In order to determine the scope of the land records system, Chester County conducted a series of interviews and questionnaires. The information was analyzed to identify the functions performed by each department. Each function is a responsibility and process of procedures being performed by an organization to carry out its mission. A set of hardware, software, and database components was identified to support the functions. The system components were matched with the required functions to develop a series of applications that provide the information and processing capabilities needed by the County. The various system components were integrated into a conceptual design that will operate effectively in the County based on client/server and open architecture design philosophy. Figure 2 shows the conceptual design of the land records system.
CHESCO-LRS uses powerful geographic information and database management systems at its core to capture, store, manage, retrieve, process, report, and display land related information. There are three major components in its core: Tabular Database Management system (TDBMS - Oracle), Spatial Database Management System (SDBMS - ArcStorm), and Image Database Management System (IDBMS - Imaging Documents System). These three DBMSs are sometimes referred to as TSI systems. Around these core components is a series of applications that interact with the data and management functions to provide specific query, display, and analysis capabilities for various County departments. CHESCO-LRS will be automated to provide the necessary speed and capabilities to satisfy user requirements effectively through casual user and public access interfaces.
Around the tabular, spatial, and imaging database management systems are applications that allow the various users to gain access to the databases and to perform functions they require. These functional applications can be developed using script languages within management systems or using fourth generation development languages such as C, COBOL, or FORTRAN.
The applications provide windows between users and land record databases, and can be divided conceptually into three kinds: function specific, general support, and public access interface. The function specific applications use predefined standard procedures to perform routine information processing functions, including specific inquires and production operations such as calculation of appraised values. The general support applications are to facilitate access, inquiries, retrieval, processing, reporting, geographic analysis, and map production on an adhoc basis. This is often referred to as a casual user interface (CUI), and it is primarily for internal users. The public access applications use web technology and the Internet to develop user interface and provide the public with the ability to query, display, and generate maps from a subset of the land records database.
Each application may use its tailored menus, forms, screens, prompts, and dialogs to facilitate the use of the TSI systems. The applications may contain various processing procedures to tabulate, aggregate, and analyze data by various functional organizations, but all of them use standard database access procedures to enter and retrieve data and adopt the similar security system. The central databases can be accessed through these applications from a graphic workstation, a PC, or a dummy terminal across the network and the Internet.
In addition to the above applications, CHESCO-LRS provides capabilities for maintaining the integrity of the database and interfaces for casual and public access. The maintenance capability includes editing procedures, audit trails, backup, and security for all software and data. They need to be developed or be embedded in application procedures. The TSI systems, applications, and interfaces in CHESCO-LRS can be viewed as the software component in an abstracted land records system (Tu and Massucci, 1997).
One of the important applications is the Parcel Update Application. The Parcel Update Application is designed for the Bureau of Land Record to update and maintain the database. It consists of ArcInfo AML applications and Oracle Forms. CHESCOView is designed to provide internal access to the database. It is an ArcView application. CHESCOGateway is intended to provide web-based interface for public access to the database.
