Modern services delivered in Software As a Service(SaaS) model as Multi-tenant applications need also specific development methods to fit this new ecosystems.
One of possible models is Evolutionary SW Development EVO Highly Incremental Model from HP
EVO uses small, incremental product releases, frequent delivery to users, and dynamic plans and processes.
The Evolutionary Development Model for Software (Original PDF)
The evolutionary development model for software (Web Edition)
Evolutionary Development Presentation (PPT)
Software Development: Iterative & Evolutionary
Creating Web-Based Learning Systems: An Evolutionary Development Process
