The primary thing when you take a sword in your hands is your intention to cut the enemy, whatever the means. Whenever you parry, hit, spring, strike or touch the enemy’s cutting sword, you must cut the enemy in the same movement. It is essential to attain this. If you think only of hitting, springing, striking or touching the enemy, you will not be able actually to cut him.
The McNamara fallacy, named for Robert McNamara, the US Secretary of Defense from 1961 to 1968, involves making a decision based solely on quantitative observations (or metrics) and ignoring all others. The reason given is often that these other observations cannot be proven.
The fallacy refers to McNamara's belief as to what led the United States to defeat in the Vietnam War—specifically, his quantification of success in the war (e.g., in terms of enemy body count), ignoring other variables.
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.