Calculation of the construction sites' occupancy rate using chonographic modeling

Trying to prevent stagnation and regressing productivity in the construction industry is as complex as trying to measure and identify the factors that influence it. The introduction of Building Information Modeling (BIM) has impacted the visualization and flow of information, and forced the industry to review its management practices, methods and techniques. BIM was originally intended for the design prospect. When applied to construction and operation phases, producing 4D simulations requires significant revisions to the model and project schedules, particularly to characterize the spatial nature of projects. This is due to several factors, including the limitations of scheduling techniques. These techniques model either a bar chart diagram that hardly represents time-space constraints, or a linear diagram scheduling method that is not suitable for model building projects. It is hard to show the work sequence, circulation and supply flow between different sites on a construction project. The efficiency of Lean Manufacturing has attracted the construction industry's attention, mainly to stabilize workflow with TAKT-Time planning. The Last Planner system has been developed to create more realistic schedules. Based on Lean Construction, the Last Planner involves those in charge of carrying out the work. In order to develop better-adapted and more flexible models, Chronographic Modeling, based on spatial modeling concepts, aims to represent construction site flow and operations properly. Based on this model, the current paper proposes a new operation process to facilitate 4D simulation. This process classifies and characterizes the types of project stages, operations, flow, and spaces. Construction stages are divided according to the construction phases, namely: I) Space creation, ii) Systems, iii) Space division, iv) Finishing work, and v) Closing of space. The operation process and flow includes repetitive, unique, and spontaneous tasks, which are classified as either exclusive or inclusive. Space occupations are specified as spatial, linear or isolated, and zones are divided into floors, sectors and exteriors. The model also considers the size and continuity of the teams as well as the occupancy rate of the site. Application of the model on a case study demonstrates its adaptability to 4D simulations.