The hottest product conceptual design process base

The process model of product conceptual design based on triz/qfd/fa

at present, many computer-aided innovation technologies have been born, such as the research of using bond graph method to generate multiple design schemes; Support the functional structure decomposition research of conceptual design; Research on conceptual design based on QFD, among which TRIZ (abbreviation in Russian, English is eory of data problem solving) method is favored by Ken

1 conceptual design process model

conceptual design should first clarify the design requirements and conditions, and then generate a framework generalized solution, which is good at integrating design knowledge, manufacturing knowledge, business operation knowledge and other aspects, and finally complete the important decisions that affect the whole product life cycle

qfd is a very important tool used by enterprises to improve market share. It uses surveys, meetings, tests and other means to collect information related to customer needs and drive product design. At the same time, in combination with the design, production, capital and other resources of the unit and the market competition, the function, performance, success or failure, time to market, etc. of new products are decided, so that the enterprise products can obtain the maximum economic and social benefits while meeting the needs to the greatest extent. The main function of QFD is to determine the main problems and parameters of the product, clarify the priority and the relationship between each parameter and the final target value, and convert it into design and manufacturing information. Usually, HOQ (house of quality) is constructed in the form of matrix to represent user requirements, product functions and their relationships, as shown in Figure 1

Figure 1 HOQ structure

qfd realizes the management, guidance and control of the product development process through the analysis of various functions and activities of product development, as well as the description and transformation of the relationship between them, so as to ensure to meet the needs of customers to the greatest extent

any product must complete certain functions, so it is an effective way to design from the perspective of function analysis. When designing new products, before establishing the relationship between what, and how in the QFD matrix, the product functions must be decomposed and refined to basic functional units. Each what in the matrix should have an existing product structure function unit corresponding to it

through function decomposition and QFD methods, we can understand the customers. After too short-term use, you will find the needs and clarify the objective conditions of new product design. However, due to the interference of many factors such as the complexity of information and the fuzziness of the problem, it is difficult to clarify the essence of the problem, and we cannot quickly find a practical solution to the problem and a reasonable design approach. Therefore, the process of conceptual design needs to be improved by combining the ideas and tools of TRIZ theory and method

the flow chart of TRIZ problem solving is shown in Figure 2, which is divided into several processes, such as clarifying problems, classifying problems, solving problems, and determining evaluation concepts

Figure 2 TRIZ problem solving flow chart

according to the characteristics of conceptual design, using the theoretical method of TRIZ, combined with the application of qfd/fa, the conceptual design process model mainly includes the following five steps:

1.1 problem document and preliminary analysis

in order to obtain the demand data of QFD, it is completed by questionnaire

questionnaire composition:

1) system information: system name, system structure, main functions, system environment, etc

2) problem information: the problem to be solved, the mechanism of the problem, the history of the problem, the ideal result, etc

3) change system: allowable changes, change restrictions

4) available resources: matter, field, time, space, etc. acting on the system

5) problem solving history: other systems with similar problems

6) criteria for problem solving: expected technical and economic characteristics, expected schedule, expected degree of innovation, and other evaluation criteria

after mastering a large number of rich demand data, use QFD analysis data to clarify the demand level, understand the product status, extract useful information, and clarify the problem direction

1. 2 clarify the problem (formulaic expression)

the description of the problem is carried out on two levels, as shown in Figure 3. In the initial understanding process, we use professional languages such as the attributes and characteristics of the system to describe the system. With the deepening of understanding, it is effective to use functional languages to describe problems. In order to solve the problem, describe the system at the level of innovative language a (using TRIZ Method)

Figure 3 description of the problem

the formulaic description of the problem can make the problem solution clear and easy, and facilitate the formulation of the solution standard

1) problem modeling and knowledge transformation

for most people, the knowledge about special problems in their minds is difficult to write accurately and orderly on paper. The modeling process is to convert a large amount of intelligent data into an orderly set of knowledge units, and the relationship between units should be clear

2) innovation direction

the reason why complex problems are difficult to solve is that they cannot be solved only through a single operation, and often there are no results after countless setbacks. The experience of successful people shows that complex problems need multiple descriptions. Innovation direction is a set of simple problems used to describe complex problems. Dealing with these problems continuously is equivalent to approaching the solution of the problem from many aspects

