Pjm Peter Sonnemans

Quality and Reliability Problems from a Consumer's Perspective: an Increasing Problem Overlooked by Businesses?

Currently, many businesses in the consumer electronics industry are facing an increasing number of consumer complaints, despite the application of quality tools that proved to be very powerful in the past. We assessed over 20 new product development projects, to understand the reasons behind the rising number of consumer complaints. We found that businesses are developing more innovative products that are brought to the market faster, with inherently higher uncertainties on the consumer expectations of these products. Current analyses of consumer complaints solely focus on checking if the product is functioning according to the technical specification, and these analyses show a rising number of consumer complaints where no failure could be established. When looking at product quality and reliability from a consumers perspective, we found that consumers complain not only about technical product failures but also when the product does not satisfy their expectations. In this paper we will take the perspective of the consumer to analyse dissatisfaction with new products from various available sources, which were not set-up for quality and reliability purposes. We will show that analysing information from these sources gives better information, especially on the non-technical failures compared with the traditional quality and reliability sources. Copyright

Managing product reliability in business processes 'under pressure'

Product reliability is often seen as a product attribute. Models with different degree of sophistication analyze and predict the reliability of a product as a function of the internal structure (such as components and their relation). The practical relevance of these models, in relation with the (business) processes in which the related products are actually used, is not often addressed. Different types of reliability issues, however, can be relevant for products in different industrial contexts. This paper will present a classification model to describe different business processes, based on the degree of product innovation. It will also propose a taxonomy that can be used to classify different types of reliability problems. As this paper will demonstrate, only certain combinations of reliability problems are relevant for certain business processes. It will also show that, given certain technology trends, some combinations will become more relevant in the future. The final part of this paper will demonstrate that especially for these combinations many of the existing reliability analysis and prediction methods can be considered inadequate.

Numerical and Experimental Study of Lean M-and V-Shaped Flames

Abstract Numerical modeling results of M-and V-shaped methane/air flames with an equivalence ratio of 0.7 are presented and compared with experimental results in this paper. The numerical model uses a one-step chemistry model and a vorticity-streamfunction formulation for the flow field. The experimental results used to validate the model consist of flame shapes, stand-off distances, velocity profiles measured with Laser Doppler Velocimetry and critical transition and blowoff gradients. The flame shape and the stand-off distance of the M-shaped flame are reproduced well by the model. The values of the vertical velocity are. however, lower than the experimental values. The lower vertical velocities computed with the model are due to relatively small differences between the computed and the experimental flame shape. The shape of the V-shaped flame is also reproduced reasonably well by the model. The stand-off distance predicted by the model differs 0.8 mm from the experimental value. The vertical velocities...

GLOBAL CONDUCTIVITY OF REPETITIVE STRUCTURES

A general applicable method is presented to determine conductivity properties of repetitive heterogeneous structures from the material properties of their constituents. The method is an extension of an analysis given by Rayleigh and is demonstrated to determine the global conductivity of a regularly perforated brass plate used as a flat-flame holder. The method is also applicable to other analogous transport properties in a wide variety of geometrical configurations.