Planifier les affectations spatio-temporelles d’autrui : l’articulation d’enjeux économiques et sociaux par des ordonnanceurs

La construction des plannings de travail, aussi appelée ordonnancement du personnel, soulève de multiples enjeux, tant économiques que commerciaux ou encore sociaux. Elle représente notamment un levier pour construire des conditions de travail satisfaisantes. Au lieu de s’intéresser aux impacts de l’absentéisme sur l’activité des agents présents au travail, comme fréquemment discuté dans la littérature ergonomique, le but de cet article est de présenter l’activité de conception de ces plannings de travail, c’est-à-dire celle d’ordonnanceurs d’une grande entreprise ferroviaire dans un contexte de flexibilité et de compétitivité accrues.À partir de l’analyse de leur activité, nous montrons comment les ordonnanceurs développent un travail d’articulation à la fois entre les différents acteurs concernés par les plannings, mais également entre les différentes dimensions de la production (économique, commerciale, sociale…) afin de construire des plannings acceptables et acceptés. Ce travail d’articulation constitue alors un levier pour la gestion de l’absentéisme et la prévention des troubles de santé chez ces opérateurs.Conjointement ces régulations sont mises au regard avec l’indicateur de pilotage utilisé par l’organisation pour rendre compte de cette activité d’ordonnancement. Le contraste des analyses d’activité avec celles issues des indicateurs de suivi mis en place au sein de l’unité montre que ces articulations sont souvent masquées, et peuvent se montrer en contradiction avec les décisions de la direction.The construction of work schedules, also known as personnel scheduling, raises several economic, commercial and social issues. In particular, it represents a lever for building satisfactory working conditions. Instead of focusing on the impacts of absenteeism on the activity of agents present at work, as frequently discussed in the ergonomic literature, the purpose of this article is to present the activity of designing these work schedules, i.e. that of schedulers in a large railway company in a context of increased flexibility and competitiveness.Based on the analysis of their activity, we show how schedulers develop a work of articulation both between the different actors concerned by the schedules, and between the different dimensions of production (economic, commercial, social, etc.) in order to build acceptable and accepted schedules. This articulation work thus constitutes a lever for managing absenteeism and for preventing health problems among the operators in question. At the same time, these regulations are compared with the management indicator used by the organization to report on this scheduling activity. The contrast between the activity analyses and those resulting from the monitoring indicators set up within the unit shows that these links are often hidden and can be inconsistent with management decisions

Iterative restart technique for solving timetabling problems

Abstract Restart techniques for randomizing complete search algorithms were proposed recently by Selman and Gomes, for solving hard combinatorial problems. A new iterative algorithm that uses restart techniques is proposed, and its behavior analyzed on random timetabling problems. Employee timetabling problems (ETPs) can naturally represented by constraints networks for real world instances which are large and difficult. Complete search algorithms, even with good heuristics are unable to solve large enough instances of ETPs. In fact, several local search techniques have been proposed in the past decade for solving timetabling problems. In particular, it has been shown that local search can efficiently solve large ETPs. Random instances of ETPs that was generated based on real world ETPs are used to test the proposed iterative restart algorithm- GIRA. The two main parameters of GIRA are pointed out and investigated: the initial cutoff value for restart and the number of idle iterations. For random sets of a large range of hardness of ETPs, the successful values of these two parameters tend to be surprisingly low. We conclude by recommending an optimal range of values for the initial cutoff and demonstrate experimentally that the number of idle iterations is of little consequence