Marketing: how to assess whether there is a market for a new product

You should carry out a research on the customer demands to see if there is a read need in the market for your new product. The feedback or result will help you to decide whether to launch the new product on the market.
You should pay special attention to your competitors. Detect whether they are going to launch their new product onto the market. if the answer if yes that probably means there is a demand in the market for some new product. Then be quick and put on your rival product to coincide with them.