Web - Based GIS: Front ends for enterprise

Implementation
Design, development and deployment are the key phases in a Web GIS implementation. The design of a graphical front end that will satisfy user requirements necessitates adequate requirements determination. Design of the DDAMs and their associated business rules needs to be coordinated with the design of the graphical front end. The DDAMs work within the graphical front end and access data according to the business processes developed in the requirements definition.

The design of a graphical front-end of a container application consists of providing versatility, expandability, and functionality. Versatility is the ability to utilize DDAM from different corporate-wide systems. The container application needs to handle messages from each DDAM, modify its user interface to accommodate each DDAM, and respond to each DDAM event. Expandability is the container application’s ability to model business rules and incorporate them into the user interface. Functionality is generated by examining the detailed requirements of all DDAM and incorporating them into the finished system.

DDAMs are designed to have configurable business rules and a graphical interface. These business rules describe how the DDAM interacts with other DDAMs. A portion of the container application consists of handling the interaction of DDAMs. The graphical interface consists of text or graphic display depending on the specifications of the DDAM.

The most generic and adaptable solution is to create a container application in Visual Basic as an ActiveX control. This container application is then embedded within an HTML page and then deployed on the Web. There are commercially available ActiveX controls that have MS Access-like interfaces, Figure 2. Using one of these controls accelerates the development process and provides a high-quality user interface. The different container applications within this interface are composed of DDAMs. The DDAMs are reusable so that multiple container applications can use the same DDAM and associated business rules.

Figure 2. Web GIS container application. The application consists of a data section, menubar, and toolbar. The toolbar contains icons of different container applications. The output of the selected container application is the data section. By selecting different container applications, the user accesses data for different tasks.

The container application and DDAM system is flexible enough to allow configures to create powerful and complex applications. Once each DDAM is designed, developed, and tested, it can be incorporated into container applications. Changes to the DDAM, bug fixes, or enhancements are distributed automatically using the ActiveX distribution framework. Modularity of the system is one of its major advantages. Discrete modules can easily be combined to create more complex applications. The inputs and output of each DDAM are specified by parameters, but the internals can change. DDAMs communicate with other DDAMs through messages handled by the container application. Figure 3. The actual details of how DDAMs are written and work is left up to the developer.

Figure 3. Interaction of GIS DDA Mand customer care DDAM. The GIS DDAM sends messages A , B, and C. The container application responds to message A. The customer care DDAM responds to message B. Message C has no receivers.

An Internet deployment scheme leverages the features of DDAM ActiveX lineage . Each DDAM is digitally-signed and assigned a version number. When a new version of the DDAM is available, it is automatically downloaded and installed on the client machine.

This simplifies software installation and upkeep. A user simply has to point to the correct location and open an HTML page in MS Internet Explorer or Netscape Navigator. All details of the software installation are handled by the ActiveX protocol. The building block nature allows quite complex applications to be built using DDAMs from different organizational systems.

Advantages of DDAM Technology
The advantages of implementing a Web container application composed of DDAMs include providing data across traditional hierarchical and departmental boundaries and reducing training through a consistent graphical front end. Departmental boundaries are boundaries based on the type of work each group is tasked to accomplish. Hierarchical boundaries are organizational boundaries defined by tasks required within a department.

Benefits of providing data across departmental boundaries include facilitating interdepartmental communication, applying better costing to operations, improving provisioning timing, providing geographic billing history, and comprehensive marketing analysis. Inter-departmental communication is enhanced because users in each department have access to data from other departments and a better understanding of the work done by all departments. Better costing results from incorporating information from accounting, inventory, and billing into design and engineering plans. Improved provisioning timing is a direct result of presenting marketing and sales with up to data capacities and potential capacities. In addition, customer care has more information about timing of network builds, service interruptions, and scheduled outages. Geographic billing history is the integration of the AM/FM data with billing history. Geographic marketing analysis is better defined by combining information from GIS, engineering, billing, and network operations.

Benefits of crossing hierarchical boundaries include greater independence at the user level, streamlining of business processes, and generating rule sets. Independence at the user level stems from access to better and more current information. This results in less managerial interaction. Better information presented to users allows them to make quicker decisions, streamlining the pertinent business processes. Configurable rulesets built into DDAM allow flexibility in changing parameters of different processes without additional software development.

A graphical front end results in a decrease in training time, an intuitive graphical user interface, and ease of customization. An application deployed on the Web requires little training as compared to multiple enterprise-wide applications. A user using a Webbased application has only to get acquainted with one user interface instead of the separate user intetface for each enterprise-wide system. This cuts the required training significantly and allows users to be productive more quickly. Intuitive graphical user interfaces are paramount for getting users to actually utilize a system. A system may have great features and provide significant improvements to a company’s business processes, but if users are unwilling to use it, benefits will not be realized. The plug-andplay aspect of the DDAM framework greatly eases customization. Configuration of container applications can satisfy changing business requirements.