3) ideal result

ideal final result IFR (ideal final result) is an important concept of TRIZ. Ideal final result is the solution of technical problems by mechanisms and constraints independent of the original problem. It can be simply expressed as:

ideal final result = the goal of 39 synthetic resin product replacement projects, 51 brands, and a total replacement of 800000 tons during the "1035" period of interest establishment/(cost + damage)

after understanding the clear problems of customer needs, we should first form the IFR of the products to be developed, which will help to break through the traditional psychological constraints and produce breakthrough creative results

1. 3 optimize the direction of innovation

TRIZ, as a science with 50 years of history and continuous development, has formed a set of structured knowledge. Compared with the brain storming method, it can concentrate the innovation ability on specific problems directly related to the final result faster, and quickly find the best way to solve the problem

1. 4 scheme synthesis

complex problems need to be decomposed into a set of multiple innovation directions, each of which is specific to a specific perspective. Each idea can also be changed manually; It cannot be expressed as the solution of the whole problem, but the whole set covers all possibilities. These ideas should be combined into new concepts. The classification and combination of innovative ideas should be based on the following constraints:

1) combine different ideas for the same function

each idea has its own advantages and disadvantages. The new idea after combination has all these advantages, and eliminate the disadvantages as far as possible

2) combine known systems

a. combine systems with the same functions. In most cases, there are multiple systems with different operating principles for the same purpose. Better results can be obtained through the compensation of advantages and disadvantages

b. combine systems with equivalent functions. The combination of peer-to-peer functional systems can get a more accurate solution

3) simplification

while combining ideas, functions and systems, it also increases the complexity of the duplicate standard of the design concept proposed by the National Bureau of building materials industry. Therefore, simplification is essential

1. 5 evaluation of results

1) satisfaction of evaluation concept standard:

the cost should not be increased, the output should not be reduced, the energy consumption should not be increased, the applicability should not be reduced, and the accuracy should not be reduced

2) reveal the potential failure possibility

3) formulate the implementation plan

2 apply TRIZ tools to solve problems in the process of conceptual design

2.1 solutions to conflicts

due to the dependency between system attributes, the change of one attribute often involves the change of other attributes. This conflict includes physical conflict and technical conflict. Through patent analysis, TRIZ Method abstracts 39 typical technical features that produce system spear back opposition. Any technical conflict occurs between two of 39 features. On the basis of studying patents, tshuller puts forward 40 principles that can be followed to solve technical conflicts. In order to clarify, four main solving principles are given for each conflict in the conflict matrix, as shown in figure 4

Figure 4 Application of conflict principle

2 2. S-field analysis

S-field analysis is a tool for modeling and TRIZ analysis of technical systems. It uses symbolic words to express system transformation, so as to clarify the key problems and find reasonable solutions. Any technical system has achieved certain functions, which can be expressed as an action system composed of object S1, action body S2 and field F. both are indispensable. Only by forming such a perfect binary structure, the system can effectively perform its functions. Here "matter" and The concept of "field" is generalized and can be used to describe various technical systems

a complex system can be described as a system composed of several "dihedral" intersecting. When a function in the system cannot form a binary structure, it indicates that there is a problem in the system, and it is necessary to introduce another substance or field to improve the system. By adding, deleting and modifying the elements of S-field diagram, the complex contradiction of the system can be effectively solved. S-field analysis method provides 76 methods to solve the problem of S-field model. According to these 76 methods, the problem can be solved conveniently and quickly

3 case analysis

a friction problem in the spinning mechanism, and its mechanism model is shown in Figure 5

Figure 5 simple mechanism model of spinning mechanism

1) problem

there is a simple reciprocating drafting mechanism in the lead device of spinning. Because friction will overheat the mechanism, the spinning speed is limited, and a faster speed is actually needed to increase output

2) system questionnaire

system information, system resources, etc. (omitted)

3) conflict in the system

shaft speed and friction heat

4) conflict theory

using the conflict matrix, the following features apply to the conflict:

a output (39, 39th technical feature)

b endurance of moving objects (15)

c speed (9)

d material loss (23) a

according to the conflict matrix, the most suitable principle is:

a changing the physical and chemical state of the object (35) refers to changing the hardness and surface structure of the object

b replaces mechanical system (28), such as electromagnetic system

5) key issues

6) system S-field diagram description and analysis S-field analysis diagram is shown in Figure 6

Figure 6 S-field analysis

refer to 76 standard solutions. To eliminate the harmful functions of the system, new substances (such as gas) and new fields (such as electromagnetic field) need to be introduced

7) results

change the hardness, density, material or surface quality of S1 and S2; Add a magnetic field between S1 and S2; Add gas and between S1 and S2