An application of demand profiling and optimisation of staffing levels within Leicestershire Police Force

In modern society there is a necessity for industries to maximise their productivity but also to minimise their outlay, be that in the form of equipment or personnel. Motivated by interest within UK policing towards professionalization of their service, the dual problem of modelling the demands upon front-line Police officers and the optimisation of available resources is investigated. Demand borne from calls to service from the general public is considered and a method whereby this may be realistically quantified in a predictive model is shown. An optimisation technique is described that minimises the number of staff required in order to meet expected demand using a user input series of shift definitions. A tool is created that contains both the demand profiling and optimisation functions described. The effectiveness of this tool is then shown by application to the shift allocation of Police personnel with results illustrating this provided

A time predefined variable depth search for nurse rostering

This paper presents a variable depth search for the nurse rostering problem. The algorithm works by chaining together single neighbourhood swaps into more effective compound moves. It achieves this by using heuristics to decide whether to continue extending a chain and which candidates to examine as the next potential link in the chain. Because end users vary in how long they are willing to wait for solutions, a particular goal of this research was to create an algorithm that accepts a user specified computational time limit and uses it effectively. When compared against previously published approaches the results show that the algorithm is very competitive

Fairness aspects in personnel scheduling

In industries like health care, public transport or call centers a shift-based system ensures permanent availability of employees for covering needed services. The resource allocation problem – assigning employees to shifts – is known as personnel scheduling in literature and often aims at minimizing staffing costs. Working in shifts, though, impacts employees’ private lives which adds to the problem of increasing staff shortage in recent years. Therefore, more and more effort is spent on incorporating fairness into scheduling approaches in order to increase employees’ satisfaction. This paper presents a literature review of approaches for personnel scheduling considering fairness aspects. Since fairness is not a quantitative objective, but can be evaluated from different point of views, a large number of fairness measurements exists in the literature. Furthermore, perspective (group vs individual fairness) or time horizon (short-term vs long-term fairness) are often considered very differently. To conclude, we show that a uniform definition and approach for considering fairness in personnel scheduling is challenging and point out gaps for future research

Satisfaction distribuée de contraintes et son application à la génération d’un emploi du temps d’employés

La génération d'emplois du temps d'employés (ETP pour Employee Timetabling Problem) est abordée dans cet article d'un point de vue multiagent afin de donner un cadre d'étude à la coordination distribuée soutenue par la communication. Nous nous sommes penchés plus particulièrement sur le cas des établissements scolaires en cherchant à affecter des professeurs et des salles à des cours en respectant des créneaux horaires. Ce problème d'ETP est formalisé sous la forme d'un problème de satisfaction de contraintes distribué (DCSP pour Distributed Constraints Satisfaction Problem). Un algorithme à retour arrière résolvant ce DCSP est alors proposé. Un tel algorithme génère à la fois l'emploi du temps recherché et la coordination des agents qui vont le suivre. Enfin, nous expliquons comment un tel algorithme a été implémenté et validé.5e Congrès international de génie industriel, Le génie industriel et les nouveaux défis mondiaux Université Laval, Sainte-Foy, Québec, Canada (26 au 29 octobre 2003

Graph coloring based heuristic for crew rostering

In the last years personnel cost became a huge factor in the financial management of many companies and institutions.The firms are obligated to employ their workers in accordance with the law prescribing labour rules. The companies can save costs with minimizing the differences between the real and the expected worktimes. Crew rostering is assigning the workers to the previously determined shifts, which has been widely studied in the literature. In this paper, a mathematical model of the problem is presented and a two-phase graph coloring method for the crew rostering problem is introduced. Our method has been tested on artificially generated and real life input data. The results of the new algorithm have been compared to the solutions of the integer programming model for moderate-sized problems instances

