for the matrix are recalculated with the help of the Dijkstra algorithm. The results of testing the tactical planning algorithm have shown that it is possible to efficiently automatically select satellite positions and make savings in total costs. The circular structure and generic transformation in the strategic planning algorithm yielded results that are comparable to the best results available in the literature. The algorithm for strategic-tactical planning and synchronization with production managed to find some of the best solutions on test examples from the literature and achieved savings of 15% to 25% on real problems from practice. Matrices generated using the Dijkstra algorithm from distances obtained using the Cone Algorithm contain about 50% of the optimal time and about 80% of optimal spatial distances. Tests have shown that the application of these matrices in optimization software gives solutions of the same quality as matrices obtained by getting all distances by brute force. All algorithms are implemented and used in software packages in practice

Vehicle scheduling in a harvest season

The collection of agricultural goods is a very dynamic process which involves the coordination of hundreds of transport routes and machines with respect the processing capacities at a factory. Numerous fluctuations in the number of transport vehicles, malfunctioning on engaged machines and weather conditions make the process of planning and maximizing the utilization of all resources very difficult. In this paper we present a mathematical model and a heuristic algorithm that in a short period of time finds nearly optimal solutions, which enables a dispatcher to re-plan and update the collection plan according to new constraints

Configuración de una red de distribución física para un operador logístico en Bogotá

Trabajo de InvestigaciónSe presenta un estado del arte acerca de la configuración de redes con especial enfacis en las opciones que se encuentran en la literatura para la estructura de la red y la localización de instalaciones en los distintos nodos de la red para llevar a cabo la distribución de mercancias por parte de un operador logístico de la ciudad de Bogotá. Además, la documentacion de un modelo realizado en el semillero de investigación SILOS de la Universidad Católica de Colombia, tomando como referente autores de la literatura. Finalmente se propone un método para contribuir a la toma de decisión en al apertura de instalaciones logísticas en la red de distribución y se anexa preguntas planteadas como apoyo en la puntuación de los criterios y alternativas que se evaluen con apoyo del métodoINTRODUCCIÓN 1. GENERALIDADES 2. CONFIGURACIÓN DE REDES 3. DOCUMENTACIÓN DEL MODELO MATEMÁTICO 4. PROPUESTA USO DE MÉTODO AHP PARA LOCALIZACIÓN CONCLUSIONES RECOMENDACIONES BIBLIOGRAFÍA ANEXOSPregradoIngeniero Industria

Planning the delivery of home social services: a mathematical programming-based approach to support routing and scheduling assignments

The increased average lifespan, together with low birth rates, are transforming the European Union's age pyramid. Currently, we are experiencing a transition towards a much older population structure. Given that the institutions that provide care to these population groups are limited by budgetary constraints, it is imperative to optimize several processes, among which route planning and staff scheduling stand out. This dissertation aims to develop a mathematical programming model to support the planning of routes and human resources for providers of Home Social Services. Beyond general Vehicle Routing Problems assumptions, the proposed model also considers the following features: i) working time regulations, ii) mandatory breaks, iii) users' autonomy, and iii) meals' distribution. The present model, implemented using GAMS software, focuses simultaneously on two objective functions: minimization of operating costs, and maximization of equity through the minimization of differences in teams' working times. Chebyshev's method was chosen to solve the developed multiobjective model. The model was built based on a Portuguese Private Institution of Social Solidarity. Through the application of the model, significant improvements are obtained when compared to the current planning of the partner institution, such as it is the case of an improved workload distribution between caregivers and routes that will result in lower costs for the institution. This model is fully enforceable to other institutions that provide services similar or equal to the institution used as a reference.O aumento da esperança média de vida, juntamente com baixas taxas de natalidade, estão a transformar a pirâmide etária da União Europeia. Atualmente, estamos a vivenciar uma transição direcionada para uma estrutura populacional muito mais envelhecida. Dado que as instituições que prestam cuidados a esta fração se encontram limitadas por restrições orçamentais, torna-se imperativo otimizar vários processos, dos quais se destacam planeamento de rotas e escalonamento de funcionárias. Esta dissertação visa introduzir um modelo de programação matemática com a finalidade de apoiar o planeamento de rotas e recursos humanos para prestadores de Serviços de Apoio Domiciliário. O modelo assenta, além dos pressupostos de um "Vehicle Routing Problem", nos seguintes: i) regulações de tempo de trabalho, ii) pausas obrigatórias, iii) autonomia dos utentes, e iv) distribuição de refeições. O modelo, desenvolvido através de software GAMS, foca-se em duas funções objetivo, simultaneamente: minimização dos custos operacionais, e maximização da equidade, através da minimização das diferenças nos tempos de trabalho das equipas. O método de Chebyshev foi o escolhido para desenvolver o modelo multiobjetivo. O modelo foi construído tendo por base uma Instituição Particular de Solidariedade Social em Portugal. Através da aplicação do modelo, obtêm-se melhorias significativas, quando comparado com o atual planeamento da instituição parceira, como é o caso de uma melhor distribuição da carga de trabalho entre as funcionárias e das rotas que resultam da redução dos custos operacionais da instituição. Este modelo é totalmente extensível a outras instituições que prestem serviços semelhantes ou iguais à instituição utilizada como referência