The term “expert system” could be applied to any computer program which is able to draw conclusions and make decisions, based on knowledge, represented as a database, it has. An expert system doesn’t have to be a replacement for a human expert. Such systems are often used as a support when a human can not collect all vital information due to theirs amount or complexity. That is why there is a need for systems that work in real-time and perform theirs functions faster and better then a human is able to do. There is also another reason, computer programs are much more cheaper then human experts (not in terms of their value, which may not be compared, but maintenance: costs of educations, salaries etc.).
Stages in the Development of an Expert System:
The essential principles:
get a prototype – a small, preliminary version of the final system – up & running at an early stage;
present this to the domain expert, for criticism;
proceed to refine this prototype with repeated debugging & knowledge accretion stages;
Continue with this cycle until the knowledgebase is finished.
Expert System Development Life Cycle:
Problem Identification Phase:
Identifying the problem and opportunity where the organization can obtain benefits from expert system, and establishing the Expert system general goals.
Feasibility Study Phase:
Assessing the feasibility of the expert system development in terms of its technical operational and economical feasibility.
Project Planning Phase:
Planning for the expert system project, including development team members, working environment, project schedule, and budget.
Knowledge Acquisition Phase:
Extracting domain knowledge from domain experts and determining the system’s requirements.
Knowledge Representation Phase:
Representing key concepts from domain and inter relationships between these concepts using formal representation methods.
Knowledge Implementation Phase:
Coding the formalized knowledge in to a working prototype.
Verification and Validation:
Verifying and validating working prototype against the system requirements, and revising it necessary according to domain expert’s feedback.
Installation and Training:
Installing the final prototype in an operating environment, training the users and developing documentation and user manual.
Operation/ Evolution / Maintenance:
Running the system in an operating environment, evaluating its performance and benefits and maintaining system.