Dynamic allocation of operators in a hybrid human-machine 4.0 context

La transformation numérique et le mouvement « industrie 4.0 » reposent sur des concepts tels que l'intégration et l'interconnexion des systèmes utilisant des données en temps réel. Dans le secteur manufacturier, un nouveau paradigme d'allocation dynamique des ressources humaines devient alors possible. Plutôt qu'une allocation statique des opérateurs aux machines, nous proposons d'affecter directement les opérateurs aux différentes tâches qui nécessitent encore une intervention humaine dans une usine majoritairement automatisée. Nous montrons les avantages de ce nouveau paradigme avec des expériences réalisées à l'aide d'un modèle de simulation à événements discrets. Un modèle d'optimisation qui utilise des données industrielles en temps réel et produit une allocation optimale des tâches est également développé. Nous montrons que l'allocation dynamique des ressources humaines est plus performante qu'une allocation statique. L'allocation dynamique permet une augmentation de 30% de la quantité de pièces produites durant une semaine de production. De plus, le modèle d'optimisation utilisé dans le cadre de l'approche d'allocation dynamique mène à des plans de production horaire qui réduisent les retards de production causés par les opérateurs de 76 % par rapport à l'approche d'allocation statique. Le design d'un système pour l'implantation de ce projet de nature 4.0 utilisant des données en temps réel dans le secteur manufacturier est proposé.The Industry 4.0 movement is based on concepts such as the integration and interconnexion of systems using real-time data. In the manufacturing sector, a new dynamic allocation paradigm of human resources then becomes possible. Instead of a static allocation of operators to machines, we propose to allocate the operators directly to the different tasks that still require human intervention in a mostly automated factory. We show the benefits of this new paradigm with experiments performed on a discrete-event simulation model based on an industrial partner's system. An optimization model that uses real-time industrial data and produces an optimal task allocation plan that can be used in real time is also developed. We show that the dynamic allocation of human resources outperforms a static allocation, even with standard operator training levels. With discrete-event simulation, we show that dynamic allocation leads to a 30% increase in the quantity of parts produced. Additionally, the optimization model used under the dynamic allocation approach produces hourly production plans that decrease production delays caused by human operators by up to 76% compared to the static allocation approach. An implementation system for this 4.0 project using real-time data in the manufacturing sector is furthermore proposed

Problema de Afetação de Recursos com Diferentes Competências

O problema em estudo neste trabalho, designado por Problema de Afetação de Recursos com Diferentes Competências, surgiu no contexto de uma empresa de retalho na qual é necessário planear a distribuição de tarefas pelos funcionários ao longo de um horizonte de planeamento e de acordo com o que se conhece nunca foi abordado na literatura. Cada funcionário possui um conjunto de competências que poderá alargar através de formação on job, pois o desempenho de qualquer função apenas pode ocorrer se o funcionário possuir competência para tal. Caso a mão de obra existente não seja suficiente para satisfazer a procura, existe a possibilidade de recurso a outsourcing, para algumas funções. Todos os funcionários a exercerem funções auferem um salário correspondente à função exercida. O problema descrito foi formulado em Programação Linear Inteira considerando um modelo multi-periódico, pois a afetação será feita para cada período do horizonte de planeamento. O modelo desenvolvido tem como objetivo a minimização dos custos de afetação, tendo em conta a satisfação da procura de mão de obra ao longo do horizonte temporal, o conjunto de competências de cada funcionário e ainda o recurso a formação e/ou outsourcing. O modelo pode ser adaptado com novos conjuntos de restrições, tais como a inclusão de regras laborais ou a variação de custos. Foi realizada uma experiência computacional com dados gerados para o efeito, dada a impossibilidade de utilização de dados reais. Os resultados obtidos demonstram que a influência da formação no conjunto de competências dos funcionários e na afetação e que o recurso a outsourcing apenas se verifica quando é estritamente necessário para satisfazer a procura e não existem funcionários disponíveis para tal

