Visual homogeneity is a key dimension of percieved quality. However, the choice of technologies of plastic parts is constrained by the cost which often involves different technologies for contiguous parts of the interior (dash board, door panel, ...). The result of these choices can be read by the consumers as 2 different aspects despite the intention of an identical visual aspect.
The questions under study were :
- Are perceived gaps (brightness, color, grain) between 2 contiguous parts identical for consumers, panelists and experts ?
- Are thresholds of acceptance of these perceived differences identical for customers, panelists and experts ?
- What is the impact of these differences on the perception of homogeneity ?
The study was conducted on 6 areas of 8 cars :
- 120 consumers assessed homogeneity, quality, visual acceptability, perception of difference, acceptability of the perceived difference.
- 12 panelists evaluated the intensity of 7 descriptors for each part of the 6 areas.
- 6 experts responded to each part of each area to the question "would you validate or ask an iteration to the supplier ? "if so on which dimension ?
Preference Mapping internal and external treatment, regression PLS and regression trees have been conducted on each area. Expert data were projected in illustration.
Consistency between assessments of consumers, panelists, experts was looked at by area.
A predictive tool of the homogeneity calculated from the sensory profile of parts has been developed on the basis of this study.