Functional design refers to the design process of creating practical value of products based on the potential needs of users, through functional cost pricing analysis, by professional and technical personnel to design products, enterprises to arrange production, carry out targeted marketing, and deliver products to target consumers. Function means that when designing a product, the purpose and utility of the product should be considered. Functionality is the first principle of modern design. Here, function includes several levels: as far as product function is concerned, it refers to its function, efficiency, purpose, use, etc. At the level of human work and activities, it refers to the purpose, task, homework and operation.
Section 1 Product Function Classification
The functionality of modern design has its rich connotation, and the function is different for different product design objects. Generally speaking, according to the importance of function, it can be divided into basic function and auxiliary function; According to the functional nature, it can be divided into material function and spiritual function, or use function and taste function. Here we explain the design function according to the latter classification (Figure 4- 1).
Figure 4- 1 product function classification
I. Material function
The material function of industrial design includes the physical function and practical function of products.
(1) body function
Physical function refers to the performance, reliability, safety and stability of product design.
When people buy TV sets, refrigerators, air conditioners, electric bicycles and other electrical appliances. They will first consider whether the product is safe to human body, and often choose products with low radiation to human body and high safety factor. From primitive people using stone tools as weapons to prevent the invasion of wild animals to modern weapon design, we can see that security is a human desire. If any kind of design lacks safety and reliability, it will cause people's worries and make the application of products resisted by social consumer psychology.
The physical function is also reflected in the durability of the design itself. In the process of use, quality is an important symbol of product performance and stability. Products that can't be used for a long time, whether for consumers or producers, will cause waste and loss, and the culprit is the designer.
In addition, the cognition of industrial products is also an aspect of physical function, that is, whether the designer's design is easily recognized, whether it can accurately convey information, whether it is easy to use and whether it is simple and convenient to operate. The more concise, convenient and simple the operation, the stronger its applicability. At present, some domestic manufacturers like to use foreign language labels to express the internationalization of their products, but they give
It has brought inconvenience to the lives of many people in China. Therefore, designers should try to avoid such problems when designing.
(2) Practical function
Practical function mainly refers to the convenience, comfort and agreeableness of designing products.
Figure 4-2 Tomb of Tutankhamun, Egypt
From the throne of Knossos Palace in Crete, to the throne of Versailles Palace in France, and then to the throne of the Hall of Supreme Harmony in the Forbidden City in China, these seats are basically designed to improve the majesty of rulers, not to reduce the tension of their back muscles. Although magnificent, it rarely considers ergonomic factors. With the development of science and technology and the continuous improvement of people's material living standards, people have higher and higher requirements for the comfort and amenity of products. Designers pay more and more attention to the physiological function of products in design, which is also a major aspect of "people-oriented" humanized design.
Taking computer design as an example, the practical functions of the product include whether the computer operation interface conforms to people's habits, whether the keyboard will make people's fingers feel tired, and whether the angle of the display conforms to people's visual habits. Industrial designers use the knowledge of ergonomics to find out the existing problems of products or new demand points of users, and use design means to solve these problems, so as to realize the convenience and comfort of products and reflect the humanized care of products for users.
The leisure bedding (Figure 4-3) designed by Italian designer Levint in 1997 has aroused positive reaction in the market because of its comfort. This design can be called "truly comfortable design", which makes people feel comfortable enough to sit on it and fall asleep safely. Eero Saarinen, a famous American architect and industrial designer, is also very successful in furniture design, especially in chair design. He applied ergonomics to the design and designed this chair.
Figure 4-319 Leisure bedding designed by Levint in 1997.
Can conform to the corresponding parts of the human body (mainly including back, hips, waist and legs), and it is very comfortable to sit. At the same time, it also reduces the health hazards caused by labor, reduces the occurrence of cervical spondylosis and lumbar spondylosis, and is well received by the public.
Figure 4-4 Tulip Chair Eero Saarinen 1956
Second, psychological function.
