System Function Identification and Specification

Questions and Answers

Functionality must be evaluated in an operational context.

Functions can be described using business process models and use cases.

Viewing functions on different levels allows for a comprehensive understanding of system requirements.

A business process model is a visual representation of the processes that a business undertakes. Signup and view all the answers

Use cases describe interactions between users and the system, outlining functional requirements. Signup and view all the answers

Function hierarchies represent a systematic arrangement of functions, showing their relationships. Signup and view all the answers

A behavioral model describes how a system behaves in response to different conditions or inputs. Signup and view all the answers

Usage context refers to the specific environment and conditions under which a system will be used. Signup and view all the answers

The component model outlines the individual components of a system and their interactions. Signup and view all the answers

Modes describe how a system operates under different conditions or scenarios. Signup and view all the answers

Study Notes

Identification of System Functions: Functions are derived through scenarios to outline system behavior.
Refinement and Interactions: Functions are refined and interactions among components are identified for clarity.
Interface Specification: Involves defining user interactions, such as entering user credentials and verifying accounts against a database.

Use Case: A collection of all potential scenarios for an actor aiming to fulfill a technical goal through the system.
Scenario: Represents a sequence of interactions between an actor and the system, detailing the actions taken.

Use Case: Comprised of multiple scenarios, providing a broader overview of functionality.
Scenario: Specifically an ordered interaction, focusing on functional requirements and can be broken down into smaller actions.
Outcome Variability: Scenarios can lead to either successful or unsuccessful results.

ATM Example: Various actions like transferring money, depositing, and paying out are illustrated as parts of the use case.
Purpose and Context: Use cases provide structured views that encompass multiple scenarios, highlighting the intent behind system behavior.

Function: A visible aspect of the system's behavior from the interface viewpoint, serving specific purposes.
Function Hierarchy: Analyzes and structures functions and sub-functions, mapping their dependencies and interactions.

System Behavior Overview: Helps in understanding and analyzing system functionalities.
Use Case Connection: Functions are identified and refined based on use cases, emphasizing their significance in requirements engineering.
Operational Context: Functionality needs to be contextualized within operational frameworks to ensure comprehensive understanding.

Business Process Models: Functions can be represented through various formats including business processes, use cases, scenarios, and function hierarchies.
Behavior Models: Such models outline how functions interact with system components and help in structuring system behavior.