Generally, PNs
(Precedence Network) do not events and dummy activities. However, there are few
exceptions. Where a PN starts (or ends) with more than one activity, its start
(or end) can be shown by a start event (or an end event).
In large networks,
connectors are used to separate part of a network or to provide logical links.
Further interface in the form of dummy event can be introduced to mark
overlapping of sub networks. The connectors and dummy events of are shown in
fig.
(a) Use of dummy event
to link multiple activities, where logic permits so as to avoid congestion.
Dummy events can be drawn as boxes or circles.
(b) Use of connectors to
separate parts of networks.
Network Presentation
Some more points for
improving the presentations for making them more readable and acceptable:
1.
Make the text of
activity description brief but significant. Avoid describing activities by
using non-standard abbreviations or alphabetic or numerical codes like A, B, C,
0-2, 5-9, etc. as they need frequent reference to a list of legends.
2.
Draw information index by
stratifying the network into broad horizontal and/or vertical bands for
demarcating departments and grouping similar type of works.
3.
Use the drawing method
specified for writing titles of network, drawing number, sheet number, revision
data, names of persons drawing and approving the network, date of issue, and
the signature. Notes on network-drawing should highlight the unit of time, the
non-standard symbols used and other important drawing features including
distribution. Generally, all this information is written on the right hand side
of the drawing sheet.