Spiritual function is aesthetic, symbolic, educational and other functions expressed through design appearance and material function.
From design to production, the aesthetic function of products always exists with practical functions. Once the creator's image is transformed into a concrete form of existence-product, it will inevitably become an aesthetic object with aesthetic functions.
(A) aesthetic function
The aesthetic function and practical function of product design are organically linked, which can attract people's attention in particular. At the same time, the competition of design is inseparable from aesthetic value, which is mainly reflected in the similarity and homogeneity of product design.
The aesthetic function includes the psychological feelings brought by the elements of product design, such as modeling, color, texture and decoration. Product design not only has practical functions, but also can arouse people's aesthetic feelings through its external forms and meet people's different aesthetic needs. This aesthetic function is a spiritual function based on material function, which can also be called psychological function. For example, in product design, surface selection emphasizes surface decoration such as material texture, wood texture, metal texture, etc., and is processed by precise technology to show the texture effect or true color of the material. This pursuit of natural modeling and texture effect often brings people a brand-new natural feeling and psychological pleasure.
The aesthetic function of product design is also reflected in the communication between designers and users. The product feeling formed by people's own aesthetic experience aims to meet people's psychological needs. The aesthetic feeling of modern product design is mainly determined by two factors:
First, people's ideas about the beauty of product shape, color and surface;
Second, different people have different psychological feelings.
Figure 4-5 is selected from the industrial product design exhibition of new york Design Week in 2005.
Specifically, the overall effect of excellent product design-line, texture, color, light and shade, shape combination, etc. It constitutes a "meaningful form", which appeals to human visual organs and tactile organs, giving people emotional pleasure and beautiful enjoyment (Figure 4-5).
Symbolic function
Symbolic function is an important part of spiritual function, which refers to the symbolic function of product design, arousing people to recall past experiences and feelings and showing some special significance.
Figure 4-6 Modular wine rack (multi-splicing, ABS plastic, Gideon Dagan design)
Industrial product design generally achieves its efficacy through aesthetic factors such as modeling, color, decoration and texture.
A product design that embodies the efficacy of a specific location and a specific group of people is called a status symbol; Designs that are of special significance to some users are called artificial symbol designs, which are based on the practice of a specific society. Although identity symbols can represent the identity of a few people in a certain period of time, with the passage of time and the sharp increase in the number of users, the original identity symbols will be lost and new identity symbols will be produced. Therefore, the research on systematic consumption behavior abroad proves that if the reputation of a designed product is recognized by the society, the added value of this designed product has the possibility of meeting the new needs of consumers. Such as Porsche, Mercedes-Benz, Chrysler, Ferrari and so on. World famous cars can become the object of people's competition because their symbolic significance is far greater than their practical value.
Figure 4-7 Pagani Zonda (designed by Mode na Design Studio in cooperation with Ferrari Racing Manufacturing Company)
Figure 4-8 Bugatti EB 16.4 Veyron (one of the most expensive cars at present)
Section 2 Function Analysis of Product Functions
The first essence of design is function, and various functional values are the first goal pursued by design. Functional analysis in design is a scientific method developed in the process of practicing this goal. It analyzes and combs the functions pursued by the design in detail, makes a functional system diagram in the way of system engineering, forms a complete, detailed and efficient structural conceptual design, and finally completes the design task.
Product function analysis is an important part of product design function methodology, which mainly studies the relationship between function and cost, seeks the most reasonable corresponding ratio between function and cost, and achieves the greatest economic and social benefits with as little cost or consumption as possible, and improves the value of design objects.
The functional analysis of product design mainly includes the following aspects:
The first is to determine the degree of technical function, which is generally expressed by the performance parameters of the product;
Secondly, the product function cost analysis, that is, to find a lower cost scheme among various feasible design schemes with the same function; Thirdly, the quantitative and qualitative analysis of product reliability laid the foundation for the new design scheme.
