Redirect scheme

NTUH HIS is a newly developed system (Hsieh et al., 2007; Ko et al., 2006; Yang et al., 2006).

It supports multiple execution environments, i.e., developing, testing, as well as on-line

production. Every environment is a complete HIS framework. For example, it includes

Portal Server, Auth-WS (Web-session Server & Win-session Server), WebUI Server and

34 Web Intelligence and Intelligent Agents

State-session Server (i.e., Application Server), Sub-system, as well as Database Server

(shown in Figure 2). The servers are configured in clusters as described in the “Overall

architecture” Section. However, in each environment, the numbers of the identical servers

are varied in clusters. To ensure practitioners as well as patients privacies, the databases in

developing and testing environments are scrambled.

In the developing environment, initially the HIS engineers implement modules,

functionalities locally and individually. Afterwards, the integrated modules are verified

through regression tests. Secondly, the software installs and deploys under the testing

environment for fully evaluations. At last, the products, including Legacy HIS and

Outsourcing Systems, are executed and running under the real, on-line environment for

daily activities. Switching among different environments is implemented via the usage of

Windows registry mechanism. Therefore, the portal can correctly redirect to developing,

testing, or on-line production servers spontaneously.

Single sign on service