--- title: "Expert system development steps" subject: "Artificial Intelligence" chapter: 7 key: "semester_6/artificial_intelligence:expert-system-development-steps" source: https://www.bctengineer.com/q/semester_6/artificial_intelligence/expert-system-development-steps site: BCT Engineering --- # Expert system development steps Artificial Intelligence · Chapter 7: Application of AI - Asked in: 2069 Bhadra, 8 marks; 2070 Bhadra, 4+4 marks; 2073 Bhadra, 2+6 marks (asked 3 times) - Video: [Expert System Life Cycle | AI | Stages of Development | Artificial Intelligence - Kanika Vats](https://www.youtube.com/watch?v=9CGpoOQSU5w) — Kanika Vats - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_6/artificial_intelligence/expert-system-development-steps - Whole chapter: https://www.bctengineer.com/md/semester_6/artificial_intelligence/chapter-7 ## Question What is an expert system? Explain the different steps (stages) of expert system development with an example. ## Short answer Expert system development steps: problem identification, feasibility, knowledge acquisition, representation, design/build prototype, testing/validation, implementation, maintenance. Example: car fault diagnosis with rules from mechanics. ## Answer An **expert system** is a program that captures the knowledge of human experts in a specific domain and uses it to give expert-level advice or solutions (e.g. MYCIN for diagnosing blood infections). #### Stages of development ```text 1 Problem identification v 2 Feasibility study / requirements v 3 Knowledge acquisition <------------+ v | 4 Knowledge representation | refine v | 5 Select tool / design and build -> 6 Testing and validation v 7 Implementation / deployment v 8 Maintenance ``` 1. **Problem identification:** decide whether an expert system suits the problem (needs a narrow domain, a scarce expert, rules and heuristics, and a clear benefit). 2. **Feasibility and requirements:** study cost, benefit, available experts, hardware and users; set goals. 3. **Knowledge acquisition:** the knowledge engineer collects knowledge from experts by interviews, observation and documents. 4. **Knowledge representation:** encode the knowledge as rules, frames or semantic nets, and choose a reasoning strategy (forward or backward chaining). 5. **Design and development:** choose a shell (e.g. CLIPS, Prolog) or language; build the knowledge base, inference engine, interface and explanation facility; build a prototype. 6. **Testing and validation:** run test cases and compare with the expert's decisions; correct rules; repeat steps 3-6 (incremental refinement). 7. **Implementation:** install, train users and integrate with existing systems. 8. **Maintenance:** update the rules as the domain changes. #### Example: car fault diagnosis - Problem: car does not start; experts (mechanics) are few. - Knowledge acquisition: interview a mechanic and obtain rules. - Representation: IF battery_voltage is low THEN fault = flat_battery. IF engine_cranks AND no_spark THEN fault = ignition. - Build with a shell; the system asks the user questions (does the engine crank?). - Test with 50 past cases; fix wrong rules; deploy in the workshop; add new models later. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. When is an expert system suitable for a problem? A. Wide domain, many cheap experts, no rules B. Narrow domain, scarce expert, rules and heuristics, and a clear benefit C. Any problem that needs a database D. Only problems with exact mathematical solutions Answer: B. Expert systems fit narrow domains where the expert is scarce, knowledge can be expressed as rules and the benefit is clear. (Key point: Problem identification) 2. What is the difference between knowledge acquisition and knowledge representation stages? A. Acquisition encodes rules; representation interviews experts B. Acquisition tests the system; representation deploys it C. They are the same step D. Acquisition collects knowledge from experts; representation encodes it as rules, frames or nets Answer: D. The knowledge engineer first gathers knowledge (interviews, observation, documents), then encodes it in a form such as IF-THEN rules. (Key point: Knowledge acquisition vs representation) 3. What happens when testing against the expert's decisions shows wrong results? A. The system is deployed anyway B. Rules are corrected and steps 3-6 are repeated (incremental refinement) C. The project is stopped permanently D. Only the user interface is redesigned Answer: B. Testing compares outputs with the expert, and wrong rules are corrected in an iterative refinement loop. (Key point: Testing and refinement loop) 4. Why is the maintenance stage needed? A. To train the knowledge engineer B. To select the shell C. To update the rules as the domain changes D. To identify the problem Answer: C. Domain knowledge changes over time, so the rule base must be updated after deployment. (Key point: Maintenance) ## Related in Artificial Intelligence - [Expert system architecture](https://www.bctengineer.com/question.md?key=semester_6%2Fartificial_intelligence%3Aexpert-system-architecture) — Artificial Intelligence, chapter 7, asked 6× - [Knowledge acquisition in expert system](https://www.bctengineer.com/question.md?key=semester_6%2Fartificial_intelligence%3Aknowledge-acquisition-es-architecture) — Artificial Intelligence, chapter 7, asked 2× - [Expert system pros and cons](https://www.bctengineer.com/question.md?key=semester_6%2Fartificial_intelligence%3Aexpert-system-advantages-disadvantages) — Artificial Intelligence, chapter 7 ## Related in other subjects - [Stages of hydropower development cycle](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Adev-cycle-stages) — Hydropower Engineering, chapter 2 - [Development stages and PRoR working principle](https://www.bctengineer.com/question.md?key=semester_7%2Fhydropower_engineering%3Astages-pror-working-arrangement) — Hydropower Engineering, chapter 2 - [Activities in OO system development](https://www.bctengineer.com/question.md?key=semester_6%2Fobject_oriented_analysis_and_design%3Aactivities-oo-system-development) — Object Oriented Analysis and Design, chapter 1 - [Water supply system and historical development](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Aws-historical-development) — Water Supply Engineering, chapter 1