For a specific Sprint Backlog item that has been started, what is the best chart (analytic) to determine when it will be finished?
Answer: A
A. Work Item Aging Chart: Correct. Per PSK I content, the Work Item Aging Chart plots each active in-progress work item against the number of days it has been in the workflow, with overlaid historical cycle time percentiles (typically 50th, 85th, 95th) for the team's established process. For the specific started Sprint Backlog item in the question, you can cross-reference its current age against these percentiles to generate a probabilistic forecast of when it will complete, which directly addresses the scenario requirement.
B. Throughput Run Chart: Incorrect. Throughput is an aggregate metric that measures the total number of work items completed per fixed time period (e.g., per day, per Sprint). A Throughput Run Chart tracks this aggregate count over time to forecast how many total items the team can complete in a future period, but it provides no data on individual in-progress items, so it cannot be used to predict when a specific started item will finish.
C. Control chart: Incorrect. The cycle time Control Chart referenced in PSK I tracks historical cycle times of already completed work items to identify process stability, common cause variation, and special cause variation. It only uses data from finished items and does not track the current age of in-progress individual items, so it cannot generate a completion forecast for the specific started Sprint Backlog item in the question.
D. Cumulative Flow diagram (CFD): Incorrect. The CFD is an aggregate system-level chart that shows the count of items in each workflow state over time. It can be used to calculate average system cycle time, WIP levels, and throughput for the entire workflow, but it does not track individual work items. There is no way to isolate data for a single started Sprint Backlog item on a standard CFD, so it cannot answer the question of when that specific item will finish. Key Concepts:
1. Work Item Age: This is a core Kanban flow metric defined as the elapsed time from when a work item enters the "in progress" segment of the workflow to the current point in time. Per PSK I content, it is the only flow metric designed to forecast completion for individual active work items.
2. Probabilistic Forecasting with Cycle Time Percentiles: PSK I emphasizes using historical cycle time percentiles rather than average cycle times for reliable, realistic forecasts. Work Item Aging Charts overlay these percentiles to give teams clear, data-backed estimates of the likelihood an in-progress item will complete within a given timeframe.
3. Aggregate vs Individual Flow Metrics: PSK I distinguishes between system-level aggregate metrics (throughput, average cycle time from CFD, control chart cycle time) that forecast overall team performance, and individual item metrics (work item age) that forecast outcomes for single work items, ensuring teams select the right metric for the specific question they are answering. References:
Kanban Guide for Scrum Teams, Professional Scrum with Kanban (PSK) Learning Resources, https://www.scrum.org/professional-scrum-kanban-psk