Planning is actually articulating these different levels or thematics, these levels of comprehension. In the end, their articulation makes the planning effective or efficient, and little by little, we will be able to make it sustainable. There are different kinds of planning tools. We use the most common ones. First, the orientation requirements. This is what we call "SDAU, PUR, SDU and PSU". They are city planning and urbanism guidelines, urban reference plans, master plans, and urban development patterns. So, all the denominations are possible, but to sum up, we have two main types. The orientation requirements, and requirements for land use, which are applicable to third parties. So, everything about orientation is for the public institutions, but it's not legally enforceable for the private sector. We do hope these orientations are easy to understand. And everything about land use requirements is applicable to third parties, so it is valid for both public and private sectors. These are the housing scheme plans, the area plans, and the land use plans in general. I mentioned the land use plans earlier or simple housing development plans. And between the two, we have a tool, often ill-defined, which could be the urban master plans, or localized master plans. They only exist in a few countries, but we have, here, between them, between the orientation, and the land use requirements, some tools. We tend to develop these tools, as we see the limitations of the master plans and of the land use plans. So, we try to have between the two, some documents that would be prescriptive, and would give great orientations. Tools for planning, such as an SDAU or PUR, what are their features ? The first one should be flexibility. So, the tool must be able to evolve quickly. But it is also a coordination tool. It is a short-duration tool, despite the long history of cities. It should express a common vision, and show as a priority objectives with strong potential. The main objectives, and the secondary ones-- we agree that the tool should in priority be based on the objectives with strong potential. We can imagine that the tool is created in a very short analysing phase. If the tool is made to last ten years, and you take five or six years to set it up, the data that you will have at that time will not be valid anymore. And before being able to set it up, you will have to update it again. So, it is endless, which means that it is more interesting for us to make short-duration tools, which last ten years, like I said, but that can be made in six months, in a year or two. If it is takes longer, the data are not valid and it already needs updating. The most important feature that we often forget, is that the tool has to add up to what already exists. So as planners, there are things that are bothering us, things that we would like to see elsewhere. But we can't move them. Some projects have already started and we can't just erase them like they don't exist. So, we take them into account, and we add our planning to what already exists. So, the objective of the tool is to plan the key elements, to give a reference to the urban development to limit the urban perimeter. So, it is actually a choice of perimeter, which might be secondary, but that allows us to delimit the administrative territory of the city. It usually tries to anticipate the land reserves. So we can underline the land question as it is essential when planning to offer a certain number of areas. For example, if a chain of hotels decides to build a hotel in an African city, can I offer several possibilities of land when I look into my plans? The building of a new ministry is decided. Is this building in my plans? This is very basic and pragmatic. But if we start analysing the existing plans, we will see that this part is rare. As I said earlier, the main objective is to articulate the different thematics. It is useless to make a list of things, they have to be in harmony. And what is more and more important is to share a vision. It is useless to plan, if it is not shared between all actors. There are many actors as we saw in the video about the African city. We know the actors are both institutional and private, formal and informal, and all of these people must share the vision. Very simple methodology, very common. We will qualify that afterwards. We first have a diagnostic. This diagnostic allows us to define orientations. So, we have to focus on that. It is a chain. If there is no diagnostic, then, we politically define other orientations. No. It is based on the diagnostic that we will define orientations for tomorrow's city. Those orientations are political. And, we will translate these orientations, elaborate them with a plan. Translating them in a project has an impact on the plan. This will make us go from diagnostic to some orientations, then to the elaboration of a plan, and a program of priority investment. It is not elementary data, but today, it is the basic pattern to set up a master plan. Then, there will be the implementation and what we forget at the end, but is also essential, is the communication. You have to be able to sell the plan you set up to make it useful. The diagnostic, is in fact, an initial evaluation. We will have a look at what we learned about the city. We will make a table of these findings which gives us the opportunities, the strengths, the weaknesses and threats of the internal and external issues of the city. Let's look at the example of N'Djamena, Chad. This diagnostic was made quickly, but allows us to see the main elements, therefore, the main issues of the city. Following the diagnostic, we will elaborate some orientations. What are the big objectives for my city? After defining the orientations, we make a plan. So along the plan, we will spatialise the orientations. Once it is done, the result is the urban plan, a framework document. It does not have the same status as an SDAU or master plan, but some orientations have been spatialised, and the result is the urban plan. After the "PIP", Program of Priority Investment, the cities can usually submit some projects to a sponsor who will finance them. This is the reason for the Program of Priority Investment. What are the priority investments to implement in my city, to start orienting and meeting the objectives I have set? Then, the implementation. Having a good plan is not enough, it has to be implemented. And for that, we need to have an action plan, to formalise the actions, to identify the different responsibilities, the funding sources, the schedules and set up a monitoring system to have indicators. That is also often forgotten at the end of the planning. Your planning is useless without a monitoring system or an indicator system which informs you if you are realising what you have planned, or if you have negative effects which cause the planning to go the opposite way you planned. Finally, communication. Every resident must know the orientations and the vision of their city. It is another strong wish, but it is very difficult to go to all neighbourhoods to discuss it. But the more you communicate, the bigger the consensus on the project. To do so, you will need the media, a clear message, easy to understand and the use of what already worked as a learning lesson. The last two elements are very important, as it is basic communication. But the message has to be clear and easy, so everyone can understand what is it about. Now, as we have some indicators, we have to evaluate what we did. We can do so in time or as we plan but no matter how many years it takes, the idea is to have a return on the planning. We will come back to these elements, but quickly, the idea is to have an overview on planning by giving a definition, some thematics, and show that we can't work separately, with separate thematics, but that it needs to be articulated. Finally, planning is articulating this urban complexity. We thought for a long time that the more we simplify the planning the more efficient it would be. We witness the exact opposite. In the planning today, we must take into account the complexity of the societies and of the urban operating to have a lever for action for tomorrow's city, and set up a sustainable city.