Understanding the diagram

Owned by Marc-André Thibodeau
Last updated: Sept 23, 2013
3 min read

 

 

Diagram elements

The diagram is made of nodes and directed edges between these nodes. This section gives details about the elements found in the diagram.

Nodes

The nodes in a diagram represent any type of JIRA issues (epics, stories, tasks, bugs, etc.). Nodes are drawn as blue rectangles by default. Their color changes depending on user action's.

A node displays basic information about the issue, namely

  • the issue key, 
  • the first 16 characters of the summary,
  • the remaining time (or original estimate if remaining time is not explicitly specified, or empty if neither remaining time or original estimates are specified),
  • an icon indicating the type of the issue,
  • an icon indicating the priority of the issue

Hovering a node with the mouse pointer brings up a tooltip giving more detailed information about the issue.


A node tooltip

The tooltip displays the following information:

  • the issue key,
  • the summary
  • the status
  • the priority
  • the original estimate
  • the time remaining
  • the due date
  • the assignee

Nodes positioning

The nodes in the diagram are positioned using a force-directed graph layout algorithm. This algorithm uses physics rules to place nodes in a way that tries to minimize node overlapping and edge crossing.

Of course, the selected issues might not all be connected. Furthermore, some of these issues might be connected to no other of the displayed issues. The latter are called orphans. So in order to make the diagram clearer, the force-directed layout used in Pathfinder is adapted to make nodes attracted to different places on the canvas. Nodes are placed using the following rules:

  • Each group of connected nodes is displayed horizontally, with edges directed from left to right.
  • Groups of connected nodes are displayed one under the other
  • Orphans are displayed at the bottom of the graph

The automated graph layout complexity

Graph layout is notably a complex problem and no layout algorithm will yield perfect results in every case. The readability of the rendered graph will depend on many factors, such as the number of nodes displayed, the number of nodes in a specific group of nodes, the presence of cycles in connected groups, etc. Pathfinder offers you many options to help you view your issues better, such as hiding orphans, limiting the nodes displayed by specifying the what issues to discover, moving nodes around, zooming and panning, etc.

Edges

Edges connect two nodes together and represent the links between JIRA issues. The edges of the diagram are directed, meaning they go from a source node to a target node. For example, if the context of a link of type 'Blocks', an edge from node ABC-1 to node ABC-3 would mean that Issue "ABC-1 blocks issue ABC-3". The type of links being displayed in the diagram is indicated by the Link type selected in the parameters panel on the right.