compute activity slack, and identify the critical path.

How long will this project take? How sensitive is the network schedule? Calculate the free slack and total slack for all noncritical activities.

$\backslash$table$[[$ID$,$Description,Predecessor,Time $($days$)],[$A$,$Systems design,None,$2],[$B$,$Subsystem A design,A$,1],[$C$,$Subsystem B design,A$,2],[$D$,$Subsystem C design,A$,1],[$E$,$Program A$,$B$,2],[$F$,$Program B$,$C$,10],[$G$,$Program C$,$D$,3],[$H$,$Subsystem A test,E$,1],[$I$,$Subsystem B test,F$,1],[$J$,$Subsystem C test,G$,1],[$K$,$Integration,H$,$ I, J$,3],[$L$,$Integration test,K$,1]]$