Analysis Principle: Partitioning
Problem is partitioned - divide into parts that can be easily understood an established interfaces between the parts.
Form the fourth operational analysis principles suggests that the Information, Functional and Behavioral domains of the software can be partitioned.
Partitioning decomposes a problem into its constituent parts.
Conceptually, establish a hierarchical representation of function or information and then partition the uppermost element by :
• 1) Exposing increasing detail by moving vertically in the Hierarchical.
• 2) functionally decomposing the problem by moving horizontally in the hierarchy.
Example: Safe home security system.
Home security system software enables the home owners to configure the security when it is installed, monitors all sensors connected to the security system and interact with the
homeowner through a keypad and function keys and contained in the SafeHome control panel.
During installation, the SafeHome control panel is used to ' program ' and configure the system.
Each Sensor is assigned a number and type, a master password is programmed for arming and disarming the system, and telephone number are input for dialing when a sensor event occurs.
How SafeHome Works?
When sensor event is recognized, the software invokes an audible alarm attached to the system. After a delay time that is specified by the home owner during system configuration activities
The software dials a telephone number of a monitoring service, provide information about location, reporting the nature of the event that has been detected.
The telephone number is dialed every 20 seconds until telephone connection is obtained.
• All interaction with SafeHome is managed by a user-interaction subsystem that reads input provided through the keypad and function keys, displays prompting messages on the LCD display, displays system status information on the LCD display.