Positive and Negative float

Can anyone explain using examples how to calculate positive and negative float. Thanks in advance.

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Positive Float

Positive float means that there is more time available for an activity in the project schedule. So if that particular activity was delayed it will not delay the completion of the project as per the project schedule. Positive float activities are not on critical path .

Negative Float - results when the time difference between the late dates and the early dates (start or finish) of an activity is negative Hence when we say negative float it means excess time is not available for an activity so that activity must have to start before their predecessor activities complete in order to meet a target finish date in a project schedule else the project is bound to be delayed.

For instance, the schedule requires 10 days but you have a constraint or deadline of 7 days...meaning you have a negative slack of 3 days (-3). Lower scope, add resources, or increase required duration.

If you have a negative float in a project schedule, it simply means that the schedule cannot be used or you are delayed on the Project even before you have started the work.

Now with this understanding can you think of some practical examples ?