Just a nugget.
A business idea without proper management plan is one that can be considered to be dead on arrival. Business success revolves around excellent management plan first before capital size. With a large capital chunk into any business that's lacking in proper planning, such business can inevitably collapse, turning into a wasted investment.
But on account of proper management structure on ground with even the small size of capital, it can be sustaining to such business's success in the long ... Experience should be considered as a key asset in business planning and as a key factor it's important to always involve those with experience in the area of business when planning. Never neglect this!
Who in his right sense will want to start a business without any plan? Even if you steal the capital, it's unwise to start business without any plan, it will be better to do a give away with the capital than incur losses that you can avoid from beginning. You need to have a business plan right from where it start to when the business profit will be coming back, not doing that is as good as putting money on a black magic door with one way, you will never recover from the money.
However, you need to also know that having a business plan doesn't guarantee the success of that business because plans are ideas and solutions that are drafted on papers, the reality might have some skewness that will deviate from real idea that you have from the beginning. It's your responsibility to make sure that you try as much as possible best to make it align with what you have as planned or you adjust your plans to the real situation of the business.