Once you see that an answer is not serving its question properly anymore, it should be tossed away. It's just their natural life cycle.
They usually kick and scream, raising one hell of a ruckus when we ask them to leave. Especially when they have been with us for a long time.
You see, too many actions have been based on those answers. Too much work and energy invested on them. They feel so important, so full of themselves. They will answer to no one. Not even to their initial question!
The hardest thing about customer interviews is knowing where to dig. An effective interview is more like a friendly interrogation. We don’t want to learn what customers think about the product, or what they like or dislike — we want to know what happened and how they chose... To get those answers we can’t just ask surface questions, we have to keep digging back behind the answers to find out what really happened.
The traditional process of delivering design, vs. delivering design just in time.
Designers are often working at least one sprint ahead of engineers. While one sprint might not seem like much of a lag, a typical product team learns a lot after the design hand-off. ...Instead of working ahead, we should finish designing as close to the end of a sprint as possible: just-in-time design.
Get embedded in the team. Designers should use sprint planning, grooming, standup, and retro as opportunities to provide design to — and receive feedback from — the rest of the team. Designs can take the form of written or verbal descriptions, not just wireframes and high-fidelity mockups.
Only design what’s needed. Use constant communication between engineering and product partners to understand what your collaborators will need next. Then, plan on delivering only what is needed, and nothing more. Use the agile process — grooming, planning, and retro — to find any shortfalls or excesses.
Avoid creating a backlog of designs. Designs don’t age well. In the time between finishing design and shipping code, it’s likely that you’ll learn something new that changes your understanding. If you’re producing more design than can be implemented, focus more on the quality of each design.