What is a key feature of a 'why-why diagram'?

A key feature of a 'why-why diagram' is that it moves from left to right. This diagram is used primarily in problem-solving to explore the root causes of a given issue or challenge. The structure generally starts with a problem on the left side, and as one asks "why" in response to each identified cause, the process continues to branch out to the right. This creates a visual representation of pathways leading to the root causes, allowing teams to understand the relationships between different factors contributing to a problem.

The other options do not accurately capture the essence of a why-why diagram. The first option focuses on solutions for product design, which is more relevant to solution-oriented techniques rather than the exploratory nature of a why-why diagram. The choices regarding distribution strategies and target market demographics are distinctly different areas of concern, emphasizing marketing or logistical aspects rather than addressing problem root causes. Thus, the correct understanding of the why-why diagram centers around its left-to-right flow in analyzing and clarifying underlying issues.