Improvement rate based on quality and technical characteristics of the parallel optimization model

Paper Keywords: quality of technical characteristics, quality function deployment (QFD), customer demand, optimizing model
Abstract: The goal of user needs objectively reflect the quality and technical characteristics of the product is quality function deployment (QFD) Application of the important content. This target based on user demand and the QFD house of quality established information technology is proposed based on product quality Parallel optimization features to improve the rate method, a check valve in parallel optimization model quality and technical characteristics, quality check valve has been optimized to improve the rate of technical features for Applications such products QFD method provides a scientific basis for improved design.


QFD (Quality Function Deployment, referred to as QFD) is a user-driven product development and quality assurance methods. It uses a systematic, disciplined approach to investigation and analysis of customer needs, using a structured framework to convert it to products development of the various technical features of information, making the design and manufacture of products to truly meet customer needs.

QFD through the technical features of product quality index value of the improvements to meet customer needs, improve the user for new or improved products, product design satisfaction. In product design or improvement of the process, a user needs assessment for the improvement target, through the quality characteristics associated with improved performance to get. In order to improve the product, must accurately describe the target user needs assessment and specific indicators of the quality characteristics of the intrinsic relationship between the values. To accurately describe User needs assessment and quality characteristics of the target value as a function of the actual implementation there is a big difficulty. because they are in different scales, the former belonging to the order of discrete or continuous scale, the latter is not, and indicators of the quality characteristics of each unit of measure is not the same. the expression of a non-sequential order of the variable scale parameter identification, especially when the increase in quality feature, you also need to redesign the system identification data, system identification, which in practice Application is clearly unreasonable. In order to solve optimization of quality and technical characteristics of the parallel faced this problem, based on the quality of technical features to improve the rate of the optimization strategy is an effective method.

1 quality function deployment
Quality Function Deployment (QFD) in the 20th century, the late 60s, the Japanese scholar Yoji Akao (Akao Yoji), Professor the first time. The method is the integrated use of systems engineering thinking enterprises to improve product quality and competitiveness of the powerful tools. QFD is the customer demand for the product of the interpretation of multi-level analysis of design requirements into products, parts characteristics, process requirements, production requirements, quality engineering tools. Its basic idea is: in the product design or development process, all activities by the "Voice of the Customer" VOC (Voice of Custourer) drive, and the needs of the customer to the product design to reflect, under the premise of meeting the customer needs, full account of development time, quality, cost, service, environment relationship to achieve optimization.

Is the core of quality function deployment and comprehensive user needs to access, based on a scientific and systematic approach, the user needs is decomposed into technical characteristics, technical characteristics of parts and components, manufacturing process and quality control process feature. QFD most common four-phase decomposition method is: product planning (Product Pl arming), parts configuration (Parts Deployment), Process Planning (Process Planning) and production planning (Production Planning). It will be transformed into user needs layered product technical features, parts characteristics, process characteristics and production methods and a series of quality control can be measured, actionable events, activities or targets. for the development of product planning, process planning, production planning, and product and process of continuous quality improvement, provide decision support . In the expansion process, the output of the previous step is next input to form cascade decomposition process. Figure 1 shows, each decomposition stage corresponds to a house of quality.


House of Quality House of Quality planning process is divided into the establishment and the two processes in decision-making house of quality. The quality of decision-making part of the house is the use of the various parts of the house of quality information, concurrent optimization of quality characteristics determine the performance characteristics of each quality target. Therefore, the decision-making part of the house of quality is the key to the quality characteristics of product planning in the parallel optimization problem. through the quality characteristics of the quality characteristics of the optimized parallel target is QFD process of decomposition of the most important output is the development of new products and an important basis for improving existing products, and focus.

2 parallel optimization of quality and technical characteristics
2.1 The user needs to improve the rate and quality of the technical characteristics of the relationship between rate of improvement
Let yi, (i = 1,2 ... m) for the user needs to improve the rate, xj (j = 1,2, ... m) for the rate of improvement of quality and technical characteristics, the relationship between yi and xj of the following:

QFD house of quality established by the various pieces of information access and user demand to improve the rate of technical features to improve the quality of the optimized rate of performance under the original value of the product, you can determine the corresponding technical features to improve the target product.

