Out-Patient Charging System Based On 3-tier

The information of the hospital is an important part of the current tradition industry information. Whether is the challenge of the hospital management and the business process that SARS (Severe Acute Respiratory Syndrome) in the year of 2003 brought, or the demand of the treatment service that people making, all require hospital to improve the service quality through changing the traditional management and the operation mode by the information of the hospital.Hospital Information System belongs to one of the most complex enterprise information systems hitherto. Construction cycle of traditional HIS based on Client/Server is long and function is not perfect enough. They have generally the phenomenon and questions that system responds slowly, centralized control is difficult and reliability is poor. So it needs one kind of scientific method to analyze and design Hospital Information System. Out-Patient Charging System that this paper will talk about adopts object-oriented modeling technology and method which can more deeply catch the requirement of users and set good base for successful development of this system and software and maintenance during later stage. It is 3-tier Client/Server structure and COM+ technology adopted in development process that make the system abbreviate, scalability and security greatly.After studying the systematic structure development course, the paper introduces client/Server structure and its shortcoming. Client/Server lays user interface and business logic in the client. Though the structure is simple, it brings the intrinsical questions that system responds slowly, centralized control is difficult and reliability is poor. Secondly, in the paper, we introduce 3-tier structure and its excellence. It divides application system into three tiers: users interface tier, business service tier and data service tier. User interface tier offers user interface, mainly gathers data submitted by user, checks data format, uses operation provided by component in the business service tier: disposes data returned by component, displays data in the user interface. This tier is developed by Delphj7.0 language. Business service tier takes charge of dealing with application request of user interface tier and accomplishes business affairs logic calculation task, then returns the result to users. Business service tier is separated from the business logic of client. It concentrates on server parts and shares for all users. The independence of business logic and three features of the COM+ component: language independence, process transparence, reusability solve the intrinsical problem of Client/Server Structure. Business service tier is a kernel part of the whole application. Data service tier offers data source for application. This tier uses MS SQL Sever 2000 to store data.After mastering structure based on 3-tier Client/Server/Server, we can use it to design system. After analyzing main business logic and workflow of Out-patient Charging System, we design database with the rule of assuring integrality of the data.After finishing system design, we regard this as the blueprint and realize Out-patient Charging System progressively. During process of realizing, we have met a lot of key technology relevant to component development. We have given the realizing method and the key codes of every tier in 3-tier structure. Then we discuss holding fault character of application server, problem of visiting right, systemic expansibility and maintainability and give the relevant scheme. At the end of this paper, the whole paper is summarized, and the running effect of the system is talked about and the requiring prefect sides in the designing process are raised.