Question

In a manufacturing company a project with six activities is going on. The three time estimates for each activity are given below.
Which of the following is the critical path for the given project?
$$\begin{array}{cccc}\text{Activity}& t_o& t_m& t_u\\ 1-2& 2& 4& 6\\ 2-3& 2& 2& 2\\ 3-5& 4& 7& 10\\ 5-6& 3& 4& 5\\ 1-4& 7& 8& 9\\ 4-5& 4& 5& 6\end{array}$$

• A. $1-2-3-5-6$
• B. $1-4-5-6$
• C. $\text{any of the (a) and (b)}$
• D. $\text{(a) and (b) both}$

Answer 1

The correct option is A $1-2-3-5-6$

${\sigma }_2=\frac{1}{\sqrt{3}}=0.557days$

Project duration for both parts is same but standard deviation of project for path $1-2-3-5-6$ is more.

So path $1-2-3-5-6$ will be the critical path.

$\text{Critical path = 1 - 2 - 3 - 5 - 6}$