Frequently Asked Question

Prioritization logic

Quality-function deployment links customer requirements to engineering characteristics and exposes positive or negative correlations. Weights should reflect customer importance, regulatory significance, competitive gap, risk, and technical difficulty. The matrix is a structured conversation, not an objective measurement of customer value.

w_i is the importance weight and r_ij is the declared relationship between need i and characteristic j.

Worked example

If three needs have weights 5, 3, and 2 and relationships 9, 3, and 1 to one engineering characteristic, the weighted priority is 5×9+3×3+2×1 = 56. Recheck the ranking when the weights or relationship scale changes.

Engineering check

For QFD House of Quality and Requirement Prioritization, maintain traceability from requirement to risk, design output, evidence, and approval. Record the configuration, acceptance criterion, test or analysis conditions, open actions, and residual risk. A method is not complete when the document is filled in; it is complete when the evidence supports the decision and affected controls are updated.

Engineering note

For QFD House of Quality and Requirement Prioritization, state the intended use, input range, dominant mechanism, units, boundary conditions, acceptance criterion, and evidence owner. Use an independent balance, limiting case, repeat measurement, or sensitivity check to challenge the result. Document the configuration and uncertainty so another engineer can reproduce the reasoning and determine whether the result remains valid after a design, material, boundary, or process change.