Correct Answer - Option 4 : 1, 2 and 3
Independent float is the time by which starting or finishing of an activity can be delayed without affecting the total float of its proceeding and succeeding activity.
It does not affect start of succeeding activity i.e. following activity.
It does not affect latest completion of preceding activity.
It only affects concerned activity.
Mathematically, it is given by:
FID= total float – head event slack – tail event slack
Other type of floats:
1. Total float: It is the time by which starting or finishing of an activity can be delayed without affecting the schedule completion period of a project. It affects both succeeding and proceeding activities.
Mathematically, it is given by
Ft = LST - EST or Ft = LFT – EFT
EST = Earliest Start time
EFT = Earliest Finish time
LST = Latest Start time
LFT = Latest finish time
2. Free float: In this only proceeding activity is affected and it is given by:
Ff = Ft – head event slack
3. Interfering float: It is just another name given to head event slack.