Functional analysis is mainly from thinking about product structure to thinking about its function, so as to form new design ideas and put forward creative design schemes, which are not bound by the existing morphological structure. For specific product design, function refers to the efficiency, use and function of the product.
Usually, the same product can achieve different functions by using different attributes under different conditions. When designing products by functional analysis, we should follow the following steps: (1) abstract design tasks, determine general functions, grasp the essence of products, expand our thinking and find various methods to solve problems; (2) Decompose the total function of the product to be designed into sub-functions and functional elements; (3) Find the solution of sub-function (functional element); (4) Combine all the schemes to form a variety of design schemes; (5) Plan evaluation and decision-making.
First, determine the overall function.
1. abstraction of product design tasks
To determine the overall function of the product, it is necessary to abstract the product design task. For example, shearer can be abstracted as equipment for material separation and displacement; Trucks can be abstracted as a tool for transporting materials over long distances; Dishwasher can be abstracted as a device for removing dirt from tableware. ...
The way to abstract product design tasks is to list a variety of needs and desires in the design task book. In the process of abstraction, we should grasp the essence, highlight the key points, eliminate the secondary conditions and fully develop the main parts. This paper mainly describes the design tasks, and does not involve specific solutions. For example, design a walnut ditcher, and the abstract expression of its design task is described as follows:
If the word "crushing" is used, it has already hinted at the solution. At the same time, considering the external pressure, the methods of "squeezing", "pressing" and "clamping" can be adopted. If we think horizontally, we can imagine whether the walnut skin can be crisp, so it is easier to open, and so on, which can help us solve the problem that the essence of this product design is from "broken shell" to "separation of shell and kernel" Therefore, a more abstract expression may get a broader answer.
Figure 4-9 Walnut Clip
2. Black box method
By observing the outside of the unknown system of the designed product, the input and output between the system and the environment are analyzed, and the functions and characteristics of the product system are determined through the conversion relationship between input and output, so as to further seek the working principle and internal structure needed to realize the functions and characteristics. This method is called the black box method. It is generally applied to the functional analysis of large-scale industrial product design.
Second, the total functional decomposition
The total function of the product can be divided into sub-functions (or primary sub-functions, secondary sub-functions ...), and the sub-functions are further divided into functional units (smallest units). So the function is hierarchical and can be decomposed layer by layer.
(a) functional elements
Functional elements are the basic units of product functions. The basic functional elements used in industrial product design are: physical functional elements (physical basic actions of energy, matter and signal changes in the system). Mathematical function elements (reflecting the basic operations of mathematics, such as addition, subtraction, multiplication and division, multiplication and division, etc.) are mainly used for mechanical addition, subtraction, multiplication and division, such as differential gear trains and mechanical computers. Logical functional elements include AND, OR and NOT ternary logical actions, which are mainly used for control functions.
(2) Functional structure
In the process of product functional analysis, the diagram expressing the sub-functional relationship is called functional structure diagram, which can clearly show the starting point and thinking of product design and is the way to reflect the functional requirements of products in design. The general functional structure diagram consists of the following three basic structural forms:
The (1) sequence structure, also called sequence structure, reflects the causal relationship between sub-functions or the relationship between time and spatial order. (2) Parallel structure, if a goal is achieved by several sub-functions, or the next sub-function can only be continued after some sub-functions are completed at the same time, then these sub-functions are parallel.
(3) Ring structure, also known as circular structure, the feedback of output structure is the circular system of input structure. This structure is analyzed according to logical conditions, and it will be repeated when certain conditions are met.
Create a product functional structure diagram:
(1) Through the analysis of the technical process, the boundary of the technical system is defined and its total function is determined.
(2) Divide functions and functional elements. Usually, the function and function of the main workflow should be considered first. For specific methods, see functional decomposition.
(3) Establish a functional structure diagram. According to the physical function principle and experience of the product or referring to the existing similar systems, the order of sub-functions or functional elements related to the process is arranged first, usually a rough plan is put forward first, then the relationship between them is checked and improved, and then other parts are supplemented. In order to choose a better scheme, several different functional structures should be considered at the same time.
