In over a decade of writing software for the web I’ve never once said I was disappointed for having realized the path I was on was not the right one for the job. In fact, quite the opposite is true. Knowing that you are doing just enough but not a bit more work than is necessary to accomplish a goal provides a powerful boost to future productivity. I have found that short feedback loops are as beneficial in business processes – that is, the process of development – as they are in writing automated tests for code.
The bottom line is, establish rapid feedback cycles in your project where you and your team communicate regularly about progress, pitfalls, and successes, and you will be unstoppable.