We’re not physicists: the things we calculate don’t usually have to be super precise. This motivates the idea of engineering estimation, where we calculate values using information, methods, and data that might be vague, imperfect, and incomplete. Sometimes we need to start with a number, we need a result quickly, to check results, or forgot instruments.

Some different methods:

  • Analogous: comparing to similar activities or designs.
  • Top-down: estimating the more significant parts of a project and forming an aggregate value.
  • Bottom-up: estimating smaller parts and adding them together.

Safe-side strategy

In MAT186 — Calculus I, we introduced a concept called the safe-side strategy. The idea is to determine upper and lower bounds, we may have to use information that is not precise. We often over- or underestimate depending on the context — we may not get the exact value but we get a value that guarantees what we’re looking for.