*2.2. Planning Methods for Construction Projects*

#### 2.2.1. Traditional French Job Titles and Planning Process

Planning a construction project involves identifying, for each stage of the project, the activities to be carried out in order to achieve the desired objectives. The activities must then be broken down into elementary tasks so as to be scheduled with respect to the technical, economic, and specific constraints of the project. By doing so, the resulting deliverable makes it possible to clearly explain the detailed progress of the project, while validation milestones ensure the measuring of progress and the quality of the services to be performed.

In a construction project, a schedule is developed by the client, noting the project's feasibility. This preliminary schedule rarely details each of the project tasks because many of them are still unknown or might be deleted and/or modified. However, it enables a quick assessment of the project duration in its early stages, despite a significant degree of uncertainty. To respond to project tenders, bids are expressed using the envelope planning of the project owner (in French the maître d'ouvrage, or MOA) as input. The granularity of tasks is reduced to make improvements and confirm or reject the initial duration expectations. Finally, before the construction phase, companies must also create execution schedules based on the general planning of the project entity in charge of the implementation of the project (the company, firm, department, or person called in French the maître d'oeuvre, or MOE). These schedules take into account their ability to mobilize

the necessary resources, delivery times for supplies, and scheduling constraints that link them to other onsite activities [50].

As the activities of all project participants are strongly interconnected in time and space, it is fundamental to collaborate throughout the whole project in order to reduce the impacts of potential causes of delay. This is precisely the role of the scheduling, management, and coordination team (in French the Ordonnancement, Pilotage, Coordination or OPC); to bring together and synchronise all the schedules as well as to be the unique contact for project participants to coordinate activities in case of any conflicts or problems. Depending on the nature and context of the project, the OPC may implement and use different planning methods. It should be noted that, in this paper, although generic role descriptors have been used where possible, occasionally it has been necessary to use French job titles. These, and their English equivalents, are provided in Appendix A, Table A1.

#### 2.2.2. Planning Methods

Several classes of scheduling methods have been identified through the review and analysis of various literature concerning construction planning [51]. The most known and used are (a) the Critical Path method, (b) the Line-of-Balance method, (c) the Program Evaluation and Review Technique (PERT), (d) simulation methods, (e) AI-based methods, (f) visualisation methods, (g) Critical Chain scheduling, (h) location-based scheduling, and (i) Lean methods. These are detailed in the following paragraphs.

