Difference between PERT and CPM

It is the basically topic of project management .
Here  PERT and CPM are scheduling technique to analysis project network.
let us discuss about the difference between PERT and CPM.

                               PERT                                                 
1. full form is :
    programme evaluation review technique.

2. it is applied in new type of project, the project for which the data's are not available.

3. it is based upon probalistic  approach.

4. PERT is event oriented .i.e completion of a project depend upon the end result.

5. In PERT three time estimate are being done,
these are :
      a. optimistic time (to)
 it is the minimum time required for completion of activity when situation's are completely favourable.

     b. pessimistic time (tp)
  it is the maximum time for completion of activity when the situation's completely unfavourable.

    c. most likely time (tm)
      it is average condition ,here situation's are neither completely favourable not unfavourable.

In PERT , Activity duration follows "Beta distribution ".
based upon this type estimate the expected mean time for completion  of activity given by
           t = (to + 4 × tm + tp)/6 ;
basically you say mean project duration.

 6. PERT is control device.




                                 CPM

 1. full form:
                    critical path method.

 2. it is applicable for repeatedly project ,for which the data's are available.

 3. it is based upon deterministic approach.

 4. CPM is activity oriented.i.e completion of project take place in the form of completing the activity.

 5. here only one time estimated.

 6. CPM is planning device.


 thank you everyone.