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UML IN A PRODUCTýS LIFE CYCLE

by Venu Kosuri

Start ý Basic Views ý The Whole Picture ý Use Case View ý Use Case Diagram ý Structural View ý Domain Modeling ý Class Diagram ý Behavioral View ý Sequence Diagram ý Collaboration Diagram ý FSM ý Scalability Limitations ý Lack of Support ý State Charts ý Activity Diagram ý Implementation View ý Environmental View ý Sources and PDF

USE CASE VIEW

In any product development, the first step is marketing. Marketing research results in commercial requirement specification (CRS) for a product. The next step is to gather functional requirement specifications (FRS), often called system requirements, of the product from CRS.

Use case view helps with gathering FRS. In this view, a system is modeled as a black box. Any real-time embedded system responds to a large number of external events that cause a system to do some desired activity. Each desired activity is nothing but a functional requirement. So, system requirements can be better understood by understanding the actors that generate external events and the work that must be carried out in response. These event-response pairs are called "use cases".

The two steps involved in use case analysis are to identify the actors and the use cases. An actor is anything that interacts with the system and, thus requires something from it. An actor can be like a human, machine, independent system, sensor, or so forth. For example, for an ATM, the insertion of a debit card is an action initiated by a human actor.

A use case describes anything the actors want the system to do. In an elevator control system, a person requests a lift to a particular floor, the motor control box requires the elevator to open the door when the elevator comes to a halt, and the door sensor detects an obstruction and prevents the door from closing.

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