8 Testing of the theoretic model
From EvolutionaryProductDevelopment
8.1 Introduction
The theoretic model of the product phases is described in section 3. In section 4, research questions are formulated. In the sections 5, 6 and 7 the model is tested in two ways, first by means of a retrospective case survey (section 5), then through ranking by experts (section 6 and 7). In this section, the results of these tests are evaluated and conclusions are drawn regarding the model. The section ends with some recommendations in order to refine the model, together with suggestions for further research.
In section 4, the following research questions were formulated:
- Do the described product characteristics appear in the order that is predicted by the product phases?
- Are the product phases an appropriate means to help predict the future of a product based on its history?
- Do products always (or most of the time) follow the product phases in the predicted sequence?
- Can phasing of a product's life cycle offer designers starting points for a new product development?
8.2 Do the described product characteristics appear in the order that is predicted by the product phases?
This question can be answered on the basis of both tests. In the ranking test (study 2) forty nine statements about the product characteristics are distinguished. In seventeen cases, the experts affixed the statements so many times in the correct place that, according to the formulated criteria, this can be considered significant. In thirteen cases there is a strong indication, three times an indication and ten times a weak indication. Only on five occasions the positioning of the stickers are no better than had they been done at random, and once another position seems to be preferred. This is the case with the statement 'The product is safe'. The theory of product phases says that in the first phase products are very rarely safe, and only in the next phase (optimisation) does safety improve. However, the experts think that products are safe from the beginning, as 22% position the stickers in phase optimisation and 17% in phase performance. According to the defined criteria, this suggests a 'weak indication' and 'coincidence' respectively. The results of the retrospective case survey and discussions with some of the subjects after the tests suggests that most people think that, because of the governmental rules of today, products that are unsafe never reach the market. Safety is then supposed to mean protection against wounds and avoidance of accidents. However, in the theory of products, this is meant in a much broader sense. The ease at which people get illegal access to computer systems or the 'success' of computer viruses are also defined with this statement. The retrospective case survey strongly confirms the statement that products are sometimes not safe during the first product phase. An example includes: riding one of the first bicycles, as one had to be a true balance artist (Van der Wal, 2005). Also, some people were electrocuted by the first electric washing machines and kitchen cookers (Schol, 2005; Capota, 2005) and the first mopeds, especially the Solex, were far from safe (Van Eekelen, 2005).
8.3 Are the product phases an appropriate means to help predict the future of a product based on its history?
When this thesis was written, twenty four products had been analysed and described. Five can be found in section 5: electric shavers, mobile phones, bicycles, shampoo packaging and holidays. The remaining nineteen were described by students as a part of the master's course on 'Evolutionary Product Development' at the University of Twente. Based on these cases, it can be concluded that the theory is fit to describe the history of a product. However, some cases deviated from the theory, but these were generally attributed to the influence of external factors, such as World War I or II, the growth of a competing product, etcetera.
With regard to predicting future developments: students are very capable of developing and styling new products with the aid of the theory. However, the time frame between the students designing these products and the finishing of this thesis is too short in order to judge if their designs will be seen through to fruition.
8.4 Do products always (or most of the time) follow the product phases in the predicted sequence?
The answer to this question can only be based on the retrospective case survey. In the 'ranking by experts' experiment, no examples of products were given. Therefore, it can be concluded that the products that were analysed, do indeed pass through the product phases in the predicted sequence. However, a few remarks have to be made with this statement. Firstly, it has been proved that it is difficult to mark the transition between the phases, and in most cases the transition is slow and over a long period of time. Secondly, it turns out that the product characteristics from previous product phases can return in the actual phase. Finally, it must be noted that the endeavour for technical innovations remains important during all of the product phases, but that the 'real' innovations mostly occur during the first product phases. In the latter phases they appear less frequently and have long time intervals.
8.5 Can a phasing of the life cycle of a product based on the product phases offer designers starting points for new product development?
This question only came into view with the students that worked with the model (see section 8.3). As stated in section 8.3, the students were able to work with the model and come with new product concepts. The students acknowledged this when they were asked, but it should be noted here that they had been instructed to develop a new product based on the theory. Finally, it would be interesting to ask the students many years from now (long after they had finished their studies) whether they still use the model and what they thought of the results.
