Roles and Methodologis in a Software Company

Hi Guys,
I have a problem for understanding deferent roles in a software company

can someone get a light on these questions

1-Who heads the development system of your organization?Who is doing the planning ,analysis,design,implementation and maintenance?
(please mention the names and the roles they have with a little description of every role)

2-What are the system development methodology You use in your company?for example SSADM, OOP, RAD, RUP, AUP?
If you acquired the information systems from off-the shelf products what is the process of procurement in your organization?

I am very thakful if you could answer my questions depending what is happening in your company
Thanks :)