QUESTION $4$

$(20$ Marks$)$

The table below gives the duration estimates in days for a construction projection.

$\backslash$table$[[$Activity$,$Predecessor,Optimistic,Most Likely,Pessimistic$],[$A$,-,2,4,7],[$B$,-,1,3,6],[$C$,-,3,5,8],[$D$,$A$,9,11,20],[$E$,$A$,2,5,7],[$F$,$B$,6,9,20],[$G$,$C$,5,10,22],[$H$,$E$,$F$,3,5,12],[$I$,$D$,4,7,9],[$J$,$G$,6,9,13],[$K$,$H$,$J$,3,4,6],[$L$,$I,K$,7,10,23]]$

$4\mathrm{.}1$ Determine the expected completion time for each activity. Round off answers to the nearest whole

$(5$ marks$)$

number.

$4\mathrm{.}2$ Construct an Activity$-$on$-$node $($AON$)$ network for the activities of this contract.

$(5$ marks$)$

$4\mathrm{.}3$ Determine the critical path for the project by calculating the slack for each activity.

$(10$ marks$)$