The Lead Time Histogram is another visual reporting mechanism used extensively in Kanban. A histogram is a vertical bar chart that reflects the distribution of a particular set of data:
As suggested by its name, the Lead Time Histograms shows the distribution of work card lead times for all items completed within the date range you select. So if your team completed 10 work cards in the span of a week, each card would have been "in progress" within your system for different amounts of time. One work card may have moved through your team in less than a day, another may have taken 7 days. Lead time value is calculated on the date the card is "done," which means it could have been in your system long before the "start date" selected for your report. The histogram plots the distribution of these times and allows us to easily discern where the bulk of a team's lead times for completed work lies.
Having an improved understanding of a teams distribution pattern directly translates to better planning and forecasting capabilities.
NOTE: When generating this report, it's very important to select your appropriate start and end steps to get the specific data (and understandings) for which you're looking.
Start and End Step
These options specify the step in the workflow that we should begin counting time, through when the work has been completed for this report.
When viewing this report, it’s very important to make sure to select the start and end steps that you wish to view the data across. For example, if you have a “done” or "deployed" state, you likely want to select it as your end-step. If you don’t, the time spent in the column where work waits to be archived will be utilized.
Start step and end step options can be very useful for slicing the data to get more specific information. In the example below, the start step was set for doing, and the end step for reviewing. In this sample project, those steps come right after one another (Todo, Doing, Reviewing, Done). This results in a report that shows us how long work stayed in the Doing step. The report tells me that most work is handled in the doing state in just 1-3 days, but occasionally it takes significantly longer (5 or 10 days).
The interval option allows you to control the grouping on the horizontal axis. One or three days will cause each bar to represent either one or 3 days respectively. Selecting the powers of 2 option will make the first bar represent one day, and then each subsequent bar represent 2, 4, 8… days.