software engineering lecture 2 aspi8-4 anders p. ravn, feb. 2004

Software Engineering

Lecture 2

ASPI8-4

Anders P. Ravn, Feb. 2004

Your Report - 2!1.1. Requirements SpecificationRequirements Specification

1.1 System Definition1.1 System Definition

1.2 Problem Domain Structure1.2 Problem Domain Structure

1.3 Application Domain Structure

1.3.1 Use Cases

1.3.2 Functions

1.3.3 Interfaces

1.4 Acceptance Test Specification

2. Architecture

2.1 Criteria

2.X Module Interfaces

2.T Integration Test Specification

Overview

• Software Requirements• OAD in Application Domain Analysis

Architecture for Embedded Systems

1. Usage

2. Functions

3. Interfaces

Activities: application domain analysis

Usage

Functions

Systemdefinition

and ProblemDomainmodels

Interfaces

ApplicationDomainModel

andSoftware

Requirements

Use Case

name

<<actor>>name

<<actor>>name

<<actor>>name

Activities: use case analysis

Find actors and use cases

Analyse work tasks

System definition Use cases

Evaluatesystematically

Structurethe usecases

Example: Start tool use

start_tracking

<<actor>>TractorOperator

<<actor>>RowWeeder

Each use case is described textually and/or by a behaviour diagram

Actor stereotype

start_tracking<<actor>>

RowWeeder

TractorOperator

Functions

The actions of actors in use cases:• Update – state change in (internal) model• Signal – event in (internal) model• Read – (internal) model state inspection• Compute – (internal) model state summary

Update/Read/

Compute

Signal

<<actor>>System

Interfaces

System

<<Interface>>Alarm

IPanelUpdate/Read/Compute

Signal

Example: User Interface

Example: Camera Interface

The camera delivers JPEG compressed images with a frame rate of up to 10 per second.

The resolution is ...

The hardware interface is a DMA ...

The standard software driver is ...

Summary: Application Domain Analysis

• Use Cases

• Functions

• Interfaces

Your Report - 3!1.1. Requirements SpecificationRequirements Specification

1.1 System Definition1.1 System Definition

1.2 Problem Domain Structure1.2 Problem Domain Structure

1.3 Application Domain Structure

1.3.1 Use Cases

1.3.2 Functions

1.3.3 Interfaces

1.4 Acceptance Test Specification

2. Architecture

2.1 Criteria

2.X Module Interfaces

2.T Integration Test Specification

Design criteria

• Usable• Secure• Efficient• Correct• Reliable• Maintainable• Testable• Flexible• Comprehensible• Reusable• Portable• Interoperable

Architecture

Interface Class and Dependency

IRow

Segmentation PositionUpdate

use

<<interface>>IRow

userealise

Package

related classes

name

Active Class

name

Processes

• Method in passive class - called from main• Method in passive class - linked to an Event• Method run in active class – explicit start

Specified in UML by Statechart Diagram

Signals and Events

• Signals are asynchronous events

• A Signal or Event is a Class

• A method may have a send dependency

on a Signal

• A method that recieves a Signal

has a use dependency

Sensors, Actuators and Control Architecture for Embedded Systems

• Sensors have passive interfaces with event methods

• Actuators have passive interfaces with event methods

• Control is active and uses sensors and actuators

Your Report - 4!1.1. Requirements SpecificationRequirements Specification

2. Architecture

2.1 Criteria

2.X Module Interfaces

2.T Integration Test Specification

3. Modules

3.X.1 Module Interface

3.X.2 Module Design

3.X.3 Module Test Specification

4. Implementation

5. Test