 Myself Satish Tharangi, Assistant Professor, Department of Civil Engineering, Walsh and Instruct Technologies, in today's session, we are going to see regarding the floors of the activities which are required for the project management. At the end of the session, the particular learner will be able to find out the floors associated with the activities and their use for the project management. Now let's see the particular floors of the activities. It is a flexibility range of the time available with the activity by which particular activity can be delayed without affecting the overall project duration. And it is a difference between the particular activities times here the it is a difference between the latest starting time and the earlier starting time that is the latest starting time and the earlier starting time and the latest finishing time and the earliest finishing time of which we have to define the float. There are three, particularly when we observe there are four types of floors that is a total float, free float, independent float and the interfering float. Now let's see one by one. The total float, a total float is a time span available with the activity by which the particular activity can be delayed without affecting the overall project duration. The formula for the total float is nothing else as we have seen that is for the earlier slide that is latest starting time minus earlier starting time or you can say latest finishing time minus earliest finishing time. Let's see the example of activity A. Here the latest starting time of the activity A is 0 and the earliest starting time is 0. So 0 minus 0 we get the 0 value and the latest finishing time is 3 and the earliest finishing time is 3. So 3 minus 3 it's 0. As we see that the particular value of total float is 0 means the activity A is the critical one. If the values of the total float or it's a float of the activity is more than 0 then the particular activity is a non-critical one. Now the free float, the free float is a time span by which the activity can be delayed without affecting this exciting activity and it is a portion of the total float. Here the formula for the free float is here. It is the earliest starting time of a succeeding activity of the selected activity of which the free float is to be determined minus the earliest finishing time of the activity of which the free float is to be determined. Now let us find out the value of activity A free float. Free float of activity A is equal to EST of activity B minus EFT of activity A. EST of activity A is and we have to see the EST of activity that is a succeeding activity that is B activity that is 3. 3 minus 3 it is equal to 0. Now independent float the independent float is the excess time available if the preceding activity N as late as possible and the succeeding activity start as early as possible. Now let's see the formula for the independent float. The independent float formula is EST of succeeding activity of selected activity of which the independent float is to be determined minus LFT of the preceding activity of the selected activity of which independent float is to be determined minus the activity duration of which independent float is to be determined. Here let's see the example the independent float of activity B. Here for the activity B the succeeding activity C and the EST of particular activity C is 5. So EST of activity C minus that is 5 and the LFT of activity A as a formula is what? LFT of preceding activity of selected activity. The selected activity is B and its preceding activity is A. So LFT is 3. So 5 minus 3 here I have mentioned 5 minus 3 and the activity time of which the independent float is to be determined that is B activity is active time is 2. So 5 minus 3 minus 2 that is we are getting 0. In this way we can determine the independent float for the activity C as well as for activity A by assuming the succeeding activity for C and the preceding activity for A. Now the interfering float. The interfering float is the difference between the total float and the free float. It is equal to the head event slack. The interfering float for the activity A is the total float that is value is 0 and the free float value is also 0 because presently the activity A is a critical one. Now let's clear our particular question by taking an example. This is an example in which there are particularly 5 activities and this is a network diagram which is showing you the event times as well as activity times. Here let's see the particular example duration as well as here the duration of the activity or you can say project is 10 and the particular let's find out the critical path. Now how to identify the activity is critical or non-critical that can be identified by using the floats of the activity. In this slide the particular table which is showing you the activities and its activity times with the total floats free float, independent float and the interfering float. Now let's see the all type of floats for activity A. The total float the formula for the total float is what LST minus ESC that is 0 minus 0 we are getting a total float as a 0. Now free float the free float is nothing else EST of succeeding activity. For activity A there are two succeeding activity B and C. Let's see the EST of activity B and C that is 3 and 3 minus the EFT of activity A. So 3 minus 3 it's 0 and 3 minus 3 you can see it's when we are considering the C activity is 0 and the independent float the independent float is nothing else. It is a particular float which can be determined by using the activity times of the succeeding activities of activity A as well as preceding activity of the activity A. The succeeding activity the ESTs of the succeeding activities 3 and by assuming the preceding activity of A as something else the particular LFT will be 0. So 3 minus 0 minus 3 we get the independent float of the activity A as a 0. Similarly the difference the interfering float is nothing else the difference between the total float and the free float. So 0 minus 0 we are getting 0. Here a particular activity A have all type of floats as a 0 value because this is activity which is one is a critical one. So the critical activity which should start as as per defined and should finish as per the defined time. Now activity B okay this is a activity which is a non-critical one. How to identify? The particular LST of the activity B is 5 and EFT is particularly 3. 5 minus 3 we are getting 2. Means the total float for the activity B is 2. Means what this particular activity can be delayed by today maximum today without affecting the overall project duration. Now let's see the particular free float of activity B. The free float for the activity B that is succeeding activities D. So EST is 5 minus EFT is 5. 5 minus 5 is 0. Means for the particular activity B there is a 0 free float okay and the independent float is also 0 but the interfering float is 2. Now the total float minus free float that is 2 minus 0 we are getting 2. Similarly we can determine for the activity C. Yeah again we are observing that activity C is a critical one okay. The red killer is highlighting that the particular activities are critical one. So we are getting the value of the particular activity C's total float is as 0, free float as 0, independent float as 0 and the interfering float as a 0. Similarly for the D activity here the D activity is a particular activity which is a non-critical one. So you are observing that the total float the total float is 7 minus 5 that is LST minus ES that is 2 and the free float is nothing else it's value also to how if I consider some activity succeeding to the event 5 then its particular EST will be the 10. 10 minus 8 it's 2. So the particular D activity have the total float is equal to 0 2 as well as free float is equal to 2. So the independent float for the activity D is 0 and the interfering float is has also 0. Similarly for the E activity when we observe it is having as it is a critical one all the floats are equal to 0. In this way we can determine the float associate with the each activity as well as float types for the each activities. Now let us select the correct answer for the particular questions. Hope so you have selected the correct answer as been mentioned in this slide and these are the references for the today's session. Thank you.