<P> In this diagram, Activities A, B, C, D, and E comprise the critical or longest path, while Activities F, G, and H are off the critical path with floats of 15 days, 5 days, and 20 days respectively . Whereas activities that are off the critical path have float and are therefore not delaying completion of the project, those on the critical path will usually have critical path drag, i.e., they delay project completion . The drag of a critical path activity can be computed using the following formula: </P> <Ol> <Li> If a critical path activity has nothing in parallel, its drag is equal to its duration . Thus A and E have drags of 10 days and 20 days respectively . </Li> <Li> If a critical path activity has another activity in parallel, its drag is equal to whichever is less: its duration or the total float of the parallel activity with the least total float . Thus since B and C are both parallel to F (float of 15) and H (float of 20), B has a duration of 20 and drag of 15 (equal to F's float), while C has a duration of only 5 days and thus drag of only 5 . Activity D, with a duration of 10 days, is parallel to G (float of 5) and H (float of 20) and therefore its drag is equal to 5, the float of G . </Li> </Ol> <Li> If a critical path activity has nothing in parallel, its drag is equal to its duration . Thus A and E have drags of 10 days and 20 days respectively . </Li> <Li> If a critical path activity has another activity in parallel, its drag is equal to whichever is less: its duration or the total float of the parallel activity with the least total float . Thus since B and C are both parallel to F (float of 15) and H (float of 20), B has a duration of 20 and drag of 15 (equal to F's float), while C has a duration of only 5 days and thus drag of only 5 . Activity D, with a duration of 10 days, is parallel to G (float of 5) and H (float of 20) and therefore its drag is equal to 5, the float of G . </Li>

Which of the following is not one of the basic rules to follow when developing a project network