Function Point Analysis

1. Function Point Analysis example

2. Function point • FP is defined as one end-user business function • FPA evaluates the system from a user perspective

3. Function point • 5 groups of FP • Outputs • Inquiries • Inputs • Files • interfaces

4. FP Calculations • There is no universally acceptable standard to calculate FP. Therefore, different groups, or companies have their approach to making the calculation. • Some approaches are more straight forward than others. • The most important things to remember are: • to choose an approach and use it consistently. • Collect data (estimate and actual) on all projects with the intent of improving project estimates • We will use a simple approach to make the calculations

5. Outputs • Outputs are items of business info that is processed by the computer • E.g., a report printed or otherwise

6. Output Examples • Transaction flies send to another application • Customer invoices • Accounts payable checks • Punch cards • User screen message • Tape transaction • Backup file • Floppy disk transactions • Etc.

7. Inquiries • Inquiries are when you ask a question that requires the use of a database, and these conditions are true • solicit an immediate response, • use simple keys, and • perform no update function • E.g., looking up a customer info • E.g., Requesting info on a customer account • Inquiries have an input part and an output part. Consider each separately.

8. Inquiries example • Suppose I want to find out about AA flight #73, this is an inquiry because it is a simple key, response immediate, and no update takes place. • If we wanted to find out about all flights leaving Chicago between 9-11 am for New York, this would not be an inquiry because the key is no longer simple even though the other two conditions are true.

9. Inputs • Inputs are unique if: • It has a different format, or • It has the same format as another input but requires different processing logic • Suppose we had two input screens, each with the same format but different processing logic. We count each screen as a separate input. • If the same two screens had identical processing logic, only one would be counted as an input. • Suppose we have a screen whose function is to update a file. Since each of the three update functions (delete, change, add) requires different processing logic, we would have three update functions, not just one.

10. Files • Only stores that hold permanent data are considered logical files. • Each logical view is considered a separate file. • E.g., suppose we have a master customer file. One door (i.e., key) to the file is the cust # and another door is the customer name. In this situation, we have two logical files. • Also each logical user view into a database is considered a separate file. • Suppose a database employs 5 different logical views for 26 users. We would count 5 logical files.

11. Interfaces • Interfaces are data, files, or control information within the application boundary that is sent to, shared with, or received from another application. • Files shared between applications are counted as both files and interfaces within each application if they are used in both. Otherwise, file credit is given only to the application using, maintaining or doing the work on the file. The other application would receive no file credit but will receive interface credit.

12. Interfaces Example • Data or control info is passed from file A to file B. A receives credit for file and interface. B receives interface credit only. • Data or control info is passed from file B to file A. B receives credit for file and interface. A receives interface credit only. • Data or control info is shared between file A and file B. A and B would each receive both file and interface credit.

13. Function point • Each business function is classified and weighted by its level of complexity being • Simple (low) • Average (med) • Complex (high)

14. TABLES

15. TABLES

16. TABLES

17. Calculation • See pg 62- 65 for formulas