Expert System and Decision Support System

In this article, we will discuss what is Expert System (ES), what is Decision Support System (DSS), how they work, and what is the difference between them. The examples presented here will be an environment planning cases.

Expert System (ES)

• ES is based on simple rule-based logic
• Problem is completely defines
• There is clear way for the solution method
• ES represent precisely what is needed, the extraction of the expertise from those who know and making that knowledge available to those who don’t know, with very positive additional connotations of top-down technology transfer within organizations.
• Example: locating critical areas for non-point leakage of nitrogen and phosphorus. The principle is to use GIS and expert systems to integrate landscape concept which consider hydrological and hydrochemical processes into account.

Decision Support System (DSS)

• The problem is open-ended
• The evaluation required to solve it is also incompletely defined/ill-defined problems. Its characteristics: the solution involving a mixture of methods and dependent on the perspective of the user
• One way of method: Multi Criteria Evaluation in IDRISI Andes software
• DSS has flexibility in the form of choices of data, procedures, and displays
• Example: Use MCE in ADRISI Andes to determine the best site location for ecovillage

Comparison of ES and DSS

	ES	DSS
Objectives	To replicate humans	To assist human
Who decided	The system	The user
Orientation	Expertise transfer	Decision-making
Query	Machine queries human	Human queries machine
Client	Individual user	Possible group user
Problem area	Narrow	Complex, wide

Conceptual framework of DSS

• A set of data sources
• A set of models and procedures (ES can be part of these)
• A set of display and report formats
• A set of control mechanisms to navigate between the other three

Summarized from:

• Expert systems and decision support. Chapter 2 in: ES and GIS for Impact Assessment. By Rodriguez-Bachiller, A. & Glasson, 1. 2004