$9-6.$ The precedence relations and crew size required to complete a project are given in Table $9.$s For example, activity E$,$ which comes after activity C$,$ requires $10$ weeks for its complelion by a crew of six people.

$($a$)$ Construct an early start Gantt chart and identify the critical path.

$($b$)$ Calculate and chart the labor profile required to complete the project for both an early start and a late start schedule.

$($c$)$ Level the required labor as much as possible with the goal of completing the project within the time period specified in part $($a$).$

TABLE $9-4$

$\backslash$table$[[,$Activity$],[,$A$,$B$,$C$,$D$,$E$,$F$],[$Immediate predecessors,$-,$A$,$A$,-,$B$,$C$,$D$,$E$],[$Mode $1,2,3,5,3,2,1],[,$ Duration $($days$),0,9,10,6,8,4],[$Resource I required $($hours$/$activity$),5,6,5,9,6,3],[,$ Resource II required $($hours$/$activity$),5,,,,,],[$Mode $2,1,2,4,2,1,1],[$Duration $($days$),12,12,8,6,9,4],[$Resource I required $($hours$/$activity$),7,8,16,12,5,3],[$Resource II required $($hours$/$activity$),7,,,,,]]$

TABLE $9-5$

$\backslash$table$[[$Activity$,\backslash$table$[[$Immediate$],[$predecessors$]],\backslash$table$[[$Time$],[($weeks$)]],\backslash$table$[[$Crew$],[$size$]]],[$A$,-,4,4],[$B$,$A$,2,5],[$C$,$A$,6,3],[$D$,$B$,3,7],[$E$,$C$,10,6],[$F$,-,2,5],[$G$,$D$,5,6],[$H$,$F$,7,2],[$I$,$D$,$E$,$G$,1,8],[$J$,$H$,10,2]]$