Design methods

A discussed earlier, experiences of design as being 'chaotic' might well be the occasional perception among members involved in design projects, but may also be an indication of reluctance to structure the design process, or an unwillingness to employ systematic design methods. The grounds for the perception of 'chaos' might be on an individual level, but it is more likely to be due to company traditions and practice; lacking defined processes and routines for the deployment of design methods.

Cross (2000) suggests that, in a sense, any identifiable way of working, within the context of designing, can be considered as a design method. The rationale of design methods is to take advantage of previous experiences and to gain from these by aiding the design work to arrive at better solutions. It is expected that use of experience will result in more easily found solutions.

Wright (1998) notes that one of the greatest benefits to be gained from using design methods is the interaction encouraged between disparate groups within a company, and thereby the encouragement of effective communications between everyone involved in the design of products. The methods provide a 'common forum' for the exchange of ideas and information, e.g. between marketing people, designers and engineers of all

disciplines. This also applies to ergonomics integration in product design. Since the achievement from using design methods is linked to effective teamwork in itself, training

in working in teams becomes important, both for the individual and for the team as a whole, to fully attain the benefits from the methods (Wright, 1998).

Andreasen (1991) distinguishes between four areas where the theoretical basis of design methodology and models for design activities appear:

 General problem solving  Product synthesis

 Product development  Product planning

General problem solving is based on explanations of human thinking and in solving problems. Typical design methods in this area are methods to support creativity, with the aim of finding good solutions to problems, such as brainstorming and brainwriting (or 6- 3-5) methods (Wright, 1998). Another method in this area is morphology, which is concerned with the study of the structure or form of things (Wright, 1998). This method supports structured identification of alternative solutions by decomposing the overall problem into sub-problems for which a range of sub-solutions are generated and then combined according to different patterns to generate a range of alternative solutions to the overall problem (Cross, 2000). Pugh's widespread method for controlled

convergence, also commonly named Pugh's concept evaluation matrix or Pugh's selection charts, is another example of a design method within this area. The method supports the evaluation of solutions, as well as acting as a trigger for the generation of new solutions or combinations of solutions (Pugh, 1995).

Product synthesis is directed towards the design of technical systems and can be described as the sequential determination of product characteristics (Andreasen, 1991). An example is the theory of technical systems which is a systemised methodology for engineering design, based on the theoretical framework developed by Hubka in the middle of the 1970s (Hubka and Eder, 1996) where the product is seen as a, or as a part of a, transformation system where inputs are converted by a technical process into outputs. It is hard to make a clear distinction between problem solving methods and synthesis methods, as for example morphology can be seen as belonging to both areas.

Examples of design methods in the area of product development are overall product development models such as integrated product development (Andreasen and Hein, 1987) and total design (Pugh, 1995). Within this area, several design methods have been

2004). Examples of this are the so called Design for X methods such as DFM (Design for Manufacture) and DFA (Design for Assembly) for consideration of production related aspects in product development to reduce costs and increase quality (Boothroyd et al., 1994). Other examples of design methods are DFE (Design for the Environment) and Design for Remanufacturing, where the objective is to reduce the impact of products on the environment and support a sustainable development (Otto and Wood, 2001). Other design methods in this area, which can be seen as DFQ (Design for Quality) methods are FMEA (Failure Mode and Effects Analysis) to identify, define and eliminate, known or potential failure modes of a product or a system (Wright, 1998; Otto and Wood, 2001), and QFD (Quality Function Deployment also called House of Quality, see e.g. (Ullman, 2003)) which supports the linking of customer needs into product characteristics. Marsot (2005) shows how QFD can be applied in the context of integrating ergonomics in hand tool design.

Examples of design methodology related activities in the area of product planning would be methods of identifying needs or product concepts, which match the company's strategies and yield required profits (Andreasen, 1991). More about strategies, product planning and related methods in the context of design can be found in (Kotler and Rath, 1984; Baxter, 1995; Jones, 1997; Ulrich and Eppinger, 2003).

Many sources promote increased employment of design methods in industry (e.g. Andreasen, 1991; Nijssen and Lieshout, 1995; Cross, 2000). Cross (2000) argues that there is a urgent need to improve traditional ways of working in design, and that this need is due to the increasing complexity of design. One particular reason for increased complexity is due to the fact that products become more complex themselves, often consisting of several new technologies integrated more closely than before, e.g. mechatronic products. This calls for systematic design methods to support the design team in considering a range of issues, which they might have little previous experience of from earlier design projects, as well as supporting the collaboration and contribution of people with different competences. Another cause for complexity in design, and hence an argument for using systematic design methods, is related to the context in which modern product development is typically carried out, i.e. in highly competitive markets where huge investments are put into product development, and where the product development organisation is required to deliver high quality products that meet or surpass customers' expectations, carried out within tough time limits. These circumstances involve risks, mainly connected with financial consequences. One risk is that the product becomes

unsuccessful in the market by not meeting customers' expectations, e.g. due to lack of customer focus in the design process or due to deficiencies of product quality. Other risks are related to time where a delayed market introduction can cause major economic loss, e.g. due to coming second to competitors, or missing an important milestone (e.g. a fair or a season), or basically due to the fact that the product development activity causes expenses, but yields no income yet. Employing structured design methods has the

potential to reduce these risks. Nijssen and Lieshout (1995) believe that, even though the use of design methods in themselves do not guarantee success, the use of design methods can help a company's product development efforts to become more successful. However, many studies show low usage rates of design methods in industry, e.g. (Mahajan and Wind, 1992; Nijssen and Lieshout, 1995; Araujo et al., 1996; Janhager et al., 2002). Reasons for low usage rates may be unawareness or shortcomings of the methods (Nijssen and Lieshout, 1995). Cross (2000) argues that some methods appear to be over- formalised or too systematic to be useful in the rather messy and often hurried world of design, which may cause mistrust among designers of the whole concept of design methods. Another reason for the results drawn from the studies mentioned can be that design methods, or rather the purposes of the design methods, indeed are utilised in industry, but under other terms and with appropriate adaptation of the methods to suit the companies' actions hence making the methods more valuable in the companies' pragmatic interests (Frost, 1999). This makes it hard to distinguish the actual use of design methods in industry, which may cause somewhat incorrect results from surveys. Gill (1990) highlights that much research into design is undertaken by researchers who do not have real insights into or knowledge of its practice, and that may lack understanding of design as an intellectual endeavour; implying a possibility for 'noise' when communicating with practitioners. Eder (1998) considers that, even though intuition, experience, teamwork and the human qualities of designers play a large role in designing, the rationalisation, systematisation and computerisation of parts of the design process is possible and

desirable, e.g. to help with conceptualising solutions to design problems, e.g. by opening solution spaces and ensuring consideration of all factors.

The general conclusion is that there are benefits from using structured design methods in modern product development, and it is suggested, at least initially, to uphold a 'keep-it-simple, keep-control' approach towards the methods, and a tolerance of adapting the methods according to the context within which they are applied.