The Time investment summary graph displays the percentage of items completed by type for the selected period and the cycle time corresponding to that item type. You can display this data by week or sprint, as you prefer.
According to the example presented below, we can see that 31.73% of the items worked on in the last three months were of the Story type. Furthermore, we can see that a story takes a little over four days to complete, according to the average cycle time.
The percentage corresponds to the average of the ratio of item types for the selected period, i.e. three months in the case of this example. The time below this percentage corresponds to the cycle time of each item type and is presented here for reference only.
The graph's right-hand side represents the three types of items with the most significant portion of time invested for the given period. This graph is interactive, so you can hover over it with your mouse to get more information about the other item types.
Use the Issue type time investment graph to better track the time invested per item.