Free float is the duration of time, that an activity can be delayed without delaying the projects estimated completion time and without delaying the. Ftse russell guide to calculation ftse global equity index series, v3. Activity chains total float total floats of activities on an activity chain are the same. For example, you estimated to finish an activity in 10 days, but due to an upcoming festival, you have to finish it in five days. The purpose of the forward pass is to determine the early start top left. The video starts with 3 terms total float, free float, and negative float. Where as free float is defined as the number of units the start of an activity can be delayed without delaying the start of successor activity. Today, i am going to tell you about free float and total float. Im often asked the question about the differences between total float tf and free float ff. For better understanding, lets analyze a simple total float and free float example. Please refer to the following link where the difference between free float and total float is given. Variance the difference between the current and target schedule dates. Im also attaching a downloadable pdf file that illustrates the two concepts using a network diagram. How to calculate float, free float, total float using es.
Total float is the amount of time that a schedule activity can be delayed from its early start date without missing the project finish date or violating any schedule constraints. The calculation of free float in a pdm network is more complex. Understand the difference between total float and free float in critical path method according to pmbok guide with the help of a network diagram example. Total float and free float refer to the amount of time, or scheduling flexibility, that exists associated with activities on the project schedule. Total float is the total amount of time that a schedule activity may be delayed from its early start date without delaying the project finish date, or intermediary milestone. Introduction to the interfering float activity floats. The time the activity can be delayed without delaying the end of the schedule. Critical path method schedule analysis total float calculation. For more resources for the exam, visit our site courses study materials. Free float time period of potential activity delay that does not cause a delay of any other activity in the project schedule.
That being said, traditional network diagramming techniques use the total float, so project management is normally based on the total float, while free float is not used unless it is necessary. In fact, i was also planning to draw a network diagram where you can see that the total float and free float are different but in that case, calculation will little lengthy. Assume that, we made forward and backward pass calculation and determined the critical path of the below network diagram. I covered concept to calculate the total float and free float in this example and i hope once you understand it, you can calculate them in any scenario. A company has 5 million shares outstanding in total, with 1 million of them in a lockedin.
In primavera, you can choose between 3 options to calculate total float. Free float what is the total float and the free float for activity f and j. Total float versus free float in scheduling projectcubicle. Free float early and total float can be calculated.
Now calculate total float of an activity using the following steps. Rating is available when the video has been rented. Project float vs total float dedicated to project controls. And in this example, we will go also through total float and free float calculations quickly. In primavera p6 eppm both total float and free float may be tabulated and displayed directly on the gantt chart for quick analysis. The importance of calculating total float and free float are found it the definitions of these terms. Project float is the total amount of time that the project can be delayed without delaying the project completion date required by the customer. Let us understand the floats with the help of a small example. The free float measures the spare time available on a single activity, so that there is no delay on the start of the following activity, i. By default float or slack actually means total float total float. The easiest way to calculate critical path, total float, free float, early start, early finish, late start, and late finish. Learn about formulas to calculate total float and free float. Calculate float, total float and free float in network diagram. What is the difference between float and free float.
Example if activity 1 has a duration of 6 days and is occurring concurrently with activity 2 which has a duration of 9 days, activity 1 has 3 days of total float. The float calculations for the sample schedule are shown in exhibit 5. Heres a post explaining the difference between the two, with an example. Many calculation type pmp questions are pretty straight forward. This is what the free float calculation formula looks like. The formula used to calculate free float is different for these two situations, however, the result is the same. Just wondering the 1 case, as how the difference calculation between free float and total float has come in. The formula lses, you are referring to, is for the total float. What is the difference between total float and free float. For each activity, it is possible to calculate two float values from the results of. Determining total float and free float activity floats. Check out for more free engineering tutorials and math lessons. When i was preparing for my pmp exam, i was very confused about the difference between total float and free float in critical path method cpm.
The time the activity can be delayed without delaying the end of the schedule or an imposed constraint. Therefore, free float is computed by subtracting the lockedin shares from outstanding shares. How to calculate float, free float, total float using es, ef, ls and lf. Total float activity n late start activity n early start activity n. After some research in the oracle knowledge base document id 988077.
