|
Since no such rules exist, the system must obtain
the data from the user or an external source such as a database.
This is a more reasonable question to ask a user, particularly if
they have access to a sales database and can check the sales volume.
In practice, an expert system would automatically determine this
answer by interfacing directly to an external databases
Goal List:
1. Determine if the purchases are over $250,000
2. Determine if the customer is a Priority customer
3. Determine if the response should be within 4 hours |
If the request for sales volume returns the customer's
purchases are $20,000, this determines the variable value, the top-level
goal on purchase amount is now satisfied, and it drops off the Goal
List. It does not matter that the rule that put the goal on the list
is false; the system is only working on the top-level goal.
The next Goal in the list, "Priority Customer" again
becomes the Top Level Goal and the associated rule again becomes the
rule to be tested.
Goal List:
1. Determine if the purchases are over $250,000
2. Determine if the customer is a Priority customer
3. Determine if the response should be within 4 hours |
IF
The customer purchases are over $250,000 per year
THEN
The customer should receive priority service
|
|
Based on the value of the customer's purchases,
which
is $20,000, the rule is determined to be false, so it will not fire
or indicate anything about the Top-Level Goal variable. This rule
is of no value in achieving the top-level goal.
However, there is another rule in the system that
also
provides information on the top level Goal variable:
IF
The customer works for a Partner company
THEN
The customer should receive priority service
The variable used in the IF part of that
rule becomes the new Top-Level Goal.
Goal List:
1. Determine if customer is from a Partner company
2. Determine if the customer is a Priority customer
3. Determine if the response should be within 4 hours |
There are no other rules that allow the engine to derive
"Partner Company", so it asks the user if the customer works
for a Partner company. This is a reasonable question to ask since
the number of partner companies is probably reasonably small.
In this example, assume that the customer is not from a
Partner company, so it drops that top Goal. After the Partner company
rule, the next rule to test is:
IF
The customer's company has significant growth potential
THEN
The customer should receive priority service
|
