 Project management techniques, they are two popular techniques which are used in project management. These are one is critical path method. And the other one is a program evaluation and review technique. It is program evaluation and review technique and CPM critical path method. Both of these techniques were developed in 1950s. We will go ahead with its details. The framework of both these techniques, basically it is that first we have to define the project. Its work breakdown structure, which is called WBSP, we have to develop that. After that we have to see which activities, with which activities it is related. Precedence precedes that it is following the activity. There are some activities which do not have a link, so they can be performed simultaneously or in any sequence. Because they do not have a link. If there is a link, then we will have to meet the precedence requirement. So which activities will precede, which activities will follow. And then on the basis of that we have to draw the network, which we call precedence network and precedence diagram of all these activities. Because precedence diagram clearly shows us that although we can write, but we do not have a clear picture in it. It can also be a table, which activities are there, which will be performed first, then it will start. It can also be a table. But again, the clarity, the precedence diagram does not give this table. So we have to make that. And in that time and cost estimates are provided, because we calculate on the basis of that, that actually how much time it will take to complete this project. We will calculate the longest path, which we call critical path, that which activities are being called in this critical path. And if we have to complete the project quickly, then what are the activities on which we put our resources. Only those activities, which are falling on the critical path, will only benefit from putting extra resources in them. Because by putting resources on them, the time of activities will be reduced, then the time of the critical path will be reduced. And critical path is the one which determines how much time the project will take. So if there is no activity on the critical path and you will put time on it, you will put resources on it to reduce the time, then there will be no benefit of it, the time of the project will not be reduced. So in this, this is the plan, schedule, monitor and control project based on network design. Because this is in front of us, what are the activities, what is the relationship and how we have to monitor it, what is the activity first, then what is happening and so on. And on that basis, this network design becomes very important.