A product development has the below stages and  Idea generation will be the first stage.

1.Idea generation

2.Market Analysis

3.Brainstorming with the Stake holders

4.Design the prototype  and /or Proof of concepts of the product

5.Refinement of the Prototypes

6.Development of the finalized product

7. Implementation - Release to Production

8.Provide the required Support and Maintenance

Many of the products have been shelved after reaching the stage of prototypes due to factors of the changing market and business needs. Almost of the New Product development undergo the similar phases and there could be be refinements happening after each phase starting from Market Analysis till Prototypes.These refinements could vary among companies.

I hope this answer helps.

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