Pert diagrams are usually drawn in such a way that connections "flow" from left to right. Nodes are usually represented as circles.
Speaking in terms of graph properties, Pert diagrams are directed graphs and usually have exactly one source node and one sink node.
We suggest to represent Pert diagrams with upward drawings, i.e., drawings in which the connections between symbols "flow" in a common direction (from bottom to top). A 90 degrees rotation will complete the job. A further suggestion is to exploit the GDT capabilities for customizing a drawing for constraining the source and sink nodes to stay on the "external face".
The following figure shows an example of a Pert diagram constructed with GDT.
GAPI tutorial on upward drawings and BLAG tutorial on upward drawings provide a comprehensive guide on how to use GDT to construct these widely used drawings.
Another possibility is to represent Pert diagrams with visibility drawings. GAPI tutorial on visibility drawings and BLAG tutorial on visibility drawings provide a comprehensive guide on how to use GDT to construct these widely used drawings.
An example of system that uses GDT for Pert diagrams visualization is BusinessFlow.