Developing an Industrial Product, page 3:

Synthesis in Product Development

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Analysis - syntesis - evaluationThe design phase is based on the product concept which normally gives a list of desirable product attributes. It is discussed on another page.

The procedures of design will depend on whether customers and users of the product can participate in the work, or shall it be done entirely by professional designers. A professional designer is accustomed to work on an abstract level, can discuss the various properties of the product, and he can make use of all the published theories of design. As a contrast, a typical user seldom thinks of isolated properties of a product; instead he or she prefers to regard the product as a whole, holistically. Instead of a theory of design the user would like to discuss and evaluate exemplars, i.e. other similar products, or realistic prototypes.

Professional Design

In the following discussion "professional design" means that the designer, or a team of them, prepare their proposals without daily contact to the customers. The communication between the parties is secured by regular meetings where the state of the project and the latest draft proposals are discussed. The designers prepare renewed outlines until the customers and other involved parties become satisfied with them.

A lot of research has been done on the work methods of designers. One approach of study has been an empirical one: scientists have investigated the factual work methods of famous - or just average - designers. On the other hand, researchers have tried to discover the most efficient methods for artistic or engineering design; however, a general formula for either has not been found.

It seems that there are several alternative styles that are possible in the design of products. Their principles as well as processes are quite different, but competent designers are often capable of choosing between several of them, depending on circumstances. In the following, four well known and common approaches of design are explained.

1. Logical reasoning as a design method aims at finding just one, final and optimal solution on the basis of given targets and factual circumstances. This technique is possible only if the designer knows exactly all the targets and restrictions as well as their mutual relations, and if these are accepted by all parties involved (including the end users of the product).

The design process using logical deduction is sometimes called "rational planning process" and it consists ideally of the following operations:

  1. Description of the starting situation
  2. Description of the target situation
  3. The difference between 1 and 2 gives the objectives for the project
  4. Conceiving alternatives to reach the objective
  5. Predicting the consequences of each alternative
  6. Assessing the consequences
  7. Selecting the best alternative.

The initial three phases of the process are often readily feasible with the usual methods of descriptive research. The phases 4 and 5 are conventional routines for a proficient designer. In those fields of industrial production where this type of task is usual, it is even possible that researchers develop standard patterns of deduction or calculation which the designers can use in most tasks for finding the optimal (or at least adequate) solutions. Such is the case in many fields of engineering where the prevalent theory of design includes algorithms and formulas of deduction for the design of, for example, traffic network or bridge construction. They can often be carried out by a computer, which can accelerate the design a great deal, especially when computer aided design (CAD) is used.

The weakest point in the model are phases 6 and 7 where the designer has to consider simultaneously a multitude of requirements from different parties: the evolving needs of various groups of people, the environment, production technology and conjunctures. Their common evaluation is obviously possible only if the consequences of alternatives are exactly known and there are not too many personal differences in their evaluation. Such a lucky condition does not always exist in the design of products for personal use.

Many researchers of design methods have proposed dealing with complicated problems by applying the method of Descartes, given as the rules #2 and #3 in the Discourse on the Method (1637): by dividing the problem into "manageable parts" and solving separately each of these, beginning with the simplest issues and ascending to the more complex. Thus, Christopher Alexander in the book Notes on the synthesis of form (1964, p.94) illustrates the method with the help of two logical trees (below). The one on the left presents the process of analysis: cleaving the requirements to the future product into their constituents. The second tree symbolizes synthesis where the solved problems, presented as diagrams, are added together. "At the apex is the last diagram, which captures the full implications of the whole problem, and is therefore the complete diagram for the form required" says Alexander. However, practicing architects and designers soon found that it is seldom possible to cleave design problems in so independent parts that these could be solved in isolation and again combined successfully. In other words, it seems that Alexander's method may work sometimes, but it is no Philosopher's stone for all the problems of design.

Alexander's design method

2. Iterative methods rely on the process of gradual improvement. The designer makes first a tentative draft of the project, and then corrects its weaker aspects or components in piecemeal fashion until a "satisfying" arrangement is found. This method is also called "incremental" planning.

