The main purpose of the flow diagram is to
facilitate a systematic drawing of the draft of network. The guidelines for
converting the logic diagrams into draft network are:
a) The dummies should be reduced to minimum.
b) The crossing of arrows should be avoided
by a suitable re-positioning of the activities.
c) The new activities should be incorporated,
if visualized during the preparation of logic diagrams.
d) Logic of all the activities should be
verified for its correctness.
Structuring Model Using Network Drawing Rules
The project networks are constantly read,
referred to and reviewed. Therefore, it is essential that they should be
suitably titled and numbered, neatly drawn by readable lettering printed
horizontally, and divided into strata for easy reference.
The various convention and rules for drawing CPM network are
given below.
a) All arrows must run from left to right.
Turning arrows in the reverse direction is not correct.
b) The arrows should have sufficient
horizontal length so that a description could be written over it.
c) The crossing of arrows should be avoided
by suitably re-positioning them.
d) Arrows running close to each should be
avoided. The intervening space should be sufficient to permit writing of
activity description.
e) The concurrent activities (commencing and
terminating into common events) should be separated by inserting additional events
followed by dummy activities.
f) The activities emerging from an event
should takeoff from a line rather than a point. Similarly, activities
terminating into an event should finish into a common line.
g) Wherever possible, the network should be
drawn in such a way that activities belonging to the same strata can be
demarcated by drawing vertical and/or horizontal lines.
h) Use of large sheets should be avoided. If
required, a large network can be split into two or more sheets having common
interface events. For easy recognition, the interface events can be represented
by double circle or ellipse.
i) The network should be re-drawn, if
necessary, to give a neat appearance.
j) Print of important networks should be
taken and circulated to all concerned for comments. Amendments should be
carried out, if necessary.
