This chapter discusses the steps of building a knowledge based system (KBS) using the rule-based system discussed in Chapter 3. As an example of the problem, the case of the Health Maintenance Organization (HMO) will be taken.
HMO is an organization that provides health services to its members, such as medical services, ambulance services, etc. Each member has paid all costs in advance. To ensure that serious health problems will receive priority service, a manager has assigned someone to conduct initial screening of patients. Screening is done by consulting with the Expert System to determine the status and type of service appropriate for the patient.
Steps to Build KBS
STEP 1: Isolate the area for KBS
To limit the problems in the expert system to be built, organizational limitations and services that can be provided by the system must be given. For example, for the HMO system, the limitations of the organizational structure and services are shown in Figure 4.1.
Figure 4.1 Block diagram of HMO organization and services
STEP 2: Decision Target
After the problem is limited, the next step is to determine the decision target for the expert system. Patients generally need help for new cases or ongoing treatment for long-standing diseases (follow-up cases). Or maybe other patients only need information or other services, while those who are not members will be directed to participate in this HMO membership. Therefore, 3 things can be determined as the main factors that determine the decision target (See Figure 4.2), namely:
- HMO status: What is the membership status of the patient? The membership declaration of the patient will be followed by validation of the id number.
- Reason: What is the reason for coming to the HMO? Is it a new case, followup case, information seeking or other visit?
- Problem: How serious is the patient's current condition? In this case it can be identified from the temperature and other symptoms.
Figure 4.2: Block diagram of HMO decision target
STEP 3: Create a Dependency Diagram
Dependency Diagram is created as shown in Figure 4.3.
STEP 4: Creating a Decision Table
The decision table is derived from the dependency diagram in Figure 4.3. Since there are three triangles in the figure, there will be 3 decision tables. The decision table for Set 1 (Rule 1-5) is as follows:
Figure 4.3 Dependency diagram of HMO
Decision Table Set 1
Simplification of Decision Table Set 1
STEP 5: Writing IF-THEN Rule
Next, based on the reduced decision table, a rule-based system can be derived as shown below:
Writing IF-THEN Rule
EXERCISE Based on the example above, create a decision table and IF-THEN rule for Set 2 and Set 3!
EXERCISE
After graduating from high school, Julaikah has a desire to continue her studies at a higher education in the field of computers. However, because the field of computers has several disciplines, Julaikah must consult an expert system to determine the right choice for her. Create an expert system to help Julaikah determine her choice with the following criteria:
Recommended disciplines include: Computer Programmer, Computer Science, Computer Technician or other fields other than computers.
The three main things that determine decisions are:
- Aptitute Test (ok, not-ok) which includes: math ability test (Yes, No) and programming ability test (Yes, No).
- Interest Test (Good, medium, low) which includes: interest in computers (Yes, No), interest in repair skills (Yes, No) and interest in problem solving (Yes, No).
- Financial capability (Yes, No).
So based on the criteria above, determine the rules using a rule-based system, with the following (recommended) process sequence:
- Define Dependency Diagram for the above case
- Determine the Decision Table for the above case
- Determine the rules to solve the above case.