BCGBC4007A Plan building or construction work

Develop, track and revise project timeframes

Network systems or PERT charts
Activity - Choosing the critical path 
A diagram of a chart showing the task sequence for building a brick fence is describe below. This diagram is repeated from 'Durations on PERT charts'.
From node 1, the first task is 'Enquiries, orders'. Node 2 has three branches, one to 'Wait bricks' which leads to node 3 'Load bricks' then on to node 7. Also from node 2 is 'Clear site' then node 4, 'Dig trench' then node 5. The third task from node 2 is 'Order concrete' which also joins to node 5. The next task is 'Pour footings' then 
node 6, 'Footings curing' (three days) then node 7. The final section of the chart is 'Mix mortar and lay bricks' (one day) then node 8, 'Clean up' (one day) then the final node number 9. 
Starting from node 1, which of the paths are on the critical path?
A.     	Node 1 to node 2
B.     	Node 2 to node 3
C.     	Node 2 to node 4
D.     	Node 2 to node 5
E.     	Node 4 to node 5
F.     	Node 3 to node 7
G.     	Node 5 to node 6
H.     	Node 6 to node 7
I.     	Node 7 to node 8
J.     	Node 8 to node 9
The correct answer is A, C, E, G, H, I and J. The critical path is from node 1 to 2 to 4 to 5 to 6 to 7 to 8 to 9. 

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