43 In conclusion, it is claimed that the primary causes which make the generic product development processes adaption linear and limit their application among industrial practitioners include:
• Development project management process strives to freeze the technical solution prior to actual development which leads to manage product architecture through the creation of physical single discipline blocks or modules.
• Professional disciplines and their development processes that aim to manage complexity by separating functional structures into different disciplines and defining interfaces between them. This directs design activities to partial optimization within the borderlines of each discipline.
• Development process approach aims to associate one-directional logic of requirements-specification-properties-characteristics whereby the purposeful behaviour is achieved later when physical integration of part structure is assembled.
This is in contradiction to the principal approaches to complex systems which consist of large numbers of parts that have many interactions, and in such systems the whole is more than the sum of parts (Simon 1996).
The implementation of several disciplines within one product concept is challenging and is followed by principal concerns on traditional product development processes.
The realization of functions is no longer only the result of mechanisms, the definitions and modelling of function structure, product architecture and organ structure as well as part structure has to be reconsidered.
In consequence, it is obvious that the creation of innovative solutions may need to be initiated in a different way.
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Many enterprises have dedicated research and development (R&D) sections with varying scopes depending on their resources and competence. However, as the new product development includes numerous financial, technical and scheduling risks, R&D activities on the enterprise level explore new technologies regardless of at what stage any particular product development project is. Consequently, new technologies and solutions are implemented into the subsystems of existing products according to the incremental development drivers. However, new technology introduction in existing products is only one driver for incremental development which leads that the development task setting, purpose and applicable methodologies differ from new product development.
Idea generation and innovativeness are challenged to respond to the quest for enterprise success with the development of existing products or concepts.
Incremental development has received mild interest within the engineering literature, regardless of its need in industrial application. Hubka (1988) identified two major aspects for product development; the development of a particular technical system from idea to realization and developments over a longer time period as a succession of technological developments. The first aspect relates to new product development and the latter refers to incremental development. The technology development, evolution and the increase of the main useful functions and systems transitions were also presented by Altschuller (1996) as one element of the TRIZ- methodology for solving contradictions within problems or existing concepts.
Different product development types have been identified that have the distinction based on the influence of a product portfolio; new product platforms, derivatives from existing product platforms, incremental improvements and fundamentally new products (Ulrich &
Eppinger 2003). In addition, Cooper (1993) has acknowledged types of repositioning and cost reduction. Furthermore, generic product development processes (Ulrich & Eppinger 2003, Pahl & Beitz 1996) focus on new product development, thus acknowledging the incremental aspect, but also suggesting the utilization of similar process flows and methods.
Multilevel hierarchical matrices were introduced by Eekels (1990) as a continuation of the basic design cycle, in which goal setting is followed with a stage analysis, a set of requirements, synthesis, simulation, evaluation, selection and implementation. When design problems exert pressure on many dimensions, they are difficult to address. Based on this approach, different viewpoints on design evaluation and environment were built into three-dimensional matrices – cubes – to map out the design domain. The two cubes, design and evaluation include the dimensions: basic design cycle – innovation career – aspect and design problem – design career – design object. As the primary purpose of the use of matrices is to structure evaluation and decisions over a design task, the multiple dimensions introduce the nature of different interactions within a design problem.
Pugh (1996) identified the conflict that exists with reference to the spectrum of design activities and in relation to the variety of the designer’s boundaries within the conceptual envelope regarding innovatory or conventional design tasks [Figure 4.10].
45 Figure 4.10 Variety of design tasks, the spectrum of design activities of innovatory for
“white board approach” and conventional for re-engineering or re-use of proven solutions. Adopted from Pugh (1996).
The distinction between conceptual and embodiment design was raised by Pugh (1996) in reference to dynamic and static product concepts. The finding from industry was that mostly the tasks of embodiment design were already made during the conceptual stage with static concepts, and were more of a subset of conceptual design. For the management of development work, Pugh introduced the enhanced QFD (EQFD) concept selection method [Figure 4.11].
Figure 4.11 The basic process of EQFD, dividing the concept selection into total system architecture (TSA), subsystem (SS) and component (PP) levels, enabling the evaluation of static/dynamic concept on each level. Adopted from Pugh (1996).
The process model is an application of quality function deployment and decision dispersion into three levels of the system. The static and dynamic concept evaluation is also considered on each level and further development follows the previous concept and matrix. The total system expectations are built on the requirements received from the collection of the opinions of the customer. The sub-systems expectations are further led from the total system decisions into the matrix with total system expectations. The matrices are continued to the lowest part-piece level by decisions from the upper level and requirements from the current level (Pugh 1996).
Incremental development has the advantage of having a concept to build on and compare.
However, a distinction between product improvements and incremental development needs
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to be made. Product improvements are the type of modifications which include the change of material, part content or manufacturing technology for lower costs or better quality, the improvement of some property or performance characteristic or other activity, which maintains the product concept and operating principle. In contrast, incremental development involves a partial conceptual modification, where the operational principle of the product or some subsystem is changed.
The principal difference between incremental development and new product development is that the new product development process progresses from idea to solution and product, while the incremental development begins from a product or concept to idea and again to solution.
As said earlier, enterprises tend to bring developments through subsystems to existing products and therefore the design process has some analogy with types of reverse or re- engineering design.
Otto & Wood (1998) have presented an evolved process of reverse engineering and redesign methodology. The process consists of three phases; reverse engineering, modelling & analysis and redesign. The first phase includes investigation, predictions and a hypothesis, which assumes the product to be a black box that is experienced with respect to customer needs. During the second phase, the development of design models takes place, with which the analysis and experimentation are executed. The third phase initiates the product redesign based on the results of the earlier phases, either as parametric redesign, adaptive redesign or original redesign [Figure 4.12].
Figure 4.12 Reverse engineering and redesign methodology leading to parametric, adaptive or original redesign. Adopted from Otto & Wood (1998).
The methodology involves the reconsideration of functions and structure, the evaluation of properties utilizing quality function deployment (QFD) and the application of value engineering (VE). As any new solutions for functions are explored, the methodology proposes the use of brainstorming, discursive bias, morphological matrix and theory of inventive problem solving (TRIZ). As all previous tools are familiar from new product development, an additional view of functional modelling was introduced, which is the flow of physical phenomenon intrinsic to product operation. The context of flow in reverse engineering enables a reverse view on the design process, which moves from abstract to real, but here moves in the opposite direction.
In case of incremental development, the product and function structures already exist and the design process and documentation is strictly divided into technological disciplines:
mechanical, electrical and control systems. This separation is a natural result of discipline based product specifications and development teams. However, function structures may be directed towards the separation of disciplines already during the conceptualization stage.
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