Creating a conference is a very worthwhile activity—however, even organizing a two-day workshop can be a logistical nightmare that requires a dedicated support staff to pull off efficiently. If you don't have it, you can still get it done, but it still requires a lot of planning and a lot of effort.
I was invited to participate in the scientific committee for a workshop to be held here on campus and hosted by my institute. Even though we had the administrative staff taking care of organizing room reservations, hotel blocks, catering, name badges, preparation of the formal program, and so on, there's still a lot of work involved, particularly if you're the chair. You'll need to contact (and sometimes harass) speakers, look for funding, recruit attendees, advertise like crazy, and so much more.
However, if you can make your workshop a part of someone else's existing conference, then you can remedy many of these problems—the existing conference's infrastructure goes a long way in supporting your workshop and its goals. Frankly, if I was going to try to start a new workshop that would take on its own independent existence, that's the route I'd choose. If the workshop inside of another conference received good feedback, only then would I try to make it an independent event in the future. In that time, you'd also have figured out who the other "major players" are who could serve on future scientific committees.
The conference we started was created by our institute, so dividing up the responsibilities was relatively natural: the head of the institute was the head of the conference, and we divided up the work of programming the sessions among the members of the committee.
If you don't have that option available—if, for instance, you're the primary mover and shaker behind the workshop—that puts more work on your plate.
If you're doing a workshop under the aegis of a larger program, then I would think you would be the chair of the program. You could select other people to be on the organizing committee, but as the person doing the recruiting, you're going to be the one the others look to for guidance and decision-making—at least at first.
So I think the "founder" is going to be the general chair or the organizational chair, at least the first time around. Should the conference survive to have a second iteration, then at that point establishing some sort of successorship makes a lot of sense, because nobody really wants to go through the process of organizing all of those details every other year; it's too much work.
But, if you want to know, the order did go something like this:
- Steering committee of institute decided to hold conference
- Steering committee appointed emeritus faculty member as program committee leader.
- Steering committee appointed junior faculty as committee members.
- Program committee came up with several tentative plans.
- Steering committee decided on final overall structure.
- Program committee scrambled to find speakers to fit new structure decided on by SC.
- Program committee puts together advertising, recruits speakers, organizes poster session, organizes conference structure, and performs other duties as needed.
- Organizing team handles payments, attendance and registration issues, travel and accommodation issues, operation of conference, and so on.
The other thing to consider is that the planning for something like this typically requires on the order of 12 to 18 months, even if you're just doing an event locally hosted at your university (like ours was). For something more complicated, you may need even more lead time.