software engineering 1 the life cicle of software lesson 5

Software Engineering 1

Software EngineeringSoftware Engineering

The Life Cicle of SoftwareLesson 5


0. Feasibility Study

1. Project Planning and Management

2. Risk Analysis

3. Requirements Analysis

4. Design Analysis

5. Software Implementation

6. V&V (Verification & Validation)

7. Maintness

The Life Cycle of Software



1. Project Planning and Management

Cost, time and effort definitionTo show these informations we use: Gantt

Chart



t0= Kickoff-Meeting tF= Software Derivable

Jan Feb Mar Apr May Jun Jul Aug

T1:= V&V

T4:= Requirements Analysis

T3:= Architectural Analysis

T2:= Software Implementation

a Dependency

= Milestone with

deliverable



The Gantt Chart is made by Project Manager in the first phases

BUT

Gantt Chart is updated by Project Manager during the project

To make a Gantt Chart we use Microsoft Project



Project Manager must update the Gantt Chart when:

• a developer changes work

• unexpected problems in the development

• …



Some solutions for the updating:

• increase resource allocation (overtime – it does not always work…)

• assign more resources to certain tasks (it does not always work)

• try and break task dependencies (e.g. 80%, …)

• make it a parallel process by splitting the system in independent tasks

• … or end the project 20 days late





T1:= V&V




a Dependency

= Milestone with

deliverable





T1:= V&V




try and break task

dependencies

= Milestone with

deliverable





T1:= V&V




a Dependency

= Milestone with

deliverable





T1:= V&V


T3A:= A part of Architectural Analysis

T2A:= A part Software Implementation

parallel process

= Milestone with

deliverable

T2BT3B



Project Planning and Management deliverable (made by user and software provider):

• Gantt Chart

• a table with more information about activities, developers, …


2. Risk Analysis


• How can we avoid adverse event (planned or unplanned)?

• What can we do when an adverse event impact?



Risk Analisys deliverable:

• a document with a list of adverse event and it’s solutions



3. Requirements Analysis:(what the system should

do)

Functionals Requirements

NONFunctionals

Requirements



Functionals Requirements

What the customer requires



NONFunctionals

Requirements

Constraints of the system


Functionals Requirements:the services that the customer requires



NON-Functionals Requirements:• system properties and constraints

(e.g. reliability, response time and

storage requirements)

• a particular programming language

• development method



Requirements Analysis deliverable:

1. DSP (Checklist): requirements document

2. Test Planning: to check the requirements

3. User Manual



Requirements Analysis component:

1. DSP (Checklist):natural language and Use Case Diagrams

2. Test Planning:natural language anda set of pair <input data, output data>

3. User Manual:natural language and snapshot of the interface



Problems with natural language:

• functional and non-functional requirements tend to be mixed-up

• different requirements may be expressed together

• the analysis is difficult to understand



4. Design Analysis(how the system should implement the requirements)

• design analysis define the system’s architecture

• requirements and design are inseparable




LogicalArchitecture

PhysicalArchitecture

StructuralBehaviour

How the modulesare structured

How the modules are implemented

How the modulesinteract



Logical Architecture: an example

InterfaceUser Software Storage



Physical Architecture : an example

PC Internet Server


Design Analysis deliverable:

many UML Diagrams with different detail

• Class Diagram

• Sequence Diagram

• Interaction Diagram

• Deployment Diagram

• …



5. Software ImplementationWrite the code (e.g. Java. C++, …)


Notice:only in sub-activity of this activity

the code is written!!!


Software Implementationdeliverables:

o source code of the systemo document with some preliminary tests



6. V&V (Verification & Validation)

Make the test defined in the Requirerment Analysis

and some other test

Some of test are make by the developersOther test are make by other programmers




Several types of test:

• test (during the implementation)• unit test (after the implementation)• integration test• system test• -Test• -Test



-Test

A version of the System tested by the users inside the Software Factory

V&V deliverable:



-Test

A version of the System tested by some other users

V&V deliverable:



7. Maintness

• remove new bugs

• implement the change of requirements

• implement new requirements

software engineering 1 the life cicle of software lesson 5

Documents

software engineering

life cycle of software

software derivable

software provider

life cycle of software

deliverable t

requirements analysis

architectural analysis