1 Notes content copyright © 2004 Ian Sommerville. NU-specific content © 2004 M. E. Kabay. All...

1 Notes content copyright © 2004 Ian Sommerville. NU-specific content © 2004 M. E. Kabay. All rights reserved.

Software ProcessesIS301 – Software Engineering

Lecture # 4 – 2004-09-08M. E. Kabay, PhD, CISSP

Assoc. Prof. Information AssuranceDivision of Business & Management, Norwich University

mailto:[email protected] V: 802.479.7937


Objectives

To introduce software process models To describe three generic process models

and when they may be used To describe outline process models for

requirements engineering, software development, testing and evolution

To explain the Rational Unified Process model

To introduce CASE technology to support software process activities


Topics covered

Software process models Process iteration Process activities The Rational Unified Process Computer-aided software engineering

Today I will suppress most of the slides we examine and focus on only a few critical points. Use the entire set of slides as a study guide and aid to review.


The software process

A structured set of activities required to develop a software system Specification; Design; Validation; Evolution.

A software process model is an abstract representation of a process. It presents a description of a process from some particular perspective.


Generic software process models

The waterfall model Separate and distinct phases of

specification and development. Evolutionary development

Specification, development and validation are interleaved.

Component-based software engineering The system is assembled from existing

components. There are many variants of these models e.g. formal

development where a waterfall-like process is used but the specification is a formal specification that is refined through several stages to an implementable design.


Waterfall modelRequirements

definition

System andsoftware design

Implementationand unit testing

Integration andsystem testing

Operation and

maintenance


Evolutionary developmentConcurrentactivities

ValidationFinal

version

DevelopmentIntermediate

versions

SpecificationInitial

version

Outlinedescription


Reuse-oriented development

Requirementsspecification

Componentanalysis

Developmentand integration

System designwith reuse

Requirementsmodification

Systemvalidation


Incremental development

Validateincrement

Develop systemincrement

Design systemarchitecture

Integrateincrement

Validatesystem

Define outline requirements

Assign requirements to increments

System incomplete

Finalsystem


Spiral model of software process

Riskanalysis

Riskanalysis

Riskanalysis

Riskanalysis Proto-

type 1

Prototype 2

Prototype 3Opera-tionalprotoype

Concept ofOperation

Simulations, models, benchmarks

S/Wrequirements

Requirementvalidation

DesignV&V

Productdesign Detailed

design

Code

Unit test

IntegrationtestAcceptance

testService Develop, verifynext-level product

Evaluate alternatives,identify, resolve risks

Determine objectives,alternatives and

constraints

Plan next phase

Integrationand test plan

Developmentplan

Requirements planLife-cycle plan

REVIEW


The requirements engineering process

Feasibilitystudy

Requirementselicitation and

analysisRequirementsspecification

Requirementsvalidation

Feasibilityreport

Systemmodels

User and systemrequirements

Requirementsdocument


The software design process

Architecturaldesign

Abstractspecification

Interfacedesign

Componentdesign

Datastructuredesign

Algorithmdesign

Systemarchitecture

Softwarespecification

Interfacespecification

Componentspecification

Datastructure

specification

Algorithmspecification


Design activities

Design products


The debugging process

Locateerror

Designerror repair

Repairerror

Re-testprogram


The testing process

Componenttesting

Systemtesting

Acceptancetesting


Testing phases


Systemspecification

Systemdesign

Detaileddesign

Module andunit codeand test

Sub-systemintegrationtest plan

Systemintegrationtest plan

Acceptancetest plan

ServiceAcceptance

testSystem

integration testSub-system

integration test


System evolution

Assess existingsystems

Define systemrequirements

Propose systemchanges

Modifysystems

Newsystem

Existingsystems


RUP phase model

Phase iteration

Inception Elaboration Construction Transition


Computer-aided software engineering Computer-aided software engineering (CASE) is

software to support software development and evolution processes.

Activity automation Graphical editors for system model

development; Data dictionary to manage design entities; Graphical UI builder for user interface

construction; Debuggers to support program fault finding; Automated translators to generate new

versions of a program.


Functional tool classification

Tool type Examples

Planning tools PERT tools, estimation tools, spreadsheets

Editing tools Text editors, diagram editors, word processors

Change management tools Requirements traceability tools, change control systems

Configuration management tools Version management systems, system building tools

Prototyping tools Very high-level languages, user interface generators

Method-support tools Design editors, data dictionaries, code generators

Language-processing tools Compilers, interpreters

Program analysis tools Cross reference generators, static analysers, dynamic analysers

Testing tools Test data generators, file comparators

Debugging tools Interactive debugging systems

Documentation tools Page layout programs, image editors

Re-engineering tools Cross-reference systems, program re-structuring systems


Activity-based tool classification

Specification Design Implementation Verificationand

Validation

Re-engineering tools

Testing tools

Debugging tools

Program analysis tools

Language-processingtools

Method support tools

Prototyping tools

Configurationmanagement tools

Change management tools

Documentation tools

Editing tools

Planning tools


Tools, workbenches, environments

Single-methodworkbenches

General-purposeworkbenches

Multi-methodworkbenches

Language-specificworkbenches

Programming TestingAnalysis and

design

Integratedenvironments

Process-centredenvironments

Filecomparators

CompilersEditors

EnvironmentsWorkbenchesTools

CASEtechnology


Homework

Required:By Wednesday 15 Sep 2004Submit written responses to these

questions:4.1 (8 pts)4.5 (4 pts)4.6 (5 pts)

Optional:By Wednesday 22 Sep 2004

Answer any or all of questions 4.2, 4,3, 4.4 or 4.8 for 2 pts each.


DISCUSSION

1 Notes content copyright © 2004 Ian Sommerville. NU-specific content © 2004 M. E. Kabay. All...

Documents

Transcript of 1 Notes content copyright © 2004 Ian Sommerville. NU-specific content © 2004 M. E. Kabay. All...