Solving Challenging Real-World Scheduling Problems

This work contains a series of studies on the optimization of three real-world scheduling problems, school timetabling, sports scheduling and staff scheduling. These challenging problems are solved to customer satisfaction using the proposed PEAST algorithm. The customer satisfaction refers to the fact that implementations of the algorithm are in industry use. The PEAST algorithm is a product of long-term research and development. The first version of it was introduced in 1998. This thesis is a result of a five-year development of the algorithm. One of the most valuable characteristics of the algorithm has proven to be the ability to solve a wide range of scheduling problems. It is likely that it can be tuned to tackle also a range of other combinatorial problems. The algorithm uses features from numerous different metaheuristics which is the main reason for its success. In addition, the implementation of the algorithm is fast enough for real-world use.Siirretty Doriast

Integração e reformulação de modelos de escalonamento no serviço de centro de contactos

Tese de mestrado em Estatística e Investigação Operacional, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2014O estágio a que se refere este relatório foi efectuado no Departamento de Scheduling da empresa Teleperformance Portugal. Esta é uma empresa multinacional francesa fundada em 1978, que fornece serviços de apoio ao consumidor, suporte técnico, telemarketing e de centro de contactos (call center) a outras empresas. Representa empresas internacionais dos mais variados sectores em operações de atendimento ao cliente que abrangem mais de 66 idiomas diferentes. Como é uma empresa que funciona essencialmente com base em agentes telefónicos, com o crescimento da empresa surgiu a necessidade de criar uma forma de distribuir os funcionários pelos seus postos de trabalho de forma a melhorar o nível de serviço (aumentar o número de chamadas atendidas e de chamadas efectuadas com sucesso), aumentando os lucros e ao mesmo tempo reduzindo o número de recrutamentos desnecessários. Assim sendo, a empresa acabou por recorrer a métodos de investigação operacional que permitam optimizar a geração dos horários dos seus agentes. Sendo que aquando do início deste estágio a empresa já utilizava alguns modelos matemáticos, o intuito geral deste consistiu então na reformulação destes modelos já existentes e na construção de um único que permita abranger todas as situações a considerar na geração dos diferentes horários. Para além da apresentação dos modelos iniciais e do final, serão ainda apresentados e descritos neste relatório todos os desenvolvimentos que foram solicitados à equipa informática da empresa no âmbito da construção do novo modelo.This report is about an internship at the Planning Department of Teleperformance, a French Multinational Company which was founded in 1978. Teleperformance provides customer and technical support, telemarketing and call center services to others companies. It has been serving companies around the world, operating in various industries and conducting programs in more than 66 different languages. This company works basically with customer service representatives (CSR) and with its growing arose the need of developing a way to allocate employees to their workstations, increasing the number of incoming and outcoming calls and maximizing the profits, as well as, minimizing the number of unnecessary recruitments. To be able to do this, the company decided to use operational researching methods which would optimize the schedules generation. At the beginning of this internship the company was already using some mathematical models, so the main goal was to reformulate the existing models and create a new one that would embrace all the possible situations for the different schedules. Finally in this report, as well as the presentation of the existing models and the final model, it will still be present and described all developments required in the internship that have been requested to the IT Department

Network based data oriented methods for application driven problems

Networks are amazing. If you think about it, some of them can be found in almost every single aspect of our life from sociological, financial and biological processes to the human body. Even considering entities that are not necessarily connected to each other in a natural sense, can be connected based on real life properties, creating a whole new aspect to express knowledge. A network as a structure implies not only interesting and complex mathematical questions, but the possibility to extract hidden and additional information from real life data. The data that is one of the most valuable resources of this century. The different activities of the society and the underlying processes produces a huge amount of data, which can be available for us due to the technological knowledge and tools we have nowadays. Nevertheless, the data without the contained knowledge does not represent value, thus the main focus in the last decade is to generate or extract information and knowledge from the data. Consequently, data analytics and science, as well as data-driven methodologies have become leading research fields both in scientific and industrial areas. In this dissertation, the author introduces efficient algorithms to solve application oriented optimization and data analysis tasks built on network science based models. The main idea is to connect these problems along graph based approaches, from virus modelling on an existing system through understanding the spreading mechanism of an infection/influence and maximize or minimize the effect, to financial applications, such as fraud detection or cost optimization in a case of employee rostering