Design practice: which methodology explicitly considers a part’s dimensions and tolerances and how that part functions and assembles relative to mating components in the product?

Introduction / Context:
Robust designs account for variation. Geometric dimensioning and tolerancing (GD&T) offers a symbolic, standardized language to control form, orientation, location, and runout so parts assemble and function correctly despite manufacturing variation.

Given Data / Assumptions:

• A product involves mating parts.
• Both size and geometry must be controlled.
• Functional requirements drive tolerancing decisions.

Concept / Approach:
GD&T ties permissible geometric variation to functional datums, enabling clear fit/function definitions, better interchangeability, and often larger, cost-saving tolerances compared to simple plus/minus size limits alone.

Step-by-Step Solution:

Verification / Alternative check:
Tolerance stack-ups that include geometric controls typically show improved assembly yields and clearer acceptance criteria compared to size-only schemes.

Why Other Options Are Wrong:

• Applying allowances: addresses intentional clearances/interference but not full geometry.
• Creating datum references: a component of GD&T, not the whole methodology.
• Angular dimensioning tolerances: a subset of tolerancing, not a comprehensive system.

Common Pitfalls:
Using GD&T symbols without establishing a sensible datum scheme; always start from function and assembly path.

Final Answer:
Geometric dimensioning and tolerancing