1. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Lecture 2 Development Life Cycle of ES

2. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Life Cycle Life Cycle of a Classical Software Development Requirement Analysis DesignImplement Test / Maintenance

3. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Problems Traditional Life Cycle model is Linear Every Step can be completed before the next starts Requires exact understanding of the problem at the start of the project Ability to trace back to the original requirements

4. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Expert System Life Cycle Basic Principle: Iteration are inevitable Why? No body understands the problem exactly The problem becomes severe when the system under consideration is Knowledge based

5. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department ES Development Life Cycle Problem Selection Prototype Construction Formalisation Implement Evaluation Long-Term Evolution

6. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Unique Characteristics Customer is involved through out the process Frequent Demonstrations are encouraged Change is viewed as healthy

7. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Details: Problem Selection Problem Survey Candidate Selection Candidate Analysis Domain Applicability Expert Availability Problem Scope Cost/benefit Analysis Final Candidate Selection Task Characteristics (defining the nature of the ES)

8. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Details: Problem Selection Candidate Selection Does the task require expert knowledge? How much benefit the system will be to the organisation.? Is the solution valuable for long time to the organisation.?

9. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Problem Selection: Example Black Board Architecture Used for problems when knowledge acquisition is done from different sources Rule and Control Scheme Used under conditions when exact rules can be defined for a problem. The scope of application is also limited

10. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Problem Selection: Example An expert System has to be developed for incorporating knowledge from a manufacturing plant. The knowledge from various shops have to be collected into a control unit, that would indicate the time delays of the complete assembly plant. The system should also indicate the remedies for reducing the time delays in the each shop of the plant such as paint shop, heat treatment shop etc. The system to be equipped with on-line modification facility for each shop. TASK CHARACTERISTRICS !!!!!!!

11. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Problem Selection: Solution Black Board Diverse Source of knowledge from each shop Cooperating Knowledge sources Rule and Control For each Shop With Modification Facilities such as knowledge base editor

12. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Prototype Construction What should be the primary aim of Prototyping? To learn more about the domain To gain deeper understanding of the nature of the project To demonstrate overall systems functionalities To test the initial design

13. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Prototype Construction Should the prototype be kept for detailed design? Keep only those parts of the prototype whose level of implementation quality is similar to that expected of the final system If it has to be discarded that should only be done after guidelines are for new implementation are extracted from the experience

14. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Formalisation Formalisation is the development proces Record key understandings from the prototyping phase Plan the implementation Provide visibility at each level Draw implementation plans Revisit pre formalisation steps to improve When formalisation is inevitable?. For large scale systems the formalisation step becomes very important

15. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Formalisation: Steps

16. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Implementation Plans Prototype revisited System framework development Core knowledge Acquisition Coding Internal Integration Internal verification Revision of inference engine and representation methods Establishing and revising knowledge base partitioning Further verification

17. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Core Knowledge Development

18. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Evaluation Gradual degradation Vs Sudden Collapse Task difficulty Adequacy

19. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Complete Example Want to develop an expert system for detecting fire and suggesting remedial action Gather Initial Data Fire occurs when the room temperature is high and smoke appears Temperature can be measured using Temperature gauge Smoke can be indicated using smoke detector Remedial action could be to assert that fire is on and then to call the fire brigade/or switch on the sprinklers

20. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Complete Example Carry Out Task Characteristics What should be the architecture of the knowledge representation?. Black Board or Rule control based Rule Based Control Represent knowledge in appropriate manner Tree format Extract rules from the tree

21. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Tree Format Switch on the sprinklers Fire hot smoky Alarm beeps

22. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Rules IF alarm beeps THEN smoky IF hot AND smoky THEN fire IF fire THEN switch on the sprinklers Which rule should be fired?. Depends on the state of the initial database of facts

23. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Rules Based System Need to assert the initial facts in a database and then to change them after each rule is fired Control Scheme Database of facts alarm beeps hot Rules IF alarm beeps THEN ADD smoky IF hot AND smoky THEN ADD fire IF fire THEN ADD switch on the sprinklers

24. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Rules – Representation Using CLIPS IF temperature(R,hot) AND environment(R,smoky) THEN fire-in(R) (defrule fire-alarm (temperature ?r1 hot) (environment ?r1 smoky) (assert (fire-in ?r1)))

25. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Problem A problem faced by an organisation is to select candidates from among a very large pool of individuals for appointment to advanced training. Since the cost incurred for such training is considerable it is deemed important to carry out this process in a logical, efficient manner. The selection is done in two phases. First a test is conducted followed by the second phase of physical examination and evaluation. People who perform good go straight to the second phase. After the 2 nd phase the Outstanding candidates are approved while poor are reject and average are placed on the waiting list. The marginal candidates after the first phase are examined on the bases of their job performance. Good performers in this test are allowed for the second phase and rest are rejected.

26. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Decision Tree

27. Lahore University of Management Sciences, Lahore, Pakistan Dr. M.M. Awais- Computer Science Department Rule Extraction