Sistemas de Información
Agosto-Diciembre 2007
Sesión # 9
Software Development
Process
Planning
Management
Requirements Development
Architecture
Detailed Design
Construction
Quality Assurance and Testing
User Documentation
Time
(McConnell, 1998)
Evaluating the Software
Development Process
To assess the quality of the software
development process:
verify compliance with project
schedule and budget
verify compliance with initial
requirements
identify process metrics (SEI)
coding
testing
Software Development
Models
Waterfall Model
Spiral Model
Structured Model
Rapid Prototyping Model
Rational
MSF
Waterfall Model
Early focus on analysis of
requirements and design
Involves intensive documentation
and testing
Also known as “traditional model”
or “linear model”
Most widely used!
Waterfall Model
Systems
Requirements
Software
Requirements
Preliminary
Design
Detailed
Design
Code and
Debug
Test and
Pre-operations
Operations
and
Maintenance
(Source: Dr. Szygenda, SMU)
K90329_S_021 (2)
Spiral Model
Involves iterations of design, development,
and testing
Starts with a preliminary system version (v0.5)
After intensive testing, a first version of the system
(v1.0) is released
Small changes on the first version are included, as
necessary (v1.1, v1.2, etc..)
Substantial changes will be included in a new release
(2.0, 3.0, etc..)
Works very well on incremental development
projects
(Source: Dr. Oard, LBSC-690)
Spiral Model
1.2
2.3
0.5
1.0
2.0
(Source: Dr.Oard, LBSC-690)
3.0
1.1
2.1
2.2
Spiral Model
Involves several task regions in each
iteration:
Customer communication
Planning
Risk analysis
Engineering
Release
Customer evaluation
(Pressman, 1997)
Tends to be very expensive !
Structured Model
Draws from structured analysis,
structured design, and structured
programming
Involves parallel activities
Requires several teams
Works very well in large projects
with self-directed teams
Structured Model
Users
Management
1.0
Survey
2.0
Analysis
Operations
8.0
Database
Conversion
3.0
Design
7.0
Procedural
Description
4.0
Implementation
5.0
Acceptance
Test
Generation
(Source: Dr. Szygenda, SMU)
6.0
QA
9.0
Installation
K90329_S_026 (2)
Rapid Prototyping Model
Goal: explore requirements
Without building the complete product
Start with part of the functionality
That will (hopefully) yield significant insight
Build a prototype
Focus on core functionality, not in efficiency
Use the prototype to refine the
requirements
Repeat the process, expanding
functionality
(Source: Dr. Oard, LBSC-690)
Rapid Prototyping + Waterfall
Update
Requirements
Initial
Requirements
Choose
Functionality
Write
Specification
Create
Software
Write
Test Plan
Build
Prototype
(Source: Dr. Oard, LBSC-690)
Rational (IBM)
A process for software engineering
arranges in disciplines and phases
Emerged in 1998, from the “Rational
Approach” and the “Object Process
3.8”, from IBM
Rational (IBM)
• Core Process Workflows (6)
• Core Supporting Workflows (3)
MSF
Microsoft Solutions Framework (MSF):
An approach to IT project management
Based on Microsoft best practices
To improve project success rates
To increase solution quality
To increase business impact
To improve process in terms of CMMi
To support compliance with ISO standards
MSF Models
Software Development
Models: Discussion
How can we decide which model to
use for a particular software
development project?
How can we assess the quality of:
The software development process?
The software product?
Selecting a Software
Development Model
Choose a model, in terms of:
the nature of the system to be
designed and developed
the time and budget restrictions
the methods and tools available
the required deliverables
(Pressman, 1997)