An early example of iterative design is the ancestral method of artesans where tradition played a cardinal role; it provided the standard pattern from which the new product could be developed by making just a number of small improvements. However, today so many changes to the traditional model are usually needed that the usefulness of tradition has diminished. It can sometimes be used as one of the starting points of the professional designer, to give inspiration and preliminary solutions to base the new design on.

"Seldom the idea for a building appears as if from nowhere. There is always some kind of a link between the preceding work and the new one. ... Usually a previous project has been the preliminary stage of a later one. Something in it becomes the central theme for a new work" (Pietilä 1985, p. 26.)

As a starting point for the iterative design method you will need a tentative proposal, the quality of which is not critical. You can create it with any method, or you can start at an earlier version of the product that is to be designed.

Once a preliminary design is at hand, you repeat the following procedure until an optimum is found:

  1. specifying the inadequacy of the tentative proposal
  2. creating an improved solution
  3. evaluation: is the new alternative better than the preceding ones?

IterationThe iterative method has some inherent weaknesses. While iteration usually leads to a better solution, it may nevertheless fail to find the best alternative of all.
An example of this is illustrated in the figure on the left: if the iteration process is started at option A, it will eventually lead to alternative C. This is, however, only a partial optimum: while it is certainly better than the neighbours, it is far from the absolute optimum S, which is radically different and could never have been found by iteration only. Obviously, if you consider only alternatives that do not differ much from the old one you never invent something radically new.

Another weakness of the iteration method is that it cannot handle more than one feature of the object at a time. If you have several alternatives which diverge from each other in more than one respect, you will find it impossible to compare and rank order them with the iterative method. Iteration works well if your alternatives differ in just one respect or attribute of the object, otherwise it may lead in the wrong direction.

The iterative method is at its best in the later phases of design, when you have created at least one potential solution (using other methods) and you feel that it is not yet optimal.

3. Trial and error. When you have the possibility of choosing among alternatives which have a large variation, and the number of the alternatives grows, the probability increases that there is an acceptable alternative among them. This holds true also when the average acceptability of the alternatives is quite low, and even when they have been generated with a random procedure which does not at all aim at the goals of the final selection. The last named logic is, in fact, the same that has governed the origin of species through natural selection, as has been explained by Charles Darwin.

An efficient use of the trial and error method requires a large number of alternatives, perhaps hundreds of them, and the range of their variation must be so wide that it includes at least one potentially fruitful alternative. Note that we need not yet find a perfect final proposal among the alternatives. Finding one or a few promising ones usually suffices, because a few imperfections in them can normally be corrected later quite easily with iteration, for example. You should thus evaluate the alternatives not as such, but as potential starting points for proposals. Great competency of the evaluator is thus essential.

For developing a large number of alternatives two methods are common:

For generating a large range of alternatives you might like to take an existing product as a starting point, but the difficulty in this method is that the proposals tend to remain too close to this origin and really new alternatives are never found. Nevertheless, the method is viable when combined with bold wilful variation, for example by modifying the existing product idea with transformations such as:

You should avoid criticizing the transformations or slowing down the process, because it might spoil the innovative spirit of the team. For this reason you should disregard all practical viewpoints and restrictions. Their turn comes later, when selecting the best candidates and improving them further.

Another method for encouraging variation when developing alternatives is to let random "distant ideas" merge into the creative process. These distant ideas could be introduced as items randomly picked from a prefabricated list which need not have any relevance with the problem in question. However, each distant idea when associated with the original product may help to produce new ideas by analogy.

Once a thinkable proposal - or a few of them - has been found with the "trial and error" method, it quite often turns out that there still is much to be improved in each proposal. For these final ameliorations, iteration is often a suitable method.

4. Subconscious maturing and innovation. All the methods described above were meant to be used by the designer as planned and conscious procedures, but another possibility is to let the designer's subconscious to take care of the work, perhaps by utilizing some fragments of the above logical chains or any other that we do not yet know.

