Correct Answer - Option 3 : Expected time of both activities A and B are same
Concept:
(i) PERT is based upon probabilistic approach in which three time estimate are made for each activity i.e. optimistic time, most likely time and pessimistic time.
(ii) Based on these three an expected mean time is computed which is weighted average of above three time.
\({t_e} = \frac{{{t_o} + 4{t_L} + {t_p}}}{6}\)
where, to = Optimistic time
tL = Most likely time
tp = Pessimistic time
Calculation:
For activity A:
Given, to = 4 week, tL = 6 week and tp = 8 week
∴ Expected time for activity A, \({t_e} = \frac{{{t_o} + 4{t_L} + {t_p}}}{6}\)
⇒ \({t_e} = \frac{{4 + 4 \times 6 + 8}}{6} = 6\ week\)
For activity B:
Given, to = 5 week, tL = 5.5 week and tp = 9 week
∴ Expected time for activity A, \({t_e} = \frac{{{t_o} + 4{t_L} + {t_p}}}{6}\)
⇒ \({t_e} = \frac{{5 + 4 \times 5.5 + 9}}{6} = 6\ week\)
Hence Expected time for both the activity is same.