ASQ CSSBB Online Access

The correct answer is C. 11.58 . The CSSBB source gives the control-limit formula for an X̄-R chart as:

UCL for X̄ chart = X̄̄ + A2R̄

The same CSSBB control-chart factor table shows that for subgroup size n = 5 , the constant A2 = 0.577 (often rounded to 0.58 in summary tables). Using the values provided:

UCL = 10.66 + (0.577 × 1.59)

UCL = 10.66 + 0.91743

UCL = 11.57743

Rounded to two decimal places, the upper control limit is 11.58 . This matches option C .

This is a standard Control phase calculation in CSSBB because control charts are used to determine whether a process is stable over time. The X̄ chart monitors changes in the process mean, while the R chart monitors within-subgroup variation. Since the problem specifically asks for the X̄-chart upper control limit, only the X̄-R chart formula and the correct A2 factor are needed. Therefore, the verified answer is 11.58 .

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) .

The correct answer is D. All stakeholders . The CSSBB source states that a Six Sigma project can affect many people both inside and outside the system, and that these stakeholders may include managers of the process, people in the process, finance, suppliers, and customers. It then explicitly says that a stakeholder communication plan should be developed to reduce or remove resistance to change.

Supporting material on communication strategies also emphasizes that the communication goal is to make sure the right people have the right information at the right time , and it shows different communication methods for executive stakeholders, project team members, and other stakeholders. This makes it clear that the communication plan should not be limited to belts, finance, or senior management alone. If the project is just starting, the plan should already account for everyone affected by or influential to the project . A complete stakeholder-based plan improves alignment, reduces resistance, and ensures that communication is targeted appropriately by power, interest, and role. Therefore, the verified CSSBB answer is D. All stakeholders .

In the Control Phase, responsibility for sustaining project gains transfers to the process owner. This is a core Six Sigma principle. The Black Belt leads the project and drives improvement through DMAIC, but once implementation is complete and controls are in place, the ongoing management of the improved process belongs to the person who owns that process in daily operations. The process owner is responsible for maintaining standard work, monitoring control measures, responding to out-of-control conditions, ensuring documentation is followed, and preventing the process from reverting to prior performance. Top management and the project champion provide sponsorship, visibility, and support, but they do not manage day-to-day sustainment. CSSBB control planning emphasizes handoff, accountability, response plans, documentation , and long-term ownership, all of which point to the process owner as the key role after project closure. Sustained benefit realization depends on embedding the improvement into routine management practices. Therefore, the correct answer is The process owner, because that role carries operational responsibility for preserving the gains achieved by the Six Sigma project.