Design And Implementation Of Configurable Evaluation System For Real Estate Transaction

Since 2005, the status of the housing stock transaction in the real estate industry was more and more important in our city. From a view of practice, the problem existing in the real estate transactions mainly concentrated in the housing stock transactions. The tax collection and administration of the housing stock transaction involved many tax categories, which made it more difficult to collect and administrate. Additionally, there are many loopholes in the regulation of the tax bureau in housing stock transactions. Some tricks appears constantly,for example, twin-contracts, fake giving real sell, replace sell with lease, notarized but not assigned, irregularities of evaluation, and so on. According to incomplete statistics, only in 2009 our city had nearly hundreds of millions yuan tax erosion of the housing stock transaction caused by the above problems, and perhaps this was just the tip of the iceberg.So, the State Administration of Taxation has determined that not only the local tax department and the management of relevant taxes need to keep the communication and coordination, but also to unified the identification of the real estate transaction price. How to solve the problem of tax collection is becoming the top priority in the work of real estate tax collection. Through the use of computer system to evaluate the information of real estate transactions, we can set up an efficient, accurate and flexible evaluation platform.There is two core of building the evaluation system for housing stock transaction. The first one is how to gathering data and analyzing it, and the next one is to build a system architecture with flexibility and security. With this goal, ths article introduces the methods and principles of property assessment, the situation of CAMA in the world, and the reason of keeping the configurable ability of system. It especially analyses three methods of property assessment: the market comparison approach, income capitalization approach and replacement cost approach. Finally, the access control technology has been discussed in the paper.Next, this article elaborates the purpose of the subject into three aspects, that is the configurable ability of the assessment methods, processes, permissions. First of all, set-up theoretical basis which is used for mass appraisal, for example, the evaluation model, which base on the theoretical to widely collect information about real estate transactions and real estate basic information. Then choose some transaction instance accord with certain conditions as comparable instances to establish the prices comparable basis. And through a series of processing establish a reliable assessment model for the final assessment. Secondly is to implement the configurable system architecture. On the macro system level, in accordance with the requirements of the workflow model, we decomposed the whole evaluation process into various modules on the basis of analyzing and understanding workflows and realize the connection between the modules through the data exchange technology. Thirdly is system control by using the access control technology. The main work is to design the basic permissions distribution strategy and authorization rules, and to divide the basic permissions and roles according above system modules.Completed the design phase, this paper mainly focus on the concrete implementation of system. By the display of UML class diagram, sequence diagram and component diagram, it embodies the realization process of assessment system step by step. Then it describes the development environment and system architecture of the whole system focuses on the network topology and the system interface, including building the physical link between the management system, formulating the safety equipment deployment scheme and security policy. Finally, this paper has a summative description about how the system is applied to the evaluation work.At the end of this paper, we introduce the method to test the function and performance of the evaluation system. The test case applies to the idea of black box testing and bases on the real estate information which is collected by preparation research. Each sub-module passes the test and meets the design requirements, and the test reflects some shortcomings of the system.