The best Business Analysts I have worked with have been consultants that had been previous developers (Technical Programming and Relational Database background) in places where they had heavy client-facing interactions. They understood the whole SDLC process and could take a project from beginning to end, filling in where needed in any phase of the project.

The SDLC Phases are:

Project Selection - (When I get to a site, the project has usually already been selected...with a projected budget and deadline)

Initiating

Planning

Requirements Definition

Functional Design

System Design

Programming and Development

Integration and Testing

Installation and Acceptance

Closing

Maintenance

Retirement (Sun Set)