IsoBIM 2-year postdoctoral researcher: 09/01/2021– 08/30/2023
Last Planner System process implementation: state of the art and development of
interactive scheduling models under constraints associated with 4D simulation.
The ISoBIM ANR project (Proposal for a collaborative process for retrofitting by external Insulation based on Lean and BIM paradigms) aims to provide an original response to the development of energy renovation activities. At the same time, it seeks to help SMEs in the wood construction trade to achieve digital transition and to improve their productivity. The ISOBIM proposal is innovative. On the one hand, because it seeks to cover the entire renovation process from the identification of the constructive solution, through the elaboration of configuration and layout models, to the elaboration of planning models and monitoring of construction projects. And, on the other hand, because of its holistic and anthropocentric approach, which is part of a break with scientific research in the field of control and management of industrial/building systems. This study will focus on the sub-process of planning and scheduling of construction site activities.
The large size of the panels (from a few m² to more than 30 m²) as well as their mass (from 50 kg to a few tons) lead to problems of planning and scheduling activities at finite capacity of critical resources such as cranes, storage areas or means of transport for the lifting of these panels. Thus, the problem of planning and scheduling renovation activities on a building site can be seen as a classic Resource Constrained Project Scheduling Problem (RCPSP) which consists in minimizing the duration of a project by satisfying constraints of precedence and availability of resources. However, in the context of renovation, activities are subject to multiple disruptions that can degrade project performance: poorly estimated task durations, unavailability of unplanned resources, weather conditions, etc. Two directions can be explored: a response to these uncertainties by (i) the establishment of a robust plan or by (ii) a dynamic resequencing based on the real constraints of the construction site. Considering the holistic and anthropocentric approach defended in this project, the path that we wish to explore is the use of the Last Planner System as a planning process based on the animation of four different schedules.
Objective and challenges: The implementation of an LPS therefore implies the design of a model in several plans, each plan being the place for a set of decisions of specific periodicities and horizons. This step is crucial because inadequate temporal horizon and frequency of rescheduling can lead to a desynchronization of the different schedules. In addition, the plans structuration, the constraints identification, and their modeling as well as the implementation of performance indicators for measuring the reliability of the schedules are not trivial. Moreover, they are often only based on business practices and planners’ know-how (which is one of the barriers to the adoption of LPS).
A first objective will be, based on a depth literature study, to propose a formalization of these good practices and a methodological guideline for the implementation of the LPS for ISOBIM’s target projects. Moreover, for several years, research on hierarchical planning structures has shown the importance of the principle of disaggregating decisions from one level to another. A poor coordination of planning objectives or the propagation of constraints between levels will also lead to a desynchronization of schedules and consequently a less efficient planning. The study of the literature on LPS shows that no explicit link between the lower levels of the plan and the higher level is formalized. To keep the principle of LPS autonomy while guiding the actors of the construction site in their decision making. A first track will be to develop interactive optimization models under constraints at each level and to couple them with BIM4D simulation tools to validate the decisions of the level in question and their impacts on the schedules of the higher levels. In this context, combining BIM and planning methods is an important challenge. The development of these optimization models and the definition and specification of the simulation models will be the second and main objective of this thesis.
Candidate profile :
- Doctorate (Phd) in civil engineering or industrial engineering with a significant experience on constructionmanagement.
- Competencies on digital & BIM environments for construction and on optimization planning methods.
- Knowledges on Lean practices would be a plus.
- Teamwork skills.
Salary: Depending on the candidate profile
Planned start-up: September 2021.
Contact: Prof. Hind BRIL EL HAOUZI hind.el-haouzi@univ-lorraine.fr