The two most important metrics for understanding how long work takes.
These terms are often confused. Here are precise definitions:
Lead Time: The total time from when work is requested until it's delivered.
Cycle Time: The time from when work starts until it's finished.
The relationship:
Lead Time = Cycle Time + Queue Time (waiting before work starts)
Lead time is what customers care about. Cycle time is what the team controls directly. Both matter.
Terminology Confusion
Different communities define these differently. Kanban uses the definitions above. Always clarify with your team what you mean.
Lead time is the customer's experience. They asked for something—how long until they got it?
Short lead times mean:
Measuring lead time reveals:
Most teams dramatically underestimate their lead time because they only see cycle time. "The feature took 3 days to build" ignores the 3 weeks it sat in the backlog and the week it waited for deployment.
Cycle time is the team's internal efficiency. How quickly can we complete work once we start?
Short cycle times mean:
Measuring cycle time reveals:
The variation matters as much as the average. A team with 5-day average but 2-20 day range is less predictable than one with 7-day average and 5-10 day range.
Team's cycle time ranges from 3-5 days for most items. They can confidently say 'we'll have this done by Friday' on Monday.
Team's cycle time ranges from 1-30 days. Nobody knows when anything will be done. Promises are unreliable. Planning is fiction.
Manual tracking (simple start):
Digital tools: Most Kanban tools track this automatically:
What to track:
Avoid:
Once you have cycle time data, use it for:
Forecasting: "85% of items like this complete within 8 days. I'm comfortable saying we'll have it by next Friday."
Identifying problems: "This item has been in progress for 12 days. Our 85th percentile is 8 days. Something's wrong—let's investigate."
Improvement validation: "Last quarter our median cycle time was 5 days. This quarter it's 4 days. Our process changes are working."
Right-sizing: "Large features have 3x the cycle time variance of small ones. Let's break work into smaller pieces."
The insight: Cycle time isn't just a report—it's a tool for making better decisions in the moment.
Focus on the 85th percentile, not the average. 'Most items complete in 5 days or less' is more useful than 'average is 5 days' because it accounts for variation.