During a recent seminar at a UK University, a fresh-thinking students asked me whether QFD and its House of Quality could be used in reverse – i.e. starting with a finished design and working backwards to derive the Voice of Customer. Clever question. It prompted me to think about Goldenberg et al “The Voice of the Product: Templates of New Product Emergence” [Creativity and Innovation Management, September 1999: 157-164]. They draw an analogy to Darwin’s theory of natural selection, in which only products that adapt to the changing needs of the market place will survive. Competitive products are hence encoded with information about the evolution of true market needs. The information can help identify latent properties and attributes for inclusion into a new design. The question is how to retrieve, prioritise and use such information within our QFD approach.
Sources of input requirements in QFD tend to be a combination of:
- Voice of Customer (VOC).
- Voice of Competition.
- Voice of Business and Voice of Organisation, combined termed ‘organisational context’ in ISO 9001 speak.
- Voice of Product (VOP), which we could define as “information encoded in competitive products, signalling emerging and latent market needs”.
As for the other sources of input requirements, we would want to deploy our VOP through a systemised House of Quality (HoQ) chart. This is a must be in my personal view, to validate the VOP approach’s compatibility with QFD principles. I am not saying that you must use the HoQ; I am saying that you must validate in the HoQ. The HoQ charts are often unappealing in practical projects and we then tend to substitute them with our mental process. However, the principles of the HoQ workings and inter-linking remain an indispensable model for the design process – whatever approach is used. Practising the HoQ develops valuable thinking skills.
The idea of VOP is similar in thinking to TRIZ, namely about extracting shared patterns for implanting into the new design. To enable the extraction of a forward trend pattern, and thereby enhance the opportunity for innovation, the VOP should preferably evaluate related products that are in a more advanced stage of evolution than our current new design. By the term ‘related products’, we mean other products that the same customer segment already desires and uses.
The VOC is an inherently difficult exercise to get right – and when the VOC is wrong, then everything that follows in a development project will be wrong. Working the VOP for related products backwards, as indicated by the student, should in theory produce a set of principle customer requirements that are similar to the set produced from working the VOC forwards. The VOP can thereby be used to verify or resolve issues in the VOC – i.e. by validating that the same shared patterns result from both the forward tracing exercise and the backward tracing exercise, or detecting if something is missing or distorted.
The image above is a thought on deploying the VOP through a HoQ chart. It illustrates how the designers of a next generation wrist watch can implant and evaluate features from other products, which are related by desires from the same customer segment. This improves and validates the VOC, before it is carried into the conventional product design phase.
Here is another representation of the same principle, but combining the deployment of VOP into VOC into Design Requirements within a single HoQ-style chart. The VOP element is shown as a new ‘front room’ to the house. It is shown to correct omissions and importance rating discrepancies in the VOC. For example, the original VOC did not identify the customer requirements for ‘connectivity’ and ‘collect data’. The VOC also under-rated ‘comfort’ and over-rated ‘durable’ in this case.
When translating the VOP into the VOC then we must of course take care not to overwrite important customer requirements that are specific to the wrist watch design, with requirements that are specific only to the related products. We don’t necessarily want to turn the watch into a camera or music player.
The thinking behind the above example is not fully developed and there may in fact be a better place and way for introducing the VOP. An interesting study project to think about.
[first 27/02/2018, updated 23/05/2019]