Latest start of an activity is always

Below we have discussed the Activity Times in CPM:

• Earliest start time (EST):

(i) It is the earliest possible time at which an activity can be started. For activity i – j, the earliest event 

time of the event I, i.e., TEi, is EST of activity i – j.

• Earliest finish time (EFT):

(i) It is the earliest possible time by which an activity can be completed.

For an activity i – j,

EFT = EST + tij

• Latest start time (LST):

(i) This is the latest possible time at which an activity can be started without delaying the overall project.

∴ LST = LFT – Activity duration

(ii) LST of an activity is to be calculated on the basis of the latest occurrence time of its head event and not based on the latest occurrence time of its tail event. So, the Latest start of an activity is always greater than or equal to the latest event times of all the preceding nodes

• Latest finish time:

(i) This is the latest time by which an operation or activity must be completed without delaying the project.

For an activity i- j, the latest allowable time of head event j, i.e., Tij, is the LFT of activity i – j.

Summary:

The latest start of an activity is always (A) greater than or equal to latest event times of all the preceding nodes (B) less than or equal to the earliest event times of all the preceding nodes (C) equal to the latest event times of all the preceding nodes (D) equal to the earliest event time of all the preceding nodes

The latest event times of all the previous nodes are always greater than or equal to the latest start of an activity. Apart from this, all the options are incorrect.