The correct answer is D, Factor B low, because the main-effects plot indicates that the response is lowest at the low setting of factor B. In a main-effects plot, the average response is plotted at each level of each factor, and the team compares the height of those plotted means to determine which settings increase or decrease the outcome. The factor level associated with the lowest plotted point gives the lowest average response. In Six Sigma Analyze and Improve work, this is a fundamental DOE interpretation skill. Black Belts use main-effects plots to identify which factor settings move the response in the desired direction and to determine promising operating conditions for further study or optimization. The steeper the line, the stronger the main effect of that factor on the response. This question focuses only on identifying the lowest response setting, and from the plot that point occurs at factor B low. Therefore, the correct answer is D, because the low level of factor B corresponds to the minimum response among the settings shown.

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Company XYZ is an external customer to Company ABC because it is a separate organization receiving ABC’s output. In Six Sigma terminology, an internal customer exists within the same organization and depends on the output of an upstream process, department, or function. An external customer exists outside the organization and receives the product, service, component, or information produced by the organization. In this case, Company XYZ purchases components from Company ABC and uses them in its own product, making XYZ an organizational customer outside ABC’s internal structure. It is not the final customer because the general public ultimately buys the finished product from XYZ. It is also not necessarily a distributor, since the scenario describes incorporation into another product rather than simple resale. Understanding customer type is important in Black Belt work because customer requirements, quality expectations, and CTQs may differ between internal and external customers. Supplier-customer relationships across organizations must be managed carefully to ensure consistency, reliability, and fit-for-use performance. Therefore, the correct answer is A, External, because Company XYZ is outside Company ABC and directly receives its components.

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In line balancing, takt time represents the pace required to meet customer demand. To find the work content of a station as a percentage of takt time, divide the station’s cycle time by the takt time and multiply by 100. From the chart, takt time is 30 units and Station 3 has a cycle time of 20 units. Therefore, the percentage is 20 ÷ 30 × 100 = 66.67%, which rounds to 67%.

This is an Improve Phase concept because line balancing is used to redesign work allocation so that stations are better aligned with demand and flow. A station operating at 67% of takt time has unused capacity relative to customer demand, meaning it is not a bottleneck. In contrast, stations above takt time would constrain throughput and require balancing action. Black Belts use this kind of analysis to identify imbalance, redistribute work, reduce waiting, and improve flow efficiency. The chart shows that Station 3 is below takt and therefore has capacity available. Therefore, the correct answer is C, 67%, because Station 3’s work content is two-thirds of the takt requirement.

The correct answer is A. Flowchart . In Six Sigma and process analysis, a PFMEA is built around understanding the process steps , potential failure modes at each step, their effects, and their causes. The supporting project-documentation material identifies both updated process maps and Failure Modes and Effects Analysis (FMEA) as part of project documentation. In addition, process analysis and documentation are explicitly carried out using process mapping and flow charting .

This means a flowchart is the most appropriate companion document for a PFMEA because it shows the actual sequence of process steps where failures may occur. It helps the team ensure that no major step is overlooked and that each failure mode is tied to the correct activity in the process. A stem-and-leaf plot is a data-display tool, not a process-documentation element for PFMEA. QFD is used for translating customer requirements into design characteristics, and Hoshin planning is a strategic planning tool. Neither serves as the direct process-step reference needed for PFMEA documentation. Therefore, the best verified answer is A. Flowchart .

The correct answer is C. 81 . In DOE, the total number of runs starts with the number of treatment combinations in the design, then is multiplied by the number of replicates. For a 3-level design with 4 factors , a full factorial design would require 3⁴ = 81 treatment combinations. Since this question specifies a 1/3 fractional factorial , the base design is reduced to 81 ÷ 3 = 27 treatment combinations. With 3 replicates , the total required number of runs becomes 27 × 3 = 81 .

This is consistent with CSSBB DOE principles, where the number of runs depends on the number of factors, levels, fraction, and replicates. The CSSBB materials also emphasize that replicates are used to reduce experimental error and increase the power of the experiment, and that the design choice must balance information needs with budget and practicality. The source further discusses screening and multi-level designs, noting that 3-level designs are used when non-linear effects are expected. Therefore, after applying both the fractional reduction and the 3 replicates, the required total is 81 runs .