| Events and Facts |
Loan Application Decision |
Comments |
| Peter Johnson applied for $50K loan |
Rejected |
Insufficient Income. But a loan
officer noticed that they have a valuable client with the same
address |
| Joe & Dawn Johnson agreed to be Peter's
guarantors. They have a Housing Loan with Available Equity of
$300K and Remaining Debt of $150K |
Accepted |
$100K surplus is a sound proposition. But
conducting more detailed analysis, the officer noticed a joint
borrowing on Mt. Johnson's file which is not with his wife |
| Joe Johnson and his partner Bill Smith
(50/50) have a Business Loan for $200K with Available equity of
$52K |
Accepted |
The remaining $26K surplus still meets
requirements. But Bill and Susan Smith have other
facilities outstanding against their property as well as the
business loan |
| Bill & Susan Smith have a Housing Loan with
Available Equity of $240K and Remaining Debt of $150K |
Accepted |
Still a surplus. But a lending clerk noticed
a secured personal loan in the name of Tommy Smith for $50K
secured by his parents |
| Their son Tommy Smith has $50K loan secured
by his parents |
Rejected |
Accumulated remaining equity is less than the
requested loan amount. The initial
debt to Peter Johnson would be $8.8K short on cover |
Web-based GUI: Interaction Steps
The following screens represent different interaction steps for the
above scenario. They are created using OpenRules Web Forms.
Step 1. Entering Borrower Personal Data
After
validating SSN correctness, the button "Next" moves a dialog to the
next interaction step.
Step 2. Entering Loan Request Information
This
step validates the requested loan amount for min/max limits, and checks such
conditions as "Loan term cannot be more than 36 months for amount < $5,000".
Step 3. Entering Related Facts (securities that may
affect accept/reject decision)
Initially there could be no related facts/securities. By
clicking "Add Security", you can add new rows to this table and enter
the related information. Buttons "Del" allow to delete previously
entered securities. Securities have a flag "Active" allowing to include
or exclude them from the total loan evaluation process. The button
"Next" executes the rule engine "validateIncomeWithEquities" that
recalculates the total equity and total remaining debt using ALL related
securities and then it makes an Accept/Decline decision.
Step 4. Displaying Rule Engine Results with
Explanations
By
clicking "Prev", a user can go back and make changes in the loan amount or
related securities.
Implementation
Presentation Logic. Here is a list of four interaction steps and
rules that should be executed before displaying the proper screens:
All screens (interaction steps) above are defined as Layout tables in
Excel. Please note that before generating the Results view, we direct
system to execute business rules presented in the rules table "validateIncomeWithEquities". The interaction logic that specifies which processing steps
should be executed upon which events is presented in the following rules
table ("state machine"):
In particular, it defines that if a user clicks to the button "Next" on
the last screen "Results", it would be taken to the first screen "BorrowerData".
By clicking "Prev", a user always can go back to the "Securities" view
to add/remove related securities.
Here are the screen layouts themselves that can be easily associated
with their actual web views above.
Step
1
Here we are using a standard input validator "validateSSN" that will
generate an error message if the entered SSN does not have a valid
format.
Step
2
Here we are using two custom input validators:
1) "validateLoanAmount" that will generate an error message if the
entered Loan Amount violates min/max limits
2) "validateLoanTerm" that will generate an error message if Loan Term
is larger than 36 months while Loan Amount is less that $5,000. Here are
Excel tables, in which we defined these validators:
Step
3
This layout can be dynamically changed: a user can add/delete rows in
the table of securities. So, we will build this dynamic layout "on the
fly" using the method "securityTableContent":
This method takes a fixed layout "securityTableHeader"
and attaches (merges) to it all security rows known by that moment and
saved in the object SecurityList. Each row is formed based on the
following layout:
The buttons that allow a user to add or delete securities are defined in
the following methods:
Step
4
All these layouts in different moments (defined by the processing flow
rules above) play role of the current
layout if the following generic layout:
And finally, the main of the LoanDynamics application that will be
executed on every client-server interaction presented in this Excel
table:
Business Logic. Business rules used
in this application should evaluate borrower's income and debt with
respect to all related securities. We will use simple formulas
that calculate the total equity and total remaining
debt to makes an Accept/Reject decision. The proper rules and formulas
are presented in the following Excel tables:
Business Object Model. To
represent a business object model for this application we use 4 simple
Java classes:
|
Class Name |
Class Properties and Methods |
| Borrower (Java bean) |
String fullName;
String SSN;
double monthlyIncome;
double monthlyDebt; |
| LoanApplication (Java bean) |
Borrower borrower;
double loanAmount;
int loanTerm;
String purpose;
String status;
String comments; |
| Security (Java bean) |
String id;
String type;
String securedBy;
double equity;
double debt;
boolean active |
SecurityList
(inherited from java.util.ArrayList) |
Maintains a list of securities.
public double calculateTotalEquity()
{
double total = 0;
for(int i=0; i<getLength(); i++)
{
if (getSecurity(i).isActive())
total +=
getSecurity(i).getEquity();
}
return total;
}
public double calculateTotalDebt()
{
double total = 0;
for(int i=0; i<getLength(); i++)
{
if (getSecurity(i).isActive())
total += getSecurity(i).getDebt();
}
return total;
} |
