Consistency check of a house of quality chart

Quality function deployment (QFD) is a cross‐functional planning tool which ensures that the voice of the customer is systematically deployed throughout the product planning and design stages. One of the common mistakes in QFD is to perform analysis using an inconsistent house of quality (HOQ) chart. An inconsistent HOQ chart is one in which the information from the roof matrix is inconsistent with that from the relationship matrix. This paper develops a systematic procedure to check the consistency of information contained in an HOQ chart. The proposed consistency check can be performed prior to QFD’s main analysis to ensure the validity of the final results. A procedure for identifying the source of the inconsistency, if the HOQ chart should fail the consistency test, is also developed. The proposed procedures are illustrated through examples.