WIP constraints increase flow by forcing capacity matching. Which practice supports this flow by limiting work in progress?

• A. Time boxing
• B. Increasing local WIP pools
• C. Extending iteration length
• D. Reducing visibility of WIP

Answer: (A)

WIP constraints improve flow by forcing capacity matching, so the amount of work in progress stays in line with what the system can complete in a given period. Time boxing enforces a fixed time window for work, such as an iteration, which acts as a natural cap on how much work can be pulled in. By committing to a limited scope within that window and aiming to finish within it, teams reduce overloading, minimize context switching, and create predictable throughput. This keeps work moving steadily toward completion and provides frequent feedback loops.

Increasing local WIP pools would raise the amount of work in progress, which can bottleneck flow rather than improve it. Extending iteration length changes cadence but doesn’t inherently limit WIP, so it may delay feedback and allow more work to accumulate. Reducing visibility of WIP makes constraints harder to manage and undermines the ability to optimize flow.