Question
Ross Kim
Geotechnical engineer
Asked a question 2 years ago

In construction Project, What is the meaning of the term Float?

In construction Project, What is the meaning of the term Float?

Where am I?

Float is a spare of time for a particular activity

Some activities have some time to lag it without affecting whole project duration time that’s call float of that activities

See the figure to better understand

Activity A to F have zero float that means if activities between A to F lag then whole project duration maybe change

Activity G and H have some float which means we can lag G & H activities up to its float without affecting whole project duration.

It is the amount of time which can be delayed

Seth Morgan
Construction Superintendent

In a construction project, the float is the amount of time that an activity in a project can be delayed without affecting the project completion time. For example, if A, B, and C are three activities/tasks with an estimated completion duration of 5, 8, and 6 days respectively, such that activities A and B can be done in parallel. In contrast, activity C can only be started after the completion of task A and B.

Now, we can see that task C can only be started eight days after the commencement of the project because B takes eight days to complete. But task A can be completed in 5 days, so it can be delayed by three days and still can be completed along with task B without disturbing task C. Thus, task A is said to have a float of 3 days.

The term float is used in project management, and it means the time difference between the early start of construction activity and the late start of the activity.

There are two types of float.

1. Free float
2. Total float
Flenn Hale
Construction Manager

In Construction Management or Project management, the float is an amount of a time an activity can be delayed without having a subsequent effect on the other activities and delayed in the project completion date.

Total float is directly related to the path.

Theodore Ray
Planning and development surveyor

In construction management, the float is defined as a difference between the early start and late start of construction activity.

Float is a delayed in time for a particular activity in construction, without affecting the deadline of completion of the project.

Suppose P, Q and R are three activities scheduled to complete in 10,15 and 20 days, respectively. C should be started only after completion of A and B.

P and Q be done parallel, then 15 – 10= 5 days are called ‘Float’.

In the float period, all labor strength focuses on working activity.

In construction management, the float is the available time for which an activity be delayed without delaying the total project duration while working on the Critical Path Method for scheduling.

You can use the following formulae for finding float in general.

Float = Time Available – Time Required

There are majorly two types of float. They are:-

1. Total Float
2. Free Float

Total Float is the excess time available to an activity without affecting the project duration.

Total Float of an activity = Late Start time – Early Start Time or Late Finish Time – Early Finish time

Free Float is the excess time available to an activity without affecting the early start of the succeeding activity.

Free Float = Early Start – Early Finish

While most of the time these two types of float are extensively used, there are two other types they are

1. Interferring Float – It is the amount of time available to an activity to delay its early start time, without affecting the project duration.
2. Independent Float – it is the available time for which an activity can be delayed without affecting the early start of the succeding activity and the allowable delay of any precedding activity.
Steve Mendoza
General practice surveyor

The term float, alludes to the gross time between the early and the late start of the project, without -vely impacting the gross critical time of the project.

Every construction has a date that is the most punctual conceivable time that project can start. For instance, the shingles on the rooftop, can’t begin until a portion of the rooftop sheathing is introduced. The sharp and experienced schedulers understand that the genuine shingles could initiate preceding the full fruition of the rooftop sheathing. This would be distinguished as the ambitious beginning of this thing, the most punctual date feasible for this work thing to start.

However, scheduling the proper timing for the early start requires an understanding of the construction process, to accurately identify the quantity of sheathing that should be installed, prior to the commencement of the shingles. Excessively small and the shingle positioning will get with the sheathing and should stop, an excess of sheathing establishment, and the schedule won’t be expanded for effectiveness. The administration and comprehension of construction, float is imp to the best possible scheduling of any construction project.

Float can be a risky idea, because of the supervisors to comprehend the float idea just for their potential benefit, and permit it to be blamed, not to forcefully seek after the schedule. Some management personnel realize an item has significant float time, in this way, the significance of its initiation is weakened by the float idea. Float time is the place you can amplify the effectiveness of a good construction schedule, it isn’t, leisure time, to be blamed so as not to speed up the schedule.

Meaning of float in a construction project:

Simply we can define float as the requirement of time for the performance of an activity may be delayed without delaying overall project completion.

Float provides for flexibility in the contractor’s operation In project planning each activity has its own fluid values which are based on Central path method calculation With the help of graphical approaches, we can calculate the Central path method calculation related to float.

Whenever a project is supposed to be delayed then recalculation the schedule for obtaining updated float values for remaining activities is really very crucial.

Traditionally based on Central path method calculation, we can categorize float into the following four types:

1. Total float
2. Free float
3. Interfering float
4. Independent float

Thank you.

Raul Jimenez
Senior Project Manager

In construction project, float or slack is the amount of time that a task in a project network can be delayed without causing a delay to: 1.subsequent tasks ("free float"). 2.project completion date ("total float").