Lead Time vs. Cycle Time in Kanban

WHAT THIS TESTS: This question assesses your understanding of fundamental process metrics in a continuous delivery system like Kanban. The interviewer is looking for precision. They want to know if you can not only define Lead Time and Cycle Time but also explain how they are measured in a real-world system (like a Jira board) and why they are important for process improvement. For a senior role, this is a table-stakes question; a fuzzy answer is a major red flag.

A GOOD ANSWER COVERS: A strong answer clearly distinguishes the two metrics by their start and end points. First, define Lead Time as the total time from the moment a request is made (e.g., ticket created) until it is delivered to the customer (e.g., deployed to production). This represents the full customer experience. Second, define Cycle Time as the time from when work actively begins on a task until it is completed. On a Kanban board, this is measured from when a card moves into an "In Progress" column until it enters a "Done" column. Third, state that Cycle Time is a subset of Lead Time. Fourth, explain that measuring a single item's Cycle Time requires recording the timestamp when it enters the first active work column and the timestamp when it enters the final completed column. The difference is the Cycle Time.

COMMON WRONG ANSWERS: A frequent mistake is swapping the definitions or being imprecise. Saying "Lead time is how long it takes to finish something" is too vague for a senior role. You must be specific about the start and end events. Another red flag is not understanding why you'd measure both. The difference between Lead Time and Cycle Time reveals how much time work spends waiting in a queue before development starts, a critical data point for capacity planning and managing stakeholder expectations.

LIKELY FOLLOW-UPS: "Why would a team focus on reducing Cycle Time over Lead Time?" (To improve internal process efficiency and predictability, even if they can't control backlog intake). "How would you use these metrics to identify a bottleneck?" (Look for stages on the Kanban board where items pile up; the Cycle Time for that specific stage will be disproportionately high). "What is Little's Law and how does it relate?" (Work in Progress = Throughput * Cycle Time).

ONE CONCRETE EXAMPLE: A user reports a bug. The ticket is created on Monday. That's the start of Lead Time. The backlog is long, so a developer doesn't pull the ticket into "In Progress" until Thursday. That's the start of Cycle Time. The developer finishes the fix and moves it to "Done" on Friday. That's the end of Cycle Time (1 day). The fix is deployed to production the following Tuesday. That's the end of Lead Time (8 days total). The team's Cycle Time is 1 day, but the customer experienced a Lead Time of over a week.