【文章內(nèi)容簡介】 be the product fully in terms of functional needs and physical limitations. These functional needs and 吉林化工學(xué)院畢業(yè)設(shè)計(jì)外文翻譯 7 physical limitations will form the product specifications. Surveying prospective purchasers or customers could collect information required to identify customer needs. Conducting a marketing study that begins by establishing target markets and customers can do this. Then customers’ wants and needs could be obtained by using several methods such as interviews and questionnaires. Also, similar products (petitive products) are investigated to find possible improvement opportunities by focusing on weakness points and desired features by customers. Next, customer wants and needs are arranged into groups and prioritized according to their importance. Needs analysis usually results in a statement of recognized needs and the expected manner in which that need should be met. . Product Requirements Analysis Results of the needs analysis step are used to identify the product requirements. The development group begins by preparing a list of functional objectives needed to meet the customer’s primary needs. Further analysis of customer needs reveals operational functional requirements that impose both functional and physical constraints on the design. Secondary customer requirements will be categorized as general functional requirements。 they are ranked secondary because they will not affect the main function of the product. That is, a product may lack one or more general functional requirement and still be considered as a functional product that meets the intended function. General functional requirements should be weighted with respect to their importance. . Product Concept Analysis Product/concept analysis is the deposition of the product into its basic functional and physical elements. These elements must be capable of achieving the product’s functions. Functional elements are defined as the individual operations and transformations that contribute to the overall performance of the product. Physical elements are defined as the parts, ponents, and subassemblies that ultimately implement the product’s function. Product concept analysis consists of product physical deposition and product functional deposition. In product physical deposition, the product is deposed into its basic physical ponents which, when assembled together, will acplish the 吉林化工學(xué)院畢業(yè)設(shè)計(jì)外文翻譯 8 product function. Physical deposition should result in the identification of basic ponents that must be designed or selected to perform the product function. Product functional deposition describes the products overall functions and identifies ponents functions. Also, the interfaces between functional ponents are identified. . Product/Concept Integration Basic ponents resulting from the deposition process should be arranged in modules and integrated into a functional system. The manner by which ponents are arranged in modules will affect the product design. The resulting modules can be used to structure the development teams needed. System level specifications are the oo one relationship between ponents with respect to their functional and physical characteristics. Functional characteristics are a result of the operations and transformations that ponents perform in order to contribute to the overall performance of the product. Physical characteristics are a result of the ponents’ arrangements, assemblies, and geometry that implement the product function. Physical and functional characteristics, forming the system level specifications, are arranged into a hierarchy of descriptions that begins by the ponent at the top level and ends with the detailed descriptions at the bottom level. Bottom level descriptions (detailed descriptions) are used to determine the relationships between ponents, 1 if the relationship exists and 0 otherwise. This binary relationship between ponents is arranged in a vector form, “ System Level Specifications Vector”(SLSV). System level specifications identified in the previous step affects the general functional requirements in the sense that some specifications may help satisfy some general functional requirements, while other specifications might prevent the implementation of some desired general functional requirements. The impact of the SLS on GFR’s should be clearly identified which will help in developing products that will meet, up to a satisfactory degree, the general functional requirements stated earlier. The impact will be determined based on –1 as negative impact, 0 as no impact, and 1 as positive impact. A negative impact represents an undesired effect on the general functional 吉林化工學(xué)院畢業(yè)設(shè)計(jì)外文翻譯 9 requirements such as limiting the degree to which the product will meet the general requirement, or preventing the product from implementing the general requirement. While a positive impact represents a desired effect that the SLS will have on the general requirements, such SLS will ensure that the product will satisfy the requirements and result in customer satisfaction. An SLS is said to have no impact if it neither prevents the implementation of the GFR, nor helps satisfying the GFR. The degree of association between ponents should be measured and used in grouping ponents into modules. Incorporating the general functional requirement weights can do this, in addition to the system level specifications vectors and their impacts on the general functional requirements to provide a similarity index between ponents. The similarity indices associated with ponents are arranged in a ponent vs. ponent matrix. Components with high degree of association should be grouped together in design modules. This can be acplished by using an optimization model that maximizes the sum of the similarities. The optimization model will identify independent modul