The Use Case Model



USE CASE MODEL

Here are the use case models for our software project:

| | | |

| |Buyer qualification Use Case | |

| |Collect personal data | |

|Actor: business users |Perform calculations |Actor: customers |

| |Show buyer qualification | |

| |Print report | |

|Use Case name:      |Buyer Qualification |

|Definition: |Computes the maximum amount of purchasing power, given the income and debt of the borrower and the interest rate of the |

| |proposed loan. To do this the total monthly payment, including the principal and interest, property tax, hazard insurance |

| |and mortgage insurance (if required) are added to the borrowers existing consumer debt (lasting more than 6 months) and |

| |this total is then compared to the borrowers income. If the selling price is know that income to debt ratio is computed. |

|Notes: | |

| | | |

| |Cost comparison Use Case | |

| |Collect financial data | |

|Actor: business users |Perform calculations |Actor: customers |

| |Show cost comparison | |

| |Print report | |

|Use Case name: |Cost Comparisons |

|Definition: |Creates a side by side comparison of up to three loan programs. It is generally used by real estate agents during an open |

| |house sales presentation to gain buyer interest. Because the program only generates 10 pt. courier output it is generally |

| |printed over a letter head or some sort of attractive background to make it more appealing from a marketing stand point. |

|Notes: | |

| | | |

| |P.I.T.I. calc. Use Case | |

| |Collect financial data | |

|Actor: business users |Perform calculations |Actor: customers |

| |Show P.I.T.I. calculations | |

| |Print report | |

|Use Case name: |P.I.T.I. Calculations |

|Definition: |Computes the Principal Interest Tax and Insurance elements of the total monthly loan repayment schedule. Principal and |

| |interest are the monthly payment most people have in mind, but there are also the real estate taxes, hazard insurance and |

| |mortgage insurance (generally required if the down payment is less than 20% of the selling price) to be considered. The |

| |total payment P.I.T.I. is an important consideration in loan qualification. |

|Notes: | |

| | | |

| |Loan comparisons Use Case | |

| |Collect loan data | |

|Actor: business users |Perform calculations |Actor: customers |

| |Show comparison report | |

| |Print report | |

|Use Case name: |Loan Comparisons |

|Definition: |Gives the loan originator the ability to be a loan consultant. Using this program the LO can guide the borrower to the best|

| |loan option. It accomplishes this by calculating the actual cost of a loan over a given amount of time. The cost to |

| |originate the loan is added to the interest paid and compared to the loan balance at some time in the future to determine |

| |the lowest actual cost. For example a loan that cost 10% (10 points) to originate would cost more than one that cost only 2|

| |points, but what if the one that cost 10 points had an interest rate of 2% and the one that cost 2 points to originate had |

| |an interest rate of 10%. |

|Notes: | |

| | | |

| |Mortgage refinance Use Case | |

| |Collect loan data | |

|Actor: business users |Perform calculations |Actor: customers |

| |Show refinance report | |

| |Print report | |

|Use Case name: |Mortgage Refinance |

|Definition: |Compares the borrowers current loan to a proposed one. It computes the difference in payments and the difference in loan |

| |balances given a point in the future. It also computes the number of months necessary to regain the cost of originating the|

| |new loan. An old rule of thumb is don't refinance until the rate is at least 3% lower than the current loan. This program |

| |typically proves the foolishness of that rule of thumb. |

|Notes: | |

| | | |

| |Amortization schedule | |

| |Use Case | |

|Actor: business users |Collect financial data |Actor: customers |

| |Perform calculations | |

| |Show amortization info | |

| |Print report | |

|Use Case name: |Amortization Schedules |

|Definition: |This part of the program uses input from users to produce amortization schedules. |

|Notes: | |

| | | |

| |Fixed rate vs. ARM Use Case | |

| |Collect financial data | |

|Actor: business users |Perform calculations |Actor: customers |

| |Show report | |

| |Print report | |

|Use Case name: |Fixed Rate Loan vs ARM |

|Definition: |Compares a fixed rate mortgage to a adjustable rate mortgage. It produces a best and worst case scenario given the number |

| |of months a borrower intends to keep the mortgage. In general the ARM will win out if the retention period is short. Some |

| |types of adjustable rate financing (negative amortization allowed) can be desirable for some borrowers because they allow |

| |the borrower to keep the payments low by tacking the difference on to the loan balance (pay me now, pay me later). |

