Which of the following tools is designed to reduce cycle time?

The correct answer is A. Single-minute exchange of dies (SMED) . In the CSSBB Improve-phase material, SMED is presented under Lean methods / cycle time reduction . The source explains that setup reduction, also called SMED, is one of the most important Lean tools and is specifically intended to take long setup changes and reduce them to minutes . It also states that reducing setup times expands production capacity, reduces inventories, increases flexibility, and improves responsiveness.

Because setup time is a major contributor to lead time and cycle time, reducing it directly supports faster flow and shorter overall process time. The other options do not fit this purpose. Double sampling is a sampling-plan concept, WIP holding areas generally increase delay rather than reduce cycle time, and SPC is used to monitor variation and stability rather than directly shorten cycle time. In Lean Six Sigma, SMED is a classic speed and flow improvement tool. Therefore, the verified CSSBB-based answer is A. Single-minute exchange of dies (SMED) .