The 6 Stages of a Successful Product Lifecycle

A hardware product has discrete stages in its lifecycle from concept to completion, or more colloquially: from Cradle to Grave. Each of these stages has a purpose with its own set of goals and exit criteria. If not administered properly you greatly increase the risk of a less than successful product launch plagued with delays and budget overruns. In the worst case, you completely miss the market window and your chances of any success.

Did I scare you, yet?
Good. Now let’s start at the beginning...

Once a product has been conceived, whether it was from a late night fueled by alcohol and bar room banter or a strike of lightening inspiration leading to a quick sketch on a napkin, the Product Lifecycle begins.


The 6 Stages of Any Hardware Product Lifecycle

  1. PRD - Product Requirements Documentation
  2. EVT - Engineering Validation and Testing
  3. DVT - Design Validation and Testing
  4. PVT - Production Validation and Testing
  5. MP - Mass Production
  6. EOL - End of Life


Let There Be Light

The first step is to write down the requirements in a formal document called the PRD (Product Requirements Document). Why is this important? Because without requirements or performance specifications, you won’t ever know if you’re done developing. What size does the product need to be? What temperatures does it have to operate in? How fast does it have to move? How bright do the LEDs need to be? What age is the intended user? How long must the battery last? You get the idea. Without these specifications formally laid out, you run the risk of going down a rabbit hole and spending too much time and money on something that is not required.


A Proper PRD Includes

  • The complete list of features to be included in the product
  • The specific performance metrics each feature must meet
  • Estimated production volumes
  • Target costs
  • Target product release timelines
  • A product roadmap

The Product Manager is responsible for leading and authoring this document, but they must solicit input and final sign-off from all the other team leads: Engineering, Sales, QA, Executives, and Marketing. Once a revision of the PRD has been approved by all these team leads, it becomes your dogma and all subsequent product decisions must conform to what is written in the PRD. It is acceptable to ratify the PRD and create subsequent revisions as new information becomes available that impacts your earlier decisions, but each new revision must be reviewed and approved by the team leads, as well.



Next comes the fun part, more formally known as EVT. In this stage the engineering team uses whatever means necessary to implement each of the features outlined in the PRD. The goal of this stage is to prove that it is humanly possible, without defying the laws of physics, to design and build an instance of the product that meets the functional requirements in the PRD. But keep in mind that the components selected and the processes used to assemble them don’t necessarily have to be those that will be used in the final version of the product. Duct tape and hot glue are ok at this stage, as long as they allow you to build something that functionally works and passes your specification metrics.

The primary goal of Engineering Validation and Testing is to identify any and all risks of the requirements outlined in the PRD and find ways to remove or greatly mitigate them. This may take several iterations and millions of dollars in research and development, but a product doesn’t leave the EVT stage until all the functional requirements and performance metrics have been met.



In the DVT stage, the goal is to work your way towards the final look and feel of the product. This is when you start selecting materials and mechanical designs that meet the final form, fit, and aesthetic requirements outlined in the PRD. Materials and components selected in these revisions are candidates for the final production version. If possible, instances of your product built in the DVT stage can be shown to potential customers to start soliciting feedback and testing product-market-fit. This is actually valuable to do at this stage before you begin investing significant capital dollars for the materials, tools, and processes required to start manufacturing.

A product can exit the DVT stage once there is an instance built that meets all functional and aesthetic requirements in the PRD while using candidate designs and components for the final production. This version may in fact be very close to your final product implementation and be indistinguishable to the untrained eye, but possibly created with lower volume manufacturing and assembly processes.



Now it’s time to relinquish control and engage in serious conversations with your suppliers and manufacturers. This is the PVT stage where you are confirming your DVT product can in fact be produced at the volumes and target costs listed in the PRD. Since more often than not you will be outsourcing the actual manufacturing and assembly of your product, you must engage with these suppliers to solicit feedback of your design to make sure you can achieve the production goals.

Hopefully this only requires a few small changes to your DVT model, like replacing a part with a cheaper pin-compatible version or slightly changing the draft angle on a custom mechanical part so it will eject more reliably from the injection-molding tool. But, in some worst case scenarios you may have to go through major overhauls or design changes to make your product ready for mass production. For this reason, it is best to actually begin talking to your suppliers well before you enter the PVT stage, so you can help ensure it will be successful by incorporating some of these DFX (Design for Manufacturing, Design for Assembling, Design for Testing) principles upstream in the product lifecycle.

The other goal of the PVT stage is to begin solidifying the production processes and setting up the supply chain. A great way to do this is to simply build a pre-production run of your product using the actual supply chain and manufacturing assets. This is the best way to see where the weaknesses are in your production ecosystem and determine if you’re ready to start increasing the volume and crank it up to 11. You will be working very closely with your manufacturer at this point - often on-site. So, don't expect to be getting anything else done in the office.

To exit PVT, the manufacturer must sign-off that the supply chain is setup. This means parts can be ordered at acceptable lead times and pricing and the assembly and test procedures are repeatable and reliable. You must also sign-off that the performance and quality of the final products meets your standards. Don't wait until Mass Production to check this - it will be too late.


Products for the Masses

The scariest yet most exhilarating stage is the Mass Production of your product. Of course “Mass” is a relative term and specific to your product and market on exactly how large your MP sizes are. But, when a product reaches MP it means you are producing and selling customer ready versions of your product at some meaningful quantity. Again, depending on your product and market on how big and how often each production build is, but more often than not, a product is produced in several batches over time with each batch increasing in volume size.

At this stage, the bulk of the responsibility is on the manufacturer to procure the parts, assemble, and test them to meet your production demands. But, you still have responsibilities to ensure the production quality and yields stay high while costs start to decline. You must support the manufacturer as necessary to achieve these goals. This may include working with procurement teams to build up a strong supply chain to keep costs and lead times low, or working with the manufacturing teams to continuously find ways to improve efficiency, increase yield, and lower production costs.


C'est La Vie

A product may come to its end of life (EOL) for various reasons. The best case is you have developed its successor, which is better, faster, cheaper, stronger, smaller, whatever. And so the original product is stopped or ramped down in its production. The worst case is a major flaw was discovered and the production line needs to be halted immediately and all existing products possibly recalled. The point is, one doesn’t simply stop production of a product when its time has come. There are several peripheral tasks that need to be implemented once the decision is made to EOL a product.

First, what is to be done with the existing completed products, also known as Finished Goods? Are they to be recalled and destroyed? Can the sales team continue to sell any remaining products in Finished Goods Inventory (FGI) but not order any new ones to be produced? The same questions must be answered for any remaining raw materials and components that haven’t been assembled or consumed yet. Can they be returned to their original suppliers for a refund? Can they be saved for use in other products? Do they need to be disposed of? The answers to these questions are referred to as: Product Disposition.

The point is, there is often a lot of capital invested in the finished goods and raw materials, and it’s important to leverage them as much as possible either by converting them back into liquid capital or moving them into another product revenue stream. Unfortunately, there will always be some loss where goods must be disposed of at a cost, but hopefully through good planning during the EOL stage this loss can be minimized.


The Devil is in the Details

The goal of this article is to articulate the fact that there are subtleties to the lifecycle of a product, and it's imperative they be taken seriously. A good Operations Manager will clearly define the Entry and Exit criteria for each of the discrete stages, minimizing "waste" and increasing productivity.

Too often we get caught up in the excitement of developing a product and bringing it to market and don't set ourselves up properly for success. Only the most successful companies know to take a breath, clear their heads, and give due attention to all the peripheral tasks associated with Product Lifecycle Management.

PLMMichael CorrPLM, DVT, EVT, PRD, MP, EOLComment