Which rule is sometimes cited as a numerically framed counterpart to underestimation in project planning?

Which rule is sometimes cited as a numerically framed counterpart to underestimation in project planning?

• A. Hofstadter's Law
• B. 90-90 Rule
• C. Pareto Principle
• D. Sidewalk origin

Answer: (B)

In project planning, a common trap is thinking tasks will take less time than they do. A numerical way to express a counterpoint to that tendency is the 90-90 Rule: the first 90% of the project often takes about 90% of the schedule, and the last 10% of the work tends to demand roughly another 90% of the time. This framing shows why estimates slip in a very concrete, time-focused way—the finish usually requires more time than we expect, even after we’ve accounted for some delay earlier. It helps teams plan buffers and manage expectations by emphasizing how finishing touches, integration, and surprises can disproportionately extend the timeline. Hofstadter's Law covers the idea that things always take longer than we think, even when we try to account for it, but it’s not a specific numeric rule about how time divides across a project. The Pareto Principle is about a small portion of effort producing most results, not about the timing distribution of project completion. And “Sidewalk origin” isn’t a recognized rule in this context.

In project planning, a common trap is thinking tasks will take less time than they do. A numerical way to express a counterpoint to that tendency is the 90-90 Rule: the first 90% of the project often takes about 90% of the schedule, and the last 10% of the work tends to demand roughly another 90% of the time. This framing shows why estimates slip in a very concrete, time-focused way—the finish usually requires more time than we expect, even after we’ve accounted for some delay earlier. It helps teams plan buffers and manage expectations by emphasizing how finishing touches, integration, and surprises can disproportionately extend the timeline.

Hofstadter's Law covers the idea that things always take longer than we think, even when we try to account for it, but it’s not a specific numeric rule about how time divides across a project. The Pareto Principle is about a small portion of effort producing most results, not about the timing distribution of project completion. And “Sidewalk origin” isn’t a recognized rule in this context.