Total float and free float for an activity may be the same or different depending on the other activities in the schedule diagram. Total float tf the total number of days that the start or finish of an activity can be delayed without affecting the project finish date. Learn how to calculate total float, free float, float or slack by example. All you need to know is the right formula, and have a good understanding of the basic concepts to apply the formula in the right way. The choice of the calculation method can affect the calculated total float. Free float in the context of project management, the term free float is used to describe amount of time that spans from total quality management tqm total quality management tqm is a project management technique or strategy that is implemented to assure. When you are asked to calculate the float for an activity in the pmp exam, you are asked to calculate the total float. In this tutorial we will be discussing only the total float.
Free float is only calculated on the last activity in an activity sequence. Having the same equations just as a reminder for the total float and the free float, please go ahead and try to calculate in this example the total float and the free float for a minute before we go move forward with the solution. The three tasks highlighted in by the red circles figure 4 determine the free float for task a and define. In primavera p6, total float can be calculated by one of three methods. It may be observed that the total float of activities lying on critical path is zero. Total float is very important in critical path method calculation, total float is the amount of time which an activity can be delayed without delaying the project end date. In the first part of the series, i talked about the three point estimate questions. The objective of the forward pass and backward pass is to allow the float to be calculated. Stocks with small free float tend to be more volatile because there are only a limited number of shares that can be bought or sold in the event of major trading news. Click on the figure to download the network diagram as a pdf file. In project management, float or slack is the amount of time that a task in a project network can be delayed without causing a delay to.
Total float represents the amount of time an activity can be delayed without delaying the overall project duration and is also called float or slack. The total float and free float of an activity may not always be the same number of days. In this page we describe the third part of arrow diagram calculations, the float calculations. There are various other types of float independent, early free, early interfering, late free, late interfering, and float can also be negative. Critical path method calculations project schedule. Calculation of total float tf, free float ff youtube.
Learn how to calculate float in project management. Free float is a more stringent measure than total float. Total float is calculated by detracting early dates from late dates. Thus, tf of q and e equal to tf of w according to ms3. It also talks about network diagram and critical path method cpm. Critical path method schedule analysis guide milestonetask. Float may occur when there are two or more activities happening concurrently. As stated earlier, float values indicate how much each individual activity can be delayed before affecting successor activities or the planned project completion date. I have written this article to explain the difference between total float and free float in critical path method cpm. What we have here, the total float and the free float. Lets take the project of exam study and preparation as an. The free and total float times are the amount of scheduled leeway allowed for a network activity, and are referred to as float or slack. Total float, free float and independent float explained.
Total float and free float refer to the amount of time, or scheduling flexibility, that exists. If a project network chartdiagram has 4 noncritical paths then that project would have 4 total float values. Guide to calculation ftse global equity index series. Project float is the total amount of time that the project can be delayed. Simple formula questions part 2 calculating float pmchamp. Pdm network with total and free float calculations. We shall not go into these situations at present for the sake of simplicity and be concerned only with total float for the time being. When an activity has zero total float, free float will also be zero. Lets take an example to see how to calculate free float. The calculation of total float in a pdm network is contained within the activity and is basically the.
For the same reason, companies with larger free floats are generally less volatile. Total float activity n late finish activity n early finish activity n. Updating the process of recording progress in a project at regular intervals. Your logic needs ten days, but the constraint is not allowing you to go beyond five days.
Critical path method schedule analysis free float calculation. We discuss three types of floats in this video viz total float, free float and independent float with examples. Computation of total float, free float and independent float. Theory and problems now with oreilly online learning. Some setting or calculation in primavera p6 was clearly off. But, i want to advance in this example, and give you more of interpretation and introduction to another type of a float other than the total and the free float. The calculation for free float ealy start successor early finish predecessor is unaffected, as this constraint type only impacts on the late dates. Early start, early finish, late start and late finish calculation with example duration. A companys free float is important to potential investors because it offers insight into the companys stock volatility. This is really a long post, to cover various calculation such as float, total float, free float, early start, early finish, late start and late finish using the forward and backward pass.
1002 1052 809 332 765 1348 1363 548 1252 1279 874 253 1 1213 828 228 1139 152 1487 183 294 1363 1383 769 885 1031 1112 1298 1193 687 1406 307 1000 528 514 1073 1008 1024 29 883