14,176 research outputs found
Quality Based Software Project Staffing and Scheduling with Budget and Deadline
Abstract-Software project planning is becoming more complicated and important as the size of software project grows. Many approaches have been proposed to help project managers by providing optimal staffing and scheduling in terms of minimizing the salary cost or duration. Unfortunately, the software quality, another critical factor in software project planning, is largely overlooked in previous work. In this paper, we propose the quality based software project staffing and scheduling approach. We provide better software project plans considering quality with either cost bound (Budget) or duration bound (Deadline) for software project managers
Welcome to OR&S! Where students, academics and professionals come together
In this manuscript, an overview is given of the activities done at the Operations Research and Scheduling (OR&S) research group of the faculty of Economics and Business Administration of Ghent University. Unlike the book published by [1] that gives a summary of all academic and professional activities done in the field of Project Management in collaboration with the OR&S group, the focus of the current manuscript lies on academic publications and the integration of these published results in teaching activities. An overview is given of the publications from the very beginning till today, and some of the topics that have led to publications are discussed in somewhat more detail. Moreover, it is shown how the research results have been used in the classroom to actively involve students in our research activities
A heuristic procedure to solve the project staffing problem with discrete time/resource trade-offs and personnel scheduling constraints
Highlights • Project staffing with discrete time/resource trade-offs and calendar constraints. • An iterated local search procedure is proposed. • Different problem decomposition techniques are applied. Abstract When scheduling projects under resource constraints, assumptions are typically made with respect to the resource availability and activities are planned each with its own duration and resource requirements. In resource scheduling, important assumptions are made with respect to the staffing requirements. Both problems are typically solved in a sequential manner leading to a suboptimal outcome. We integrate these two interrelated scheduling problems to determine the optimal personnel budget that minimises the overall cost. Integrating these problems increases the scheduling flexibility, which improves the overall performance. In addition, we consider some resource demand flexibility in this research as an activity can be performed in multiple modes. In this paper, we present an iterated local search procedure for the integrated multi-mode project scheduling and personnel staffing problem. Detailed computational experiments are presented to evaluate different decomposition heuristics and comparison is made with alternative optimisation techniques
Search based software engineering: Trends, techniques and applications
© ACM, 2012. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version is available from the link below.In the past five years there has been a dramatic increase in work on Search-Based Software Engineering (SBSE), an approach to Software Engineering (SE) in which Search-Based Optimization (SBO) algorithms are used to address problems in SE. SBSE has been applied to problems throughout the SE lifecycle, from requirements and project planning to maintenance and reengineering. The approach is attractive because it offers a suite of adaptive automated and semiautomated solutions in situations typified by large complex problem spaces with multiple competing and conflicting objectives.
This article provides a review and classification of literature on SBSE. The work identifies research trends and relationships between the techniques applied and the applications to which they have been applied and highlights gaps in the literature and avenues for further research.EPSRC and E
An approach to software cost estimation
A general procedure for software cost estimation in any environment is outlined. The basic concepts of work and effort estimation are explained, some popular resource estimation models are reviewed, and the accuracy of source estimates is discussed. A software cost prediction procedure based on the experiences of the Software Engineering Laboratory in the flight dynamics area and incorporating management expertise, cost models, and historical data is described. The sources of information and relevant parameters available during each phase of the software life cycle are identified. The methodology suggested incorporates these elements into a customized management tool for software cost prediction. Detailed guidelines for estimation in the flight dynamics environment developed using this methodology are presented
Development and implementation of a computer-aided method for planning resident shifts in a hospital
Ce mémoire propose une formulation pour le problème de confection d'horaire pour résidents, un problème peu étudiée dans la litérature. Les services hospitaliers mentionnés dans ce mémoire sont le service de pédiatrie du CHUL (Centre Hospitalier de l'Université Laval) et le service des urgences de l'Hôpital Enfant-Jésus à Québec. La contribution principale de ce mémoîre est la proposition d'un cadre d'analyse pour l’analyse de techniques manuelles utilisées dans des problèmes de confection d'horaires, souvent décrits comme des problèmes d'optimisation très complexes. Nous montrons qu'il est possible d'utiliser des techniques manuelles pour établir un ensemble réduit de contraintes sur lequel la recherche d’optimisation va se focaliser. Les techniques utilisées peuvent varier d’un horaire à l’autre et vont déterminer la qualité finale de l’horaire. La qualité d’un horaire est influencée par les choix qu’un planificateur fait dans l’utilisation de techniques spécifiques; cette technique reflète alors la perception du planificateur de la notion qualité de l’horaire. Le cadre d’analyse montre qu'un planificateur est capable de sélectionner un ensemble réduit de contraintes, lui permettant d’obtenir des horaires de très bonne qualité. Le fait que l'approche du planificateur est efficace devient clair lorsque ses horaires sont comparés aux solutions heuristiques. Pour ce faire, nous avons transposées les techniques manuelles en un algorithme afin de comparer les résultats avec les solutions manuelles. Mots clés: Confection d’horaires, Confection d’horaires pour résidents, Creation manuelle d’horaires, Heuristiques de confection d’horaires, Méthodes de recherche localeThis thesis provides a problem formulation for the resident scheduling problem, a problem on which very little research has been done. The hospital departments mentioned in this thesis are the paediatrics department of the CHUL (Centre Hospitalier de l’Université Laval) and the emergency department of the Hôpital Enfant-Jésus in Québec City. The main contribution of this thesis is the proposal of a framework for the analysis of manual techniques used in scheduling problems, often described as highly constrained optimisation problems. We show that it is possible to use manual scheduling techniques to establish a reduced set of constraints to focus the search on. The techniques used can differ from one schedule type to another and will determine the quality of the final solution. Since a scheduler manually makes the schedule, the techniques used reflect the scheduler’s notion of schedule quality. The framework shows that a scheduler is capable of selecting a reduced set of constraints, producing manual schedules that often are of very high quality. The fact that a scheduler’s approach is efficient becomes clear when his schedules are compared to heuristics solutions. We therefore translated the manual techniques into an algorithm so that the scheduler’s notion of schedule quality was used for the local search and show the results that were obtained. Key words: Timetable scheduling, Resident scheduling, Manual scheduling, Heuristic schedule generation, Local search method
An exact optimization approach for personnel scheduling problems in the call center industry
Dissertação de mestrado em Engenharia de SistemasNowadays, the importance of the call center industry is increasing because they are a major mean of
communication between organizations and their costumers. So, ensuring good and optimized personnel
schedules in call centers is crucial and has several advantages: reduction of total labor costs, reducing
overstaffing, employees’ satisfaction, meeting their preferences, and costumers’ satisfaction, presenting
acceptable waiting times.
