Is a startup a full-time job?

You don't need to work full-time in your startup from the beginning. It you're going in the right direction you'll most probably see some positive results (at least in terms of feedback) early on even if you cannot work a lot on it. If you're going in the wrong direction, well then spending more time on it will not probably help much.

With my first product I always blamed having a day job for not being successful with it but then I launched a second one (completely different) with much better results and on which I invested much less time on it (and still keeping my day job).

I guess what I'm trying to say is that you should not decide whether to work full-time on your startup until you see the product/idea is worth the risk

It has been for me so far!

My 15 year "day job" starting as a developer and moving into technical project management has given me some advantages in terms of being able to structure the work ahead, as well as actually execute the work to be done. However, even with that, starting up my own business has redefined the cliche "there aren't enough hours in the day". The business experience from my past work also helps immensely in terms of articulating my value-prop to different constituencies, the sales process, managing/hiring staff, and marketing & communications in general.

I can honestly say that starting my business asks more of every skill I have... yet that's also the attraction!

So you have an idea... what is the value-prop to your customers; what about your providers? Can you put together a compelling elevator pitch? Can you sell? Are you a developer? Can you make decisions and presciently see their implications further down the road? What about budgets, and financial projections? How well do you know your target industry, customers, and competitors? Do you have staff, know staff, or do you need to find those people? Have you ever managed a project of any kind?

These are the things that you'll face -- no one knows them all and so the idea of "knowing what you don't know" is a challenge unto itself. The point here is that while any smart start-upper is/should be capable of learning on the job and extending their talents into other areas, it all takes time.

Some days I have a plan with three action items on it, but the first item ends up being much deeper than initially thought, and takes the day... tomorrow starts two items behind. This is also where decision-making comes into play. Should you cut your effort on that item or is it wiser to push through? Sometimes I hate that thinking can take longer than I planned for ;-)

For my current start-up I have cleared the way (of a full-time job and other consulting gigs) to make sure I give it a full-court press. It also helps that I have some funding, but I'm still looking for that elusive 35 hour day!

You also know a truth that will be revealed to all part-time start-up founders eventually: there is no progress if you are not making it (I hate that one).

Best of luck!

Yes. A startup CAN BE MORE than a full-time job and from your question, it looks like you want it to be your sole income generator (if not right away, then at some point). So my answer to you is based on the assumption (which I gather from your question) - that your dream and passion is to do this startup and you have done your due-diligence around it and know in your heart and gut (and any other body part) that this is IT.

In this case, you should treat your startup as MORE THAN A FULL TIME job - Any less and you will be short-changing yourself and your dream and the potential to succeed - furthermore if you have partners/employees you will be doing the same to them.

Now that being said - if you have zero income and no other means to fuel your startup efforts, then you will have to compromise. So you may need to take on a full time job or a part time job or a consulting gig to keep things going UNTIL you can jump into startup mode in full time.

HOWEVER - this compromise can be a slippery slope (as you have already discovered from your PhD efforts which keep you from launching the startup). So until you start sacrificing (in time/money/efforts) and make the compromise in favor of the startup, you will always find it lagging behind your goals.

Getting this mindset of waking up first thing in the morning with your startup in your mind is half the battle. If you can do this, you can make the rest happen through sacrifices you will have to make.

Go get'em!

-Siva

Generally speaking, most businesses require your full attention. The most important reason for this is customer interaction. If you are not available to answer questions when people expect you to be, they will move on.

This isn't true of all businesses but it is true of most ...especially those that have the revenue potential of supporting full time work.