Estimate time to build charts for a report.
Chart production time is underestimated because the average is pulled up by a minority of complex figures — a multi-panel plot with custom annotation takes several times a simple bar chart. Weighting by the complex share gives a true average, and each revision round costs roughly a third of the original effort because axis labels, colours and captions all get revisited together.
Weighted chart time
Average minutes = simple time x (1 - complex share) + simple time x multiplier x complex share
Including revisions
Total minutes = first draft minutes x (1 + 0.35 x revision rounds)
Build a reusable style template once and script the figures rather than editing each by hand. Most of the time in revision rounds is spent reapplying the same formatting decisions.
Two is typical for coursework and three or more for anything peer reviewed. Journals frequently request axis, unit and resolution changes at proof stage as well.