I've seen both sides of the college hire process with my department, so I'll focus my review on college hires.
Departments constantly monitor their available staffing vs. program demand, and during the first quarter of every year they determine their hiring goals, including college hires. At this point, the sections that need additional resources will submit a request to HR to review for applicable skill-sets.
Upon selection a handful of candidates (could be as little as four, could be twelve depending on the demand) IDS will contact the individual, and arrange for an on-site interview. Raytheon reimburses all expenses for the interview, including travel (at the federal mileage rate, or airfare for significant distances [20 miles, 50 miles? I can't quite remember,]) lodging, and a rental car if necessary.
Once on-site, candidates have a brief introduction (duration: 30 minutes) by HR describing the process, telling us what their goals are and who they would be meeting with. At the conclusion of the HR intro a few younger engineers meet with the candidates and act as their escort for the day.
At the conclusion of the HR introduction, candidates next meet with the potential section managers (duration: 30 minutes.) The section managers give a brief overview of what kind of work they perform, what programs they work on, and some of benefits of working at Raytheon.
After being introduced to the potential section manager, the candidate will generally undergo three one on one interviews with senior members of the section (duration: 30-40 minutes each.) The range of questions they ask will vary, but generally they're trying to determine: your interpersonal skills (will you work with our group,) your expectations (will our group work with you,) and your technical skills.
At conclusion of the personal interviews, the section manager generally takes the candidates and the escorts out to lunch (duration: 45 minutes) at a nearby restaurant to facilitate a more candid conversation amongst the group.
At the conclusion of lunch, candidates are gathered for a small out-brief (duration: 20 minutes) answering any questions the candidates might have, outlining when they will be notified, and reminding of the reimbursement procedures. This is generally the last contact the candidates have with Raytheon for the day.
Now, after the candidates have left, the section manager usually distributes a rating matrix to the three senior section members who conducted the interviews, to evaluate the candidate over a range of criteria. After receiving their ratings, the section manager will gather the senior section members to discuss the ratings and decide upon offers.
After making selections, the section manager will inform HR who their top candidates are, and HR will send out offers.