That being said from the quick overview, I would like to go through couple of recommendations on how you draw or build an activity on node or precedence diagram. First, the construction activities in the activity or node diagram or the precedence diagram, are preferably to be drawn as rectangles or squares. You try as much as possible to avoid drawing them as circles, sometimes you can do, but it's highly preferable to have it as a square. And I will tell you more details for other modules about examples on that. And why we're trying also to avoid the circles because activity on aero, which is another scheduling tool that we'll be learning during this course. We use the circles as nodes between the activities which represents by arrows and I will leave that for a later time. So, focus on how to draw each activity as a rectangle or a square. Second, we highly recommend to do not connect from the top or the bottom of the construction activity of that square. Try just to focus on their sides only. For example, we have activity A here. Don't go from the top of that activity, so as you can go and connect it to another construction activity. You try to make it from the side of the activity instead. Also, another example from the bottom point of review, if we have activity B, we want to connect the arrow to, try to avoid connecting it from the bottom here or even the top of the activity. It's highly recommended to go on the side, as it went out from the side in that activity here. Another recommendation, is when you're building your activity on node, don't combine relationship lines, the arrows. For example, let's say we have three construction activities, A, B and C. And Activity B and C depends their starting on finishing Activity A, as we can see here. So, the connection we put here between the two lines, it's overlapped. This is highly not recommended to be done. And the way how to overcome that is to split into two lines to highlight both relationships. And the reason why we highly recommend to use this one, not this one, is the lag. Because some of these activities, let's say, for example, activity B, might have a lag time with activity A of one or two or three days. However, activity C, let's say, has zero lag time. So, if you put the number here as lag, you will be confused on which activity B or C has the lag refer to. Another recommendation, is to design from your activity on node diagram from left to right in an almost, do your best, chronological order. What I mean by that? So, let's say, we have activity A and we noticed in the back is activity B, which will be following activity A. So, one way to do that is to go from right to left in the arrow and connect the two activities. This is not recommended. So, the way to do it, is to have activity A drawn first, and then activity B, so as you have the line showing the logic relationship between these two activities. Also, of course, you can draw the line in step point of a view, step line or if you want it a little bit tilted line, it's all okay. Another recommendation, do your best to minimize what we call the line crossing in your network diagram. I'll give you an example here. Let's say, we have four activities, A, B, C and D. And let's say, activity D will not start until activity A, well, finishes, so we can draw the line to represent this logic relationship. And the same thing goes for C, it will not start until activity B, well, finishes. With line to show the logic relationship. Now, you might come and say, okay, wait a minute. What I can do to solve this, is I can redraw the four activities and have activity A here and activity B on the top. I will say, that's correct because you will avoid any crossings. But sometimes when you have more and more activities, you might be in a situation that you have to have a crossing between the lines. So, in case you have a situation like that, it's highly recommended to show it with the following. You put one of the lines and the other line you have a small kind of curve that's stepping above the crossing line to present the relationship or the logical relationship in that situation. So, do your best when you build your activity on node diagram to minimize any line crossings and if you have that, try to use this approach. Last one. Start And finish your construction project with only one node. So, let's take an example here. Let's say, we have a project, smaller project that contains six construction activities, as we can see here, from A, B, C all the way to G, E, F and G. So, these six activities, let's say, they have the following logic relationship between all of them. It says that, when activity A finishes, activity E will start, when activity A and B finishes, activity F will start. When activity B and C will finish, activity G can then start. So, here we have a simple project, we can present it. The recommendation here is, when we look at the starting of a project, it might get confusing on which the first activity's going to start. Despite the idea or the fact that we can see that these, all the activities, are going to start, it is highly recommended to have one node in the beginning. You can put it as a rectangle or square or even in this specific node, you can put it as a circle or even a diamond, if you want. The more practice that we can see in the literature and in the field, they are more towards the diamond shape. And you can name it, Start, or you can name it PS from a Project Start. And not only that, after you put that first node, then you can draw your arrows to highlight the relationship that after the start of the project, we have three prod three construction activities going to start when we head and start executing that project. The same thing what I mentioned, you start with one node, you finish, also, with one node. And here, the same concept, we draw towards the end of the project instead of having all these three activities open, with not connected with only one node, to have one rectangle or a diamond-shaped or a circle, saying the word, End. Or you can use the word let's say PE, Project End or PF, Project Finish. And the same concept what we highlighted with the arrows here, you do the same of connecting all that last activities in your projects, in arrows to the last node that highlighting a project finishes or a project ends. So, an advice here, sometimes you do have a lot of good, well developed softwares, like, Primavera, and Microsoft Office, a project that will help you develop all these networks, and diagrams, between your construction activities. But what if, you have a situation that you need to draw your activity on nodes and you want to highlight it and we will go through examples on that. My recommendation for you is, when you hand draw the network, you will need to redraw the network after the first attempt. Maybe, the first attempt logically is correct, however, it may look very confusing, especially, when you have good number of construction activities. Redraw the network to minimize, for example, any crossings that I told you about. And the good practice also to relocate the construction activities or the rectangles to be closer to their predecessors and successors.