(4) Compare and choose the best functional structure scheme. The aspects of evaluation generally include: the possibility of realization; Complexity; Whether it is easy to get a solution; Whether it meets the specific requirements, etc. Usually, several better schemes can be further concretized until the best scheme is found.
(3) Functional element solution
Solving functional elements is an important "search" stage in product scheme design, that is, finding the technical entity-functional carrier to realize product functional elements. The basic idea of functional element solution is: function-working principle-functional carrier.
The commonly used methods are as follows:
(1) Intuition method: Intuition method is that designers rely on personal wisdom, experience and creativity to seek various functional solutions of products.
(2) Investigation and analysis method: Investigate and analyze the existing industrial products, such as the prototype of this model, and analyze the function and structure, which are advanced and reliable? What are outdated and need to be updated and improved? This is of great benefit to the development of new products, the conception of new schemes and the search for the original understanding of functions.
(3) Design catalogue method: The so-called design catalogue method (also called solution catalogue) is a table or classified data that integrates various principles and structures to achieve a certain function.
In addition, the solution of function elements (subfunctions) requires rich practical experience, careful observation, smooth association and certain opportunities.
Thirdly, variation analysis.
The systematic analysis of the development and change of parts, mechanisms and forms of products is called variant analysis. This is a dynamic analysis method. The purpose of variant analysis is to sort out the evolution process of product parts, structure and form according to certain principles, so as to sum up the change law, find out the direction of further development, find out the blank points, and design new products in time to fill the blank.
Figure 4- 10 Memory with Shape Changing with Storage Capacity
Through variation analysis, the method of product variation operation can be summarized. Provide the main clues for the development of this product. Then develop new products according to certain working principles. Products that have made major breakthroughs in the development process are called improved products.
Variant analysis is to analyze the evolution law of products, mechanisms and parts from the dynamic aspect, and provide the basis for determining the development direction of products and judging the optimal solution of sub-functions. They will provide useful tools for product design.
Fourth, the principle scheme synthesis
Principle scheme synthesis is the process of synthesizing sub-functional schemes into a whole scheme to realize the total function. Here we focus on the related content of morphology, which is especially important for the designers of products.
In the stage of function analysis, after determining the sub-function of the product, through the solution of the sub-function, and then through selection and variation, some alternative schemes of the sub-function carrier are obtained. In variant analysis, we have a clear understanding of the development of main functional schemes and a general understanding of the position of each alternative scheme in product development and evolution; On the basis of these works, the sub-functional schemes are combined to seek the optimization of the overall scheme.
Morphological synthesis method is based on morphology and finds various answers through systematic decomposition and combination.
Functional solutions must be compatible, otherwise they cannot be combined; Give priority to the better solution of the main sub-function, and choose other compatible sub-function solutions from this solution; Reject the design scheme that does not meet the design requirements and constraints or is unsatisfactory, such as high cost, low efficiency, serious pollution, unsafe and difficult processing.
When selecting a few schemes from a large number of feasible schemes for further design, inheritance and innovation are a pair of contradictions that run through the design process, and designers should handle these contradictions well.
Functional analysis has many advantages in product design:
(1) It always takes the function of the product as the design core, and the design idea is mainly the functional system;
(2) It is an innovative design method, which can overcome the bondage of single thinking mode;
(3) Unnecessary functions can be effectively eliminated in functional analysis, thus reducing costs and realizing product value efficiently;
(4) The function-centered design method ensures the practicability and reliability of the product to the maximum extent;
(5) Integrating functional analysis into system thought and combining functional analysis with product modeling elements provide new design ideas for product design.
Starting from the function, using the concepts and methods in system engineering value, systematically constructing and analyzing the technical ways and means of materialization of design objects will help to overcome the shortcomings of traditional design methods that only design from product structure and modeling, and make the structure between design functional elements more reasonable.