2.2 Optimization of quality and technical characteristics of the parallel model
Linear programming is a solution of the importance of optimizing resource allocation method. Different quality characteristics of the parallel optimization strategies, corresponding to different linear programming optimization model. According to the linear programming of goal programming, combined with its product development objectives and possess various resources, make an effective product design and planning, while analysis and design of products to meet various goals and the extent of the gap. in the target planning, product development, all of the targets can be in one or several functions to be considered, Then the optimal solution. This process is the goal of these regulations the minimum deviation, that is close to the target maximum. does not meet with representatives of yi-i-goal from the goal differential, with yi + i on behalf of a goal than the first the amount of target deviation. These deviation variables must appear in the objective function and objective constraints.

Planning is only a single target if the target is called single-objective programming; have more than one goal called multi-objective planning. Qualitative characteristics parallel programming model for the single-objective optimization:

Where: i subscript for the needs of users, i = 1,2, ... m, j subscript for the quality characteristics,, j = 1,2, ..., fi that i-user demand and quality characteristics of the function, reaction the relationship between the house of quality matrix; gi for the first j two quality characteristics and function of other quality characteristics, reflected in the quality of housing in the correlation matrix; U characteristics for quality improvement and total cost required for a function unit; V for quality units required for the implementation of improvements and features a function of time; Rk for the addition to the cost and time other than product development resources constraint function; wi is normalized user demand for i-weight; xi for the first j features a quality improvement rate for multi-objective optimization of decision variables; Lj j a quality feature for the first minimum allowed rate of improvement; Mj for the first j months to improve the quality and characteristics of the maximum rate; Y 'i-user demand for the target rate of improvement; Yi the user does not meet the needs of i-goal from the goal of improving the rate differential; Y i-wide user needs beyond the goal of improving the rate of the target from the delta;; C for the implementation of pre-defined quality characteristics of the units can provide the total the upper limit of cost; T is a pre-determined quality characteristics of the implementation of the unit of time can provide the upper limit; b * for the addition to the cost and time of development resources outside the constraints of other products constant.

The model is based on user demand optimization model to improve the rate of the target, the aim is to make the user needs not met the target goal of improving the rate of the aggregate amount of the minimum deviation.

Example 3
Check valve to valve products as an example. Application of QFD method check for product planning, product planning house of quality in the nine identified user needs, are low noise, no leakage, small size, light weight, impact resistance, affordable, water loss is small, easy assembly and disassembly repair, safe, reliable, long life;; nine technical features, namely the principle so far Hui appropriate, seal, structure size, structure, strength, cost, flow resistance coefficient, parts standardization, reliability, service life. the user needs to be normalized importance degree processing, have normalized the important vector of user needs:
Links to Research Papers Download http://www.hi138.com QFD house of quality based on identified user requirements planning matrix to improve the rate of:

According to QFD house of quality information, to receive normalized user demand and technical strength of the coefficient matrix associated with the following characteristics:

The above equation (4), equation (5) and the coefficient matrix generation formula (2) and (3), check quality and technical characteristics are parallel optimization model is as follows:



Check the above optimization model is based on user demand optimization model to improve the rate of the target, which is used to check the user does not meet the needs of the target goal of improving the rate of deviation of the total amount of the minimum, taking into account the importance of the various user needs degrees. simplex method used check valve in parallel optimization model of quality and technical characteristics, quality and technical characteristics by improving the rate of check valve as shown in Table 1:

Calculated by optimizing over the rate of improvement of the quality characteristics of xj, it represents the quality characteristics of each item required level of relative improvement, the 1.0 �� xj �� 1.5, when xj = 1. 0, the understanding of "the quality of technical products the extent of the original features remain, not to improve "; when xj = 1. 5, then be understood as" product quality and technical characteristics of the improvements to be bigger, to reach the advanced level of similar products "; when 1.0 <xj <1 . 5, is understood as "product quality and technical characteristics of the improved degree of improvement between the first two to a value." This shows that the target to meet the needs of users should be given priority in the check valve -return principle, structure size, and reliability make major improvements; Secondly, we should in the structure strength and flow resistance coefficient and accordingly improve the service life; in sealing, cost, and standardization of parts and components may remain unchanged.

4 Conclusion
Improvements in product design, user needs to target for improvement, reflected in its objective of improving product quality and technical features, this is the QFD method to improve the design of Applications in the product key. According to established QFD house of quality information, improve the quality and technical characteristics established rates based on the parallel optimization model and solved, they will have quality characteristics for different levels need to improve the characteristics of items, make product quality for the next specific technical characteristics of the target provides the scientific basis. It is worth noting , optimization model is based on user demand information and quality of housing on the basis of the information, including the quality of housing information includes information about competitors of similar products, it is an integrated information, which directly affects the accuracy of the information for optimal results. Therefore, this method Early applications, accurate collection of all types of information is very important. Links http://www.hi138.com Research Papers Download