The common belief is that a product life is from when the first product is sold until the last product is sold. In reality it starts when the idea is created. The shorter the product development cycle is the longer the product life is.
Every product start with an Idea. The process of turning that idea into a manufactured product is called "Product Development".
Turning an idea into a concept is developing frameworks of the electronics, mechanicals and economics that will carry the idea forward towards reality.
The concept is then proven with a concrete design of both the electronics and mechanical. The cost of the design can be evaluated as well as the manufacturability.
Through prototyping the design is further refined and tuned to meet the product function and manufacturing requirements.
The final design is committed to tooling. It is important that as many design issues are found in the previous steps as the cost of design changes raises exponentially at this point.
The tooling is qualified that it meets the design. All quality and manufacturing procedures and documents are finalized a small production lot is verified and the product is placed into production.