Question

The City Commission of Nashville has decided to build a botanical garden and picnic area in the heart of the city for the recreation of its citizens. The precedence table for all the activities required to construct this area successfully is as​ follows:

                                                                                 

Code	Description	Time ​(hrs)	Immediate​ Predecessor(s)
A	Find​ location; determine resource requirements	20	None
B	Requisition of lumber and sand	65	A
C	Dig and grade	95	A
D	Saw lumber into appropriate sizes	35	B
E	Position lumber in correct locations	25	​D, C
F	Nail lumber together	15	E
G	Put sand in and under the equipment	20	F
H	Put dirt around the equipment	15	F
I	Put grass all over the​ garden, landscape, paint	25	​G, H

Refer to the legend for the activity that corresponds to each code.

Using the line drawing​ tool, draw a Gantt chart for activities E through I of the project.

Answer 1

ACTIVITY	DURATION	ES	EF	LS	LF	SLACK
A	20	0	20	0	20	0
B	65	20	85	20	85	0
C	95	20	115	25	120	5
D	35	85	120	85	120	0
E	25	120	145	120	145	0
F	15	145	160	145	160	0
G	20	160	180	160	180	0
H	15	160	175	165	180	5
I	25	180	205	180	205	0

FORWARD PASS

We calculate the ES and EF values using a forward pass where the ES of an activity is the maximum EF of all the predecessor activities.

BACKWARD PASS

We calculate the LS and LF values using a backward pass where the LF of the activity is the minimum of all the successor activities.

SLACK

Slack is the value which is determined by subtracting EF from the LF or ES from the LS.

CRITICAL PATH

Critical path is the chain in the project network where the slack value of all the activities is 0, what this means is that any delay in these activities would result in delaying the entire project.

CRITICAL PATH = ABDEFGI

DURATION OF PROJECT = 205

GANTT CHART 20 95 ACTIVITY 15 15 25 0 50 100 150 200 250