Flow Metrics: Cycle Time and Lead Time in Scrum -- A Field Checklist You Can Use This Week
In Scrum, the team commits to delivering a potentially shippable product increment every Sprint. But how do you know whether your team is getting faster over time? How do you identify which work items take unexpectedly long? How do you answer a stakeholder who asks when a specific feature will be done?
Flow metrics -- particularly cycle time and lead time -- are the answer. They are simple to measure, simple to interpret, and provide more actionable information than velocity for most purposes. Here is a practical checklist for implementing flow metrics in your Scrum team.
Understanding Cycle Time and Lead Time
Cycle time is the elapsed time from when work actively begins on a work item to when it is completed. It measures the time the team is actually working on the item, not including time the item spent waiting to be started.
Lead time is the elapsed time from when a work item is requested (entered into the backlog) to when it is completed and delivered. It measures the total elapsed time from the customer's perspective, including waiting time.
The difference between lead time and cycle time is wait time: the time a work item spends in the backlog or in a queue before work begins. Reducing lead time usually requires reducing either cycle time (speed up the work) or wait time (reduce the queue).
Measuring Flow Metrics This Week
Add timestamps to your work item tracking system. To measure cycle time, you need a "started" timestamp (when work actively began) and a "completed" timestamp. Most project and issue-tracking tools capture completed dates automatically; started dates may require a manual "in progress" state transition or a date field.
Calculate cycle time for each completed item. Cycle time = completion date minus started date, in business days. Create a simple spreadsheet or use the reporting features of your tracking tool to compute this for each item completed in the last three Sprints.
Plot cycle times on a scatter chart. A cycle time scatter chart shows each completed work item as a point: the horizontal axis is the completion date, and the vertical axis is the cycle time in days. The scatter chart makes outliers immediately visible -- items that took significantly longer than typical.
Calculate your 50th and 85th percentile cycle times. The 50th percentile is the cycle time that 50 percent of your items complete within. The 85th percentile is a more conservative estimate: 85 percent of items complete within this time. These percentiles are more useful than averages for forecasting.
Use cycle time percentiles for commitment conversations. When a stakeholder asks when a work item will be done, the 85th percentile cycle time gives you a defensible answer: "Based on how similar items have moved through our system, there is an 85 percent chance this will be done within X days of starting."
XNM supports public-sector organisations in building agile delivery capability and outcome metrics. Reach out to XNM's program & project delivery advisory team to discuss flow metrics and agile delivery for your team.