We have been working with a software company involved in developing medical applications, for various hospitals across the country.. These products are supported in different platforms. Currently they are in the process of developing Objects for NT Servers.
The Auditor performs auditing using claim, bill and line items as per the redefined business model. Since the product is client/server for NT clients and NT server, its an architecture of different layers. The core database component is Oracle or SYBASE engine on NT Server.

The database layer, business layer and the presentation layers are using VISUAL C++ objects, and the user layer uses the VISUAL BASIC objects.

The Data layer, takes care of the data communication between the back-end the engine and the front-end application. It uses the ODB connectivity and DA Objects to perform various database activities. MS-Access has been used for defining meta data which is the object for table mapping. Beyond these tools, such as metaman, an internal product is used to accomplish the job of class wizard.

The business layer is responsible for business logic and hence is the limelight of the project. The core auditor engine, config engine, security manager, business rules, report engine, object persistence, session control, error logging mechanism, and various other activities are performed by this layer. Predominantly this layer is written in C++ objects. For object design, the tool Rational Rose is being used.

The presentation interface acts as the interface between the business layer and the user interface. During the course of development and after the development phase, the product may be subjected to a lot of changes. In those situations it is better to handle it in parts, than all the layers. This layer takes care of those related issues. Basically, it is dominated with ATL objects

Finally, the user interfaces, which comprises of various screens and screen validation rules, with mandatory user level checking and other validations at screen levels. Basically, visual basic forms are there to suffice this job. If someone wants to change the screens, or some screen validations they can very much do it with less interference from other layers.

In the design and development phase, highly standardized documents were made and planned for the product to maintain the product's maintainability, enhancement and flexibility.