The method of subconscious maturing and innovation is common in the artistic design of products. It is normal that the designer first lets the targets of the design mature in the subconscious for quite a time, and if all goes well, the solution eventually pops up. Such an event has been described by many professionals practising various arts, for example Mika Waltari (1980, p.398...400), writer of the best-seller "The Egyptian":

"This intensive experience is brief, sometimes a few seconds, sometimes minutes. ... In advance of it, I had already devised many outlines for the future book, but all of them had seemed pointless ... This veritable flash, the genuine innovation resembles a mystic occurrence and it does not last long. Afterwards you can consciously try to understand it and make it clear to yourself. Only thereafter you can start to collect new material from a novel point of view, and then follows the final concentration in writing which can take several years..."

Waltari emphasizes that the best arrangement comes from the subconscious, not by forthright planning on paper even in the case that the work will be based on a lot of collected written information:

"If I write down collected facts in a manner too definite, it becomes an impediment... It is better to let this collected intelligence submerge into the subconscious, and later when I really need these elements for my work, they will come back to conscious thinking as evident facts. If I should this way forget some details, I have concluded that those particulars were perhaps not really important after all. ... If I would try to write down longer passages [before their due time] their idea would die: the thought would stiffen prematurely so that I could no more exploit it." (ibid. p.406.)

Some creative artists believe that it would be detrimental to disturb or try to speed up the workings of the subconscious. The most ingenious ideas are the most elusive: they easily fade and disappear if the innovator too rashly formulates them in language or by drawing:

"In hunting for ideas man's skill at staging represents the hunter's craft. Creativity is a question of staging a problem with such a setting, that something begins to happen, appear, and move within it. Now a being is "becoming" there, something becomes more visible, more credible. But it is only loosely trapped; it can escape if one approaches it too soon." ... "The seizing of an idea is a process which one doesn't seem to be able to influence consciously. Conscious cognition is too coarse an instrument." (Pietilä 1985 p. 26.)

As a matter of fact, we know very little of the working habits of our subconscious. It seems that to beget an invention the brain needs, beside the logical basis for the problem solution, also stimulation which the inmost layers of the brain normally produce all the time. This stimulation is in no way related to the conscious problem and (because we do not know its structure) it appears to be random. On the basis of these two stimuli (logical and random) the brain then produces tentative solutions for the problem, and cognition then starts to evaluate these in the same way than the natural selection screens out the unfit mutants in Darwin's theory. Eventually one of them becomes accepted in the conscious evaluation and the artist starts developing it further.

Admitted that we do not know how innovations are born, it is nevertheless possible to stimulate innovation, at least in team work. Special techniques that have often been used for stimulating innovation, include:

All these methods share a few common principles:

The participants should try to forget attitudes which could inhibit innovation, such as (according to Johnsson and Varjoranta, 50):

Participatory Design

The methods discussed above are suitable for industrial mass production where the future users of the products are normally unknown and unable to take part in the procedures of product development. There are, nevertheless, many situations where the users are well known and participate actively in the process of design, which can in fact bring about several advantages as compared to professional design without participation:

A disadvantage of participation is that much time must be spent in the meetings. Time is needed for settling disagreements between the users, if they are many, and for explaining the designer's proposals. These proposals often have to be presented as expensive prototypes, because many users cannot understand theoretical concepts and prefer discussing existing products or realistic mock-ups.

Close co-operation between the designer and the user of the product has its roots in the ancient method of the artesan, and even today it is much used in one form or another. Some typical approaches of it are discussed below.

Tailor-made design is the normal arrangement of co-operation for producing a unique product for one person or for a small group of people such as a family. When it is possible to gather all the designers and users of the product around a table, they can work as a team, deliberating together the problems of design. The solutions to the problems are often found and accepted collectively, but it is the task of the professional designer to explain the technical restrictions and to produce alternatives, perhaps with the methods of professional design discussed earlier. The designer is normally hired as a consult by the user.

When a large but unorganized cluster of people are willing to develop the product in co-operation, suitable methods can be found under the label of collective design, which method has sometimes been used when planning a neighborhood of houses, see Kukkonen (1984). It is not very common, but it can have some interest from the viewpoints of research and democracy.

