Decision-based genetic algorithms for solving multi-period project scheduling with dynamically experienced workforce

The importance of the flexibility of resources increased rapidly with the turbulent changes in the industrial context, to meet the customers’ requirements. Among all resources, the most important and considered as the hardest to manage are human resources, in reasons of availability and/or conventions. In this article, we present an approach to solve project scheduling with multi-period human resources allocation taking into account two flexibility levers. The first is the annual hours and working time regulation, and the second is the actors’ multi-skills. The productivity of each operator was considered as dynamic, developing or degrading depending on the prior allocation decisions. The solving approach mainly uses decision-based genetic algorithms, in which, chromosomes don’t represent directly the problem solution; they simply present three decisions: tasks’ priorities for execution, actors’ priorities for carrying out these tasks, and finally the priority of working time strategy that can be considered during the specified working period. Also the principle of critical skill was taken into account. Based on these decisions and during a serial scheduling generating scheme, one can in a sequential manner introduce the project scheduling and the corresponding workforce allocations

A greedy heuristic approach for the project scheduling with labour allocation problem

Responding to the growing need of generating a robust project scheduling, in this article we present a greedy algorithm to generate the project baseline schedule. The robustness achieved by integrating two dimensions of the human resources flexibilities. The first is the operators’ polyvalence, i.e. each operator has one or more secondary skill(s) beside his principal one, his mastering level being characterized by a factor we call “efficiency”. The second refers to the working time modulation, i.e. the workers have a flexible time-table that may vary on a daily or weekly basis respecting annualized working strategy. Moreover, the activity processing time is a non-increasing function of the number of workforce allocated to create it, also of their heterogynous working efficiencies. This modelling approach has led to a nonlinear optimization model with mixed variables. We present: the problem under study, the greedy algorithm used to solve it, and then results in comparison with those of the genetic algorithms

Project scheduling with multi skilled resources: a conceptual framework

Projects’ success depends, mostly, on people’s motivation and competences. A good plan is essential, but it is insufficient if the project manager is incapable to dynamically reassign people to project’s tasks, so as to create multi-skilled teams and to avoid multi-tasking and over-allocation. In this regard, several models dealing with the “Multi Skilled Work Force Scheduling Problem” have been proposed, but unfortunately, most of the works produced so far has not yet found its way into practice. This is mainly because project scheduling and resources allocation are jointly considered, a fact that leads to complex and rigid mathematical formulations and that poses serious constraints on the precision of the input data. Since projects are, by their very nature, uncertain entities, we believe that it is preferable to abandon the over optimistic idea of a global optimum, in favour of a suboptimal but stable and feasible solution. To this aim the paper proposes a heuristic framework that extends the well-known “Dynamic Scheduling” approach. Specifically, the problem is tackled in a hierarchical way: project scheduling is solved first and resource allocation is solved next, considering tasks durations as fixed constraints. In doing so, our focus is on the resources allocation phase, and the objective is to assure an almost perfect matching between resources’ skills and tasks requirements, so as to assure project quality and, also, a harmonious development of the workforce. Possible approaches, based on mathematical programming, which could be easily implemented in project management software, are presented and discussed

Flexible resources allocation techniques: characteristics and modelling

At the interface between engineering, economics, social sciences and humanities, industrial engineering aims to provide answers to various sectors of business problems. One of these problems is the adjustment between the workload needed by the work to be realised and the availability of the company resources. The objective of this work is to help to find a methodology for the allocation of flexible human resources in industrial activities planning and scheduling. This model takes into account two levers of flexibility, one related to the working time modulation, and the other to the varieties of tasks that can be performed by a given resource (multi–skilled actor). On the one hand, multi–skilled actors will help to guide the various choices of the allocation to appreciate the impact of these choices on the tasks durations. On the other hand, the working time modulation that allows actors to have a work planning varying according to the workload which the company has to face

