Producción de Sistemas de Información Agosto-Diciembre 2007 Sesión # 2

Detailed Design Planning Construction Requirements Development Architecture Management Quality Assurance and Testing User Documentation Software Development Process (McConnell, 1998) Time

Software Development Models Waterfall Model Spiral Model Structured Model Rapid Prototyping Model Others?

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 K90329_S_021 (2) Systems Requirements Software Requirements Preliminary Design Detailed Design Code and Debug Test and Pre-operations Operations and Maintenance (Source: Dr. Szygenda, SMU)

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 (Source: Dr.Oard, LBSC-690)

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 K90329_S_026 (2) Users 1.0 Survey 2.0 Analysis 3.0 Design 4.0 Implementation 6.0 QA 9.0 Installation Management Operations 8.0 Database Conversion 5.0 Acceptance Test Generation 7.0 Procedural Description (Source: Dr. Szygenda, SMU)

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 Choose Functionality Build Prototype Initial Requirements Write Specification Create Software Write Test Plan (Source: Dr. Oard, LBSC-690)

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)

Para la próxima sesión Buscar información de al menos 4 modelos de desarrollo de SI. Realizar un análisis comparativo que incluya características, ventajas y desventajas de cada modelo. Entregar por escrito tus respuestas, a la hora de clase. NOTA: No se recibirán actividades por correo electrónico.