[Qgis-user] network building tool

[Tim Michelsen]

Dear list,
I am looking for a tool or plugin that could help me building the basis for
an infrastructure network (e.g. eletrical grids, gas or water piping
network, etc.).

The areas I am working do usually not have a good topographic mapping basis
and no infrastructure.

Usually, I would have the coordinates of the nodes (e.g. substations or
pumping stations) as a result from a survey or data gathering from a provider.

In a next step, I would need to build a network.

This be all done manually:
1) digitise the nodes
2) digitise the lines interconnecting the nodes depending on charateristics
(e.g. tube diameter, drinking water or grey water)

Now the difficulty is when a node was digitised wrongly or needs to be
corrected, all lines connecting to this node would need to be changed.

So the solution I am dreaming of is:
1) prepare a point vector layer with all nodes having unique IDs
	(e.g. Paris, Madrid, Berlin)
2) have a table where all connecting lines are listed:
     LINE_NAME, LINE_START, LINE_END
	 big tube     , Paris,           , Berlin
	 big tube2   , Madrid,        , Berlin
	 big tube2   , Madrid,        , Paris

Then, a procedure would read the connections from the table and draw
automatically these connecting lines between the nodes.
These could then slightly adjusted manually be adding more vertices or alike.
But the procedure would easy up the effort of building the network.
And in the ideal case, it would also take care of updating the lines if a
node is shifted on the map.
(Similar to a "connector" line in an Openoffice Impress drawing)

The closes tool I found so far is the 
https://plugins.qgis.org/plugins/FlowMapper/
But I think it's too complicated for my purpose.

I would really appreciate to receive any pointers or suggestions.

Thanks a lot in advance,
Kind regards,
Timmie