Recently there was an interview with Allyson Hatfield with the Supply Chain Brain, which can be found here: http://bit.ly/1eY7UQ0
Allyson Hatfield is responsible for the demand planning for new products at Campbell Soup. Almost all the old line food companies have found that must innovate to survive and grow. That has meant that being able to plan how to handle new products is a key skill. She brings something very important to job beyond her business skills, that is a joy of discovery, because when something is new one has to be assertive in finding new information.
To plan for a new product, she starts looking at what products in similar categories are doing in the marketplace. But she also realizes she needs to physically see the marketplace, going to stores to see how similar products are promoted and sold. She brings a knowledge of the retail customers into her demand planning, so she can plan how they are likely to respond to the new product.
Any new entrepreneur has similar issues. But with knowledge of similar products and knowledge of the customers, intelligent guesses can be made on business levels. The chance to be successful will increase if you can know what to make and how much.