Software Development Strategies (Part two)

FUNCTION METHOD POINT (5th September, 2016)

Is probably the most popular method to estimate the size of commercial software applications.

• There are five functions that occur frequently in software development and categorized them according to their relative development complexities:
• Input (from users) like direct manipulation
• Output(to users) like feedback, system status.
• Inquiries: Interactive inputs that require an answer from the system.
• Data file: Any persistent entity handled by the system.
• Interface: Any Interface with other systems.

• These elements are classified accordingly to the complexity (simple, middle or complex) then we need a standard value to each element.

*Example of elements classified by complexity.

*Example of a Safe Home System.

• CORRECTION FACTOR: It is needed for evaluate technical complexity.

For the Correction factor there is some Technical Complexity, we wll put a table to know how to evaluate properly technical complexities, it's called "The Multiple Sites Factor Explained"

Score As	Descriptions to determine Degree of influence
0	User requirements do not require considering the need of more than one user/installation site.
1	Needs of multiple sites were considered in the design and the application is designed to operate only under identical hardware and software environment
2	Needs of multiple sites considered in the design, and the application is designed to operate only under similar hardware and/or software environments
3	Needs of multiple sites were considered in the design, and the application is designed to operate under different hardware and/or software environments
4	Documentation and support plan are provided and tested to support the application at multiple sites and the application is as described by 1 or 2
5	Documentation and support plan are provided and tested to support the application at multiple sites and the application is as described by 3

• Technical Complexity Adjustment:

Where Fi(i=1 to 14) correspond to the value assigned to each complexity factor:

• Last Step. Once calculated the adjusted Function Points we estimate the size of the system to be developed in term of lines of code(LOC) by using the formula:

LOC = FP * LOC AveragePerFunctionPoint

• Effort/Estimation

Effort = FP / AverageProductivityFP

FOR EXAMPLE:

Effort = 62/12 = 5.2 personXmonth

• Considering a monthly salary of 15,000
• A person produces an average of 12 FP
• Cost per function point is 1,250 pesos
• Cost = FP*CostPerFunctionPoint

Cost = 62*1250 = 77,500