So let’s take another one more example also to highlight just to quickly the relation between the finish to finish relationship. So, if we have the exactly same example from example number 4 of activity x, Activity y, and activity z. But the relationship between all three in this case will be a finish to finish relationship And if we have the same, Durations. So the way we calculate the early start. The first activity we have, early start of 0, 0 plus 9 equal 9. Then the relationship between x and y is a finish to finish relationship. So the constraint here is we take the 9 to y to place it as the early finish day of activity y. However, and let's move forward, I will stop here quickly later. For z it's going to be the same thing, a finish to finish relationship and we'll have also an early finish date of 9 because this is a finish to finish relationship as explained here, as shown here in the logic diagram. Now, the early start date for activity y will be, someone might say, 9 minus 4. But because there is no predecessors of activity y, and this consider as one of the beginning, then we can start as early as 0. The same thing will go for z, there is no predecessors that are connecting the start or constraint the start of activity z. And there is no constraint to highlight or put the logic with the early start or the start of activity y. That's why we could have them as 0. So again, the total then duration of the project will be 9 because the longest is 9 days. Then we would have a 9 as a late finish for all the three activities. And the late start is 9 minus 2. 7, 5 and 0. So if we do have, It change a little bit in this example, and have a duration of y equal 11 days instead of 4. What's going to happen here is y has no control on its predecessors, But has control on its successors. So when we take the 9 as a finish to finish relationship, the more constraint that we will follow is the duration of the activity itself which is 11 days. So in this case, the 9 will be 11 and the total duration of the project will be a total of 11. So in this case, the 11 here will go to the 11 because y has control on its successors. So in this case, activity z, the early finish date has to be 11. And that's will lead that late finish date for all the activities to also be 11. Because the duration of the entire project will be 11 days. And all of them need to finish around the same time. So the latest we can go is the total duration of the project, which will lead to a late start date for z to be 9, 11 minus 2. For y to be 0, 11 minus 11. And for x to be 2, 11 minus 9 equal 2. So what we covered so far then as we saw here from all these examples, more and more focus that given to the finish to start relationship. In the modules before, if you remember we highlighted that most common relationships, especially in the module focusing on the types of relationships that we have in construction industry, we focus more in the finish to start as a traditional or finish to start plus lag. Or we have start to start relationship and finish to finish relationship. For the sake of this course, we will not go into more examples related to a multiple relationships. And I deliberately focused more on a simple example when it has lag or it has different durations and constraints between start to start relationship and the finish to start relationship. Most schedulers we have in the industry, they do prefer to go always to the the finish to start relationship, sometimes of course with the lag time, that's why I highlighted an example with the lag. For the start to start and finish to finish, I encourage you if you like to read a little further more. If you have to go through that, we give you a quick, simple examples to understand the concept behind it. Thank you.