|Notes: | |

| | | |

| |Financial calculator Use Case | |

| |Collect five elements data | |

|Actor: business users |Perform calculations |Actor: customers |

| |Show report | |

| |Print report | |

|Use Case name: |Financial Calculator |

|Definition: |Computes the five elements (loan amount, monthly payment, loan term, interest rate and loan balance) of a simple financial |

| |calculator. It computes any one of the four elements (loan amount, payment, term, interest rate when only three of the |

| |elements are known. If I know the term, interest rate and loan amount what is the monthly payment? If I know the payment, |

| |term and loan amount what is the rate? It also computes the future loan balance when the four elements are given along with|

| |a future date (number of months the loan is in force). Therefore I can know how much I will owe in 60 months if I make all|

| |my payments on time for a given loan amount, rate, payment amount and loan term. |

|Notes: | |

| | | |

| |Closing cost estimate | |

| |Use Case | |

|Actor: business users |Collect financial data |Actor: customers |

| |Perform calculations | |

| |Show estimate report | |

| |Print report | |

|Use Case name: |Closing Cost Estimate |

|Definition: |Calculates the actual cost of obtaining the loan including all the various elements. It also computes the monthly PITI |

| |payment and as an option will compute the APR. |

|Notes: | |

| | | |

| |Seller’s net proceeds | |

| |Use Case | |

|Actor: business users |Collect financial data |Actor: customers |

| |Perform calculations | |

| |Show net proceeds report | |

| |Display schedule | |

| |Print reports | |

|Use Case name: |Seller’s Net Proceeds |

|Definition: |Calculates the cost to the seller for a sales transaction, including the closing costs associated with selling a home and |

| |the real estate commissions. It also includes an investment schedule should the seller opt to invest some of the proceeds.|

|Notes: | |

| | | |

| |Rent vs. Buy Use Case | |

| |Collect home data | |

|Actor: business users |Perform calculations |Actor: customers |

| |Show reports | |

| |Print reports | |

|Use Case name: |Rent vs Buy |

|Definition: |Compares the cost of renting to home ownership. All the elements are considered including the estimated appreciation of |

| |the property, the equity to be gained, over time, in the home and the tax advantages. |

|Notes: | |

| | | |

|Actor: business users |Saving user data Use Case |Actor: customers |

| |Store user info to the DB | |

|Use Case name: |Saving User Data |

|Definition: |Save user specific information into a database management system for later retrieval. |

|Notes: |Will be implemented on a case-by-case basis. |

| | | |

| |Retrieving user data Use Case | |

|Actor: business users |Choose a user |Actor: customers |

| |Retrieve info from the DB | |

|Use Case name: |Retrieving User Data |

|Definition: |Retrieves user specific data from the database management system for form generation. This data may be edited and saved |

| |back into the database management system. |

|Notes: | |

| | | |

| |Deleting user data Use Case | |

|Actor: business users |Choose a user |Actor: customers |

| |Delete their data | |

|Use Case name: |Deleting User Data |

|Definition: |Deletes old or inaccurate user accounts from the database management system. |

|Notes: | |

| | | |

|Actor: business users |Program variables Use Case |Actor: customers |

| |Change program settings | |

|Use Case name: |Program Variables |

|Definition: |All the assumptions and defaults made by the program are listed and can be changed by the program user. |

|Notes: | |

| | | |

| |Help system Use Case | |

|Actor: business users |Help using the program |Actor: customers |

| |Help setting up accounts | |

| |Loan descriptions | |

| |Menu item descriptions | |

|Use Case name: |Help system |

|Definition: |This is the part of the system that contains the help files, and is intended to help the user understand how the program |

| |operates and what it’s functions are. Perhaps the most important part of this system is the ability to find out more about |

| |what each of the reports mean. |

|Notes: | |

There are currently only a few actors in our system, because it's a standalone application (not connected to external actors such as web and database servers), and is targeting a specific group of users.

|Actor name: |Business users |

|Definition:            |People who could use the program to advise clients about their home-mortgaging possibilities |

|Notes: |Other business uses are possible. |

| | |

|Actor name: |Customers |

|Definition: |The people who are interested in mortgaging their home, and want to use the features of the program themselves.  |

|Notes: |Packaging this product along with some of the company's other products and allowing customers to run it on their |

| |own would add value, and the product could also be sold by itself. |

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