So let's take it further up. We give two quick examples to highlight how we draw the activity on arrow. And how to length and then put the numbering for all the nodes in the project. And give an example what's the dummy activity and how to use it. And now I want to highlight the following example, which is a little bit bigger one and I wanted to step further up to highlight much more activities involved. I'm sharing with you here four columns. The first column is the activities that I want you to draw an activity on arrow 4 to highlight the relationship in the diagram for these activities. Second column, I'm showing as I used to show the predecessors. However, sometimes you do have some activities that you can tell, what are the successors or the followers of these activities as I'm highlighting in column number 3. And for this specific example, I'm going to solve it for you and go through that exercise. Using the third column, the followers, for the first time instead of the predecessors as we used to do it. And the last column, I'm highlighting the duration of each of the activities. The reason I'm highlighting the duration because I want to go through a couple of steps. The first step is to draw the diagram. The second is to numbering all the nodes. A third is to do a forward and the backward past calculations but for an activity on arrow, that will be a good exercise. Last but not least, to highlight what is our critical path for this exercise or this project. So before I move forward, I would love to ask you, before I go through the solution, to write this down on a piece of paper and do this exercise and then we can share our solution together. So try, start with only drawing an activity on arrow diagram for the following example. How would we solve that instead of writing it, I design it, to go through it one by one on your slides. And as I mentioned, I would try to follow up on the followers which is a third column here instead of drawing it using the predecessors. So, in the table, it highlight that activity ABC. They don't have any predecessors, and they have the followers. That said, then they are the beginning of my project. So as I explained, it starts with only one node and you build on it. So if we have this node as the point in time when the projects starts. We have activity A and activity B and activity C going out from that first node of the project. So activity A, it highlights that it has now look at the followers of D and E, so we can just draw two arrows going out from that ending node of activity A to highlight activity D and activity E. Also activity B here, the followers are three activities, G, H, and I. So, from activity B, the end node for activity B can have going out from activity G and H and I. Activity C, also the end node has only one successor or follower, which is F then we have activity F going out from the ending node of activity C here. Now as you can see in the table, we have activity D, the one above here. It has one follower which is J. So we can just draw an arrow and indent up with an activity of J. And then we have activity E, which is the one here next, has two successors, G and H. So what you can see here. G and H we already draw them, and they depend on B. So what I would do it, if I'm doing it in hand, I'm going to delete these two, G and H, move them forward, to be able to highlight the node with activity E. In this case, we have activity E. The two followers, as mentioned in the example, is G and H. And the space here, we can link it with a dummy activity. So in this case, G and H still they have a predecessors of B. But later when you look at the predecessors, they also have a predecessor of E because E, the two follower for them is G and H. Let's go back here. We said E has two followers, G and H. What if, if I draw the line of E, just take it out and put it from this node here towards this node here. In this case I can say the followers of E would be also G and H but if you draw the line like that, then you are having I as also a successor or a follower of E, which is not the case. That's why we presented the relationship to have a node by itself here and the dummy activity between the B ending node and the starting node of G and H. So next would be activity F here. In activity F, the follower would be which is already here. So again, if I want to draw F and move just the arrow all the way to starting node of I, then I can meet the requirement, yes, for the followers of I would, the followers of F would be I but, you are also adding to it that the follower of F, you are connecting G and H as well. Which is, this is not the case, so what would you do? I will moved then activity I towards here to start with activity F And represent the relationship that it used to be between B and I with a dummy activity as well. So still, the followers of I of F is I, but I'm not connecting F with Activity G and H if I put it in the node here. So that will leave us with what? Activity G has two followers, J and K. So J is above here and we have activity G here, and I want to connect it to J, and I have another new activity, i's K. So let's move the shape to the back a little bit like this. So this is the same exact diagram, what we have so far. But I moved G to get a little bit up here. And I have K and J. K, I can simply just use, K like that, which the end-node of G is the starting node of K. And for J, in this case here, I can have just a dummy activity to highlight this. So, why I didn't do the following? To move Activity G ending node to be here, so as the starting is J and then I just draw another activity which is K. I didn't do that because K, it does not have a predecessor of D. That's why I have K first draw, because has the predecessor of G here and then I drew the dummy activity to highlight J and K as the two followers of activity G here. So the last activity we have is H and we're highlighting in it two successors, or followers J and K. So we have J and we have K and we want to link H as these two activities also to be followers to H. In this case we can simply just do a dummy activity between the end node of H all the way to this point in time, that highlighting the start of K and J. So why I did the dummy activity? Because if I didn't do it and I just move the arrow of H all the way to this node, that will violate the rule that says that every construction activity, in an activity on arrow diagram has an IJ number, unique number. But if I have H starting with the same node, when G start, and finishes at the same node when also G finishes, that will not work. That's why we introduce a dummy activity to have a different node numbers, an IJ number for both activities G and H. The reason I said this is the last activity because in the table it show that the last three activities I, J and H, I'm sorry, I, J and K has no followers. So in this case, J, K, and I, or I, J, and K, they are the last three activities in our project, so we can link them all together as in one node, as we can see here. As we can see from the table that I just provided, even if you want to go through the predecessors or through the followers as I just did as a new practice to highlight not only building the network from the predecessors, but also build it through the successors, or the followers we have the network diagram looks like that. I want to admit that it looked a little bit messy. That's why similar to what I told you from the activity on node in the module, activity on node or the presence diagram. In this course, I would definitely redraw that and make it more neat as we can see here. So, I just rearranged it after you have the diagram in front of you, I have this happen so as to be able to understand it, and put it better to do the calculations for the forward and the backward past calculations, and do the critical path method identification for the critical path for my project. And of course, last but not least, to be able to identify the duration of the project that you have. So if I want to just quickly go through it, you would notice that all the predecessors are met, and all the successors or the followers are met in the diagram. So again, what I told you, or the previous couple of examples. I highlighted in each activity in the top of the arrow, the name of the construction activity, the bottom of the arrow the duration of the construction activity. And what's left as the next step as usually to number the nodes and I like to go through the vertical number horizontal but both are okay, then we have 1, 2, 3, 4, 5, 6, 7, 8, 9, we have 10 nodes in our project here.