Collective design is based on regular meetings of the designers and the future users, the number of which can amount to several hundreds. Because of the great number of users of the product, their opinions often differ, and a discussion to settle the conflict is called for. In order to speed up the discussion it can be advisable to organize the participants into temporary "interest groups". Beside these groups, there is always a "technical team" of professional designers (and possibly researchers) who continuously prepare alternative proposals to be discussed in weekly general meetings with the users.

Typical phases in the project are:

  1. Organizing the interest groups who then can decide to have private meetings if they feel it necessary.
  2. Analysis. The interest groups clarify their goals, first only to themselves.
  3. Design and negotiation between the interest groups. If a group seems to be suffering because of a proposal this group should perhaps receive a compensation for it.
  4. Ratification with so unanimous a decision as is possible. In more detail.

It is the task of the technical team, beside preparing the proposals, also to provide a "design language" so that all the participants can define their expectations and can understand the proposals of the technical team. For example, Kukkonen (1984) used a miniature model system in scale 1:15 for the design of the interior of the dwelling (see picture of it). This scale had the additional advantage that ready made doll house furniture could be used in it.

A pioneer work was the concise book Toward a Scientific Architecture by Friedman (1975). The writer states that to assist collective design, the designer must, in advance, prepare a repertoire that shows the user all the possible alternatives he has. Moreover, the repertory must contain warnings pertinent to each choice, e.g. its benefits, inconveniences and costs. But it is not up to the designer to criticize the choices of the user any more than the waiter of a restaurant criticizes the dishes his client chooses.

A well-known example of theoretical material, in advance prepared for collective design, is A Pattern Language (1977) developed by Christopher Alexander et al. It is based on research both with regard to practicality and to comfort. The "pattern language" consists of 253 design instructions or patterns. Each of these follows the same formula, described on page x of the book. The first picture is always an archetype-like example and there is also a short list of other forms that it is related to. The list is followed by a caption that clarifies what this pattern is all about. After this, an account is given of the empirical knowledge about the pattern and the variations of its application. An example of Alexander's patterns. The method of collective design with these patterns is explained in The Oregon Experiment, by Alexander et al. (1975).

Thanks to intensive research, some products possess now so reliable a theory that designing new products is quite easy. Some researchers, notably Yona Friedman (1975 B) and Nicholas Negroponte have proposed that on the basis of such a theory - the standards, algorithms, exemplars and rules of fine-tuning them - it would be possible to construct a design machine, a computer programme or an apparatus for producing designs for new products automatically. The benefit would be not only reducing the work of design, but to improve the service to the consumer who thus would have more options when buying a product.

There are few design machines in operation today, but they may become more frequent in future. The idea is theoretically interesting for researchers, because an explicit theory of design will be needed for defining the costs and other results that each alternative in the menu will produce when selected, and of course, for producing the design that the customer finally wants to order.

It is not difficult to construct a design machine for such products which consist of prefabricated parts and the customers need only choose the components they want to include in the product. In fact, this is what today already happens, not only in the traditional coffee maker, but also in the marketing systems of kitchen furniture and of computers, especially when bought in the internet.

The next step could perhaps be enlarging the customer's selection to include dimensions, colors and shapes of the product as well, and to transmit the finished design to the machines of manufacturing, thus connecting to the system of computer-assisted manufacture (CAM).

Design as the final phase of research. Usually the initiative to a participating design project comes from the people that need the new product, but there is also the possibility that a professional designer or researcher wants to combine research and design, for example by continuing a descriptive research project with proposing a novel design for the object that has been studied, and on the basis of the information that has been collected.

An excellent example of combining research and design is Sirkka-Liisa Keiski's project (1998) for developing a new type of fixed furniture for kitchens. She first interviewed and observed a group of old aged people in their home kitchens, then she constructed a mock-up kitchen and finally tested and improved it during a second interview session. A photo of the mock-up.

The www-pages on the development of an industrial product:

  1. Logic of Product Development
  2. Analysis in Product Development
  3. Synthesis in Product Development (this page)
  4. Evaluation in Product Development

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August 3, 2007.
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Original location: http://www2.uiah.fi/projects/metodi