Simta,
Each organization has its unique process. To give you an overall picture here i go...
1. Manpower planning has been done after in depth discussion which happens with the Business Heads, relevant Project Managers, technical managers and the HR representative on the forthcoming or existing projects.
2. After giving due consideration and understanding the requirement needs, manpower plan is being drafted, which includes the pre-requisite for the project such as number of resources required and by which date the resources should be on board, this is also called Service Level Agreement (SLA).
3. Once Manpower planning is done, a resource requisition form (RRF)is being prepared which contain the Job Description of the position.(Hope you are aware of Job Descriptions)
4. This RRF comes to the HR team after necessary approvals from the business head.
5. HR person approaches the RMG team to check, whether there internal resources availabile who can be transferred to the new assignment.
6. If this option doesn't work out, he starts with the recruitment process which includes sourcing relevant profiles and calling candidates and screening them on their communication skills, technical expertise, attitude, qualification, experience etc.
7. Shortlisted candidates are being called for interviews and successful candidates clearing the interview have been offered and on boarded.
Hope you would got some clarity :)
Cheers
Prakash