The considered problem concerns personnel scheduling in a 24/7 call center where the scheduling
process is done manually. So, the main goal is to explore exact solution approaches in order to obtain
solutions whose quality is preferable to the manually achieved ones and to reduce the processing time.
The proposed optimization model is an Integer Programming model. The purpose of this model is to
assign shifts to workers, while minimizing the total penalization that are associated to employees’ time
preferences. The model is implemented on ILOG CPLEX Optimization Studio 12.7.0.0, using OPL, and
tested with various instances, including randomly generated and real-world data instances. In order to
analyze the quality of the model, a computational study of its linear relaxation was carried out, concluding
that the model presents null integrality gaps in all the tested instances. So, the proposed model has a strong
formulation, that is, a good quality model. Additionally, to evaluate the performance of the model when
running large instances, several randomly generated instances were tested using ILOG CPLEX Optimization
Studio 12.10.0.0, achieving good computational results.Hoje em dia, a importância da indústria dos call centers tem vindo a aumentar, uma vez que estes são
um grande meio de comunicação entre as empresas e os respetivos clientes. Nesse sentido, garantir um
bom e otimizado escalonamento de pessoal é crucial e traz consigo bastantes vantagens: redução dos
custos totais de trabalho, reduzindo excesso de trabalhadores, aumento da satisfação dos empregados,
atendendo às suas preferências, e ainda aumento da satisfação dos clientes, apresentando tempos de
espera aceitáveis.
O problema considerado envolve escalonamento de pessoal num call center que opera 24 horas por dia,
7 dias por semana. Atualmente, o processo de escalonamento é feito manualmente. Assim, o principal
objetivo é explorar abordagens de resolução exata para obter soluções que apresentam qualidade preferível
às das soluções obtidas até ao momento e para reduzir o tempo gasto em todo o processo.
O modelo de otimização proposto é um modelo de Programação Inteira, cujo objectivo é associar turnos
de trabalho aos trabalhadores, minimizando o total das penalizações associadas às preferências horárias
dos mesmos. O modelo é implementado no ILOG CPLEX Optimization Studio 12.7.0.0, utilizando linguagem
OPL, e testado com várias instâncias, incluindo instâncias geradas aleatoriamente e instâncias
com dados reais. A análise da qualidade do modelo passou pelo estudo computacional da sua relaxação
linear, podendo concluir-se que o modelo apresenta um intervalo de integralidade nulo em todas as instâncias
testadas. Assim, o modelo proposto é um modelo forte, isto é, um modelo de boa qualidade. De
forma a avaliar o desempenho do modelo a resolver instâncias grandes, várias instâncias geradas aletoriamente
são testadas utilizando o software ILOG CPLEX Optimization Studio 12.10.0.0., apresentando bons
resultados computacionais
Overcoming Hurdles Implementing Multi-skilling Policies
Ogden ALC at Hill AFB has been authorized to promote wage grade employees if they are multi-skilled, but that authorization will expire at the end of Fiscal Year 2018. Simulation research by Capt Wesley Sheppard demonstrated significant cost savings/cost avoidance if multi-skilling is pursued, but there are significant challenges to implementation. This research examined two challenges in implementation. First, how many employees can be multi-skilled and still maintain proficiency in both skills? Second, once multi-skilled, is there a technique that can be applied to easily and effectively schedule the new multi-skilled workforce. Using linear programming, staffing numbers were calculated based on current manning and a minimum time policy to ensure the multi-skilled workforce has the opportunity to perform both skills. These calculations were based on a variety of inputs, such as output per man day (OPMD), different minimum time policies, an estimated lower bound, average, and upper bound for the annual workload, etc. Scheduling theory was applied to give schedulers and front line supervisors an easy to use heuristic that can make a significant difference in the amount of time it takes to complete a set of tasks. Various scheduling heuristics were applied to give supervisors an effective way to schedule the workforce
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