How to find a business idea to be able to work independently?

Hi everybody,​I work for a big company and it's a very good company, nice perks, good salary and good career prospects, so I don't really have anything to be upset about and I am comfortable in my current lifestyle.​The only "problem" is that I have always had what you might call "the entrepreneurial bug" and sinceI was really young ( I'm now 30 ) I've tried to launch many, many websites ( I'm a software developer )in the hope that I could make something work.​I like my place of work very much, but I feel like I am not complete and fully motivated unless I amworking on something of my own.​​Here comes the big problem.​​Even though I tried many times to launch something, nothing ever worked, not even slightly.​Admittedly, I learned many things about launching a new product/service thanks to my failures and my persistance during the past years, but nothing worked and I don't have any idea how to find a good service that will work and that people will want to use and that I can develop without a whole team of 20 people ( marketing, research, analysts, ecc... ).​Also, something that influences my decisions is that I don't have enough money to just leave my job and try to make a new company succeed while working only on that and nothing else.​My question is:How would you suggest I go about to find an idea that will work?​Please note:even though I'm a software developer, I am not into freelancing, I'd like to launch something in the "Software As A Service" field. see hubwealthy.com/wealthy