I'm trying to visualize a network and data transfer dataset, and would like to create a timeline that shows how long it takes for certain operations to take place (for example, uploading a dataset) while also indicating attributes of the operation (where the upload started, how big the upload was). I'd like to visualize this as a traditional timeline with time on the horizontal axis and a horizontal bar demarking start/stop times.
However I'm stuck on how to visualize additional quantitative measure (size of uploaded data) using shape or size. I'd like something like the enclosed PNG mockup, where the timeline bars have an additional glyph whose size encodes the size of the data. Thickness of the timeline bars would work too. However I've tried coloring the bars by upload size that doesn't seem to work well -- too many size gradations for people to compare effectively.
Any suggestions? Is it possible to teach Tableau to create hybrid glyphs composed of two underlying graphical objects, each of which encode different attributes in a coordinated way and are overlaid on top of each other?