Product lifecycle begins with the inception of an idea, discussing the problems it is expected to solve, the potential market for it, the features it must have, etc. Once that has been established, the next stages are engineering and design when the specifications are decided and all the inputs frozen. After review and approval, it then enters the shopfloor for manufacturing. Sales and marketing happen in parallel, at which point the pricing is also decided based on customer interest. Once the product is ready, it is tested and distributed. Post-market service and disposal of obsolete products completes the lifecycle.