Prise en compte des évolutions de compétences pour les ressources humaines

Les impératifs croissants de réactivité des entreprises manufacturières face à l’instabilité des marchés suscite un fort besoin de flexibilité dans leur organisation. Le personnel de l’entreprise étant de plus en plus considéré comme le noyau de la structure organisationnelle, une bonne gestion prévisionnelle des ressources humaines et de leurs compétences s’avère capitale pour les performances dans de nombreux secteurs industriels. Ces organisations se doivent d’élaborer des stratégies à court, moyen et long termes concernant la préservation et le développement des compétences. Dans cet article, nous nous penchons sur la programmation de projet multi-périodes, en considérant le problème de l’affectation des effectifs avec deux degrés de flexibilité. Le premier résulte de l’annualisation du temps de travail, et concerne les politiques de modulation d’horaires, individuels ou collectifs. Le deuxième degré de souplesse est la polyvalence des opérateurs, qui induit une vision dynamique de leurs compétences et la nécessité de prévoir les évolutions des performances individuelles en fonction des affectations successives. Nous sommes résolument dans un contexte où la durée prévue des activités n’est plus déterministe, mais résulte des performances des acteurs choisis pour les exécuter. Nous présentons ici une modélisation mathématique de ces compétences, et la résolution d’un exemple de planification basée sur les algorithmes génétiques

Propuesta de mejora a los altos tiempos de espera en puntos de atención al usuario en una entidad promotora de salud empleando simulación discreta

Health services anywhere in the world must ensure a timely, safe and high quality of care. Therefore, health promotion entities in Colombia (EPS) must ensure easy and streamlined processes in the services offered, avoiding risks that can affect the lives of patients. Along with the above, in Colombia law anti-procedures is defined, with the implementation of this law is created an issue for the EPS because they are serving more than 250,000 users in cities like Medellin (Colombia). This causes agglomeration of patients, complaints and objections from members by the long lines and delays in the procedures that are presented at the point of customer service. To this end, the entity wishes to reduce service times to avoid a penalty by the superintendent of Colombian health using simulation as a tool and perform an efficient proposal to decrease the costs and possible penalties.Los servicios de salud en cualquier parte del mundo deben asegurar una atención oportuna, segura y de alta calidad (Quality of Care). Por lo tanto, las entidades promotoras de salud en Colombia (EPS) deben garantizar procesos fáciles y ágiles en los servicios ofrecidos, evitando riesgos que pueden afectar la vida de los pacientes. Junto con lo anterior, en Colombia se definió la ley anti-tramites, siendo el cumplimiento de esta ley una problemática para las EPS ya que prestan servicios a más de 250.000 usuarios en ciudades como Medellín (Colombia). Esta aglomeración de pacientes ocasiona quejas e inconformidades de parte de los afiliados por las largas filas y demoras en los trámites que se presentan en el punto de atención al usuario. Para tal fin, la entidad desea disminuir los tiempos de atención, para evitar una sanción por parte de la superintendencia de salud colombiana, empleando como herramienta la simulación y realizar una propuesta eficiente que disminuya los costos y posibilidades de sanción

Considering skills evolutions in multi-skilled workforce allocation with flexible working hours

The growing need of responsiveness for manufacturing companies facing market volatility raises a strong demand for flexibility in their organisation. Since the company personnel are increasingly considered as the core of the organisational structures, a strong and forward-looking management of human resources and skills is crucial to performance in many industries. These organisations must develop strategies for the short, medium and long terms, in order to preserve and develop skills. Responding to this importance, this work presents an original model, looking at the line-up of multi-period project, considering the problem of staff allocation with two degrees of flexibility. The first results from the annualising of working time, and relies on policies of changing schedules, individually as well as collectively. The second degree of flexibility is the versatility of the operators, which induces a dynamic view of their skills and the need to predict changes in individual performance as a result of successive assignments. We are firmly in a context where the expected durations of activities are no longer predefined, but result from the performance of the operators selected for their execution. We present a mathematical model of this problem, which is solved by a genetic algorithm. An illustrative example is presented and analysed, and, the robustness of the solving approach is investigated using a sample of 400 projects with different characteristics