Critical Activities

Activity is critical if its delay will delay project finish.

Trouble is, sometimes an activity's start may be critical but not its finish.  If A is a 15D activity and a SS+5 predecesor of B (on the CP), then a delay in the first 5 days of A will delay the project completion, but a delay in the final 10D of A won't (if it has Super Float). 

Fraternally in project management,

Steve the Bajan

Frndz,

I still didn't got what i want,

can anyone help me in detail.

Hi Mohd,

what details do you need?

Activity is critical if it has no time reserves for its execution. Delay of critical activity execution delays project finish or major milestones where Finish No Later Than is defined.

Any PM software finds critical activities when resources are unlimited. These activities have zero (or negative) total floats (Late and Early dates are equal or Late dates are earlier than Early dates). 

When resources are limited finding critical activities is much more complicated and most PM packages produce wrong results (calculate wrong total floats).

Hi

Steve : Did u mean to say that Delay time is the critical time ( critical path) , which extends the duration of project

Aijaz

Hi, Aijaz.

I'm not quite sure of your question, so let me answer it this way:

• Every project ALWAYS has a critical path (at least one!) of activity durations, constraints, and handoffs and other delays, which is the longest path.  This path determines the length of the project. Delays on this path make the project longer, while (and this is important!) reductions in time on this path will make the project shorter UNTIL another path becomes the longest path.
• The respective activity durations, constraints, and handoffs and other delays on the critical path are each contributing various amounts of delay (depending on their durations, dependencies and location in the network) to the total duration of the critical path. This amount of time is each activity's critical path drag.

For a (MUCH!) fuller discussion with Miklos and Rafael, see the Critical Path Quiz discussion.

Fraternally in project management,

Steve the Bajan

Hi Mohd

A critical activity is any activity that (if delayed) will delay the overall project duration.

The string of critical activities (that join up through the project) is called the "critical path", and the total durations on this path defines the overall duation of the project

Activities that are NOT critical have "Float" (ie they can be delayed to a certain extent without delaying the overall project duration)

A critical activity might be taken off the critical path by making it shorter in duration by (eg) allocating more manpower, or using a faster work-method. BUT, if successful with this, the critical path will simply move to another path (or string) of activities.

There will always be a critical path somewhere !!

Kind Regards

Stewart