The product lifecycle is made up of four high level phases, during the operational life of a product it will move through these phases from market introduction through to product retirement.
This is the phase which the product first hits the market, during this phase the Product manager informs the market, makes the product available to its target audience, collects feedback from early adopter on how to potentially improve the product and iterates quickly and strategically.
During this phase the market begins to adopt the product and demand increases, potential competitors may also enter the market with similar products; the Product manager must step up marketing efforts as well as ensure that the product is available. The goal is to continue to iterate the product with new features based on customer and market input and capture as much of the market share as possible.
As the product enters this phase, growth tends to flatten out, most of the market has been captured by yourself or competitors, there are no more untapped customers, during this phase the marketing strategy changes from acquiring new customers, to stealing your competitors customers. The product generally has iterations with fewer new features.
As the market sentiment changes or new disruptive technologies begin to emerge the product enteres its decline phase, during this phase the product manger's goal is to timely and gracefully remove the product from the market while developing the subsiquent iteration to provide the marekt with the same value, however either leverging the new disruptive technology or adhering to new market sentiment.
All products will face an end-of-life market event, that is to say as the market changes, be it for socio-economical reasons or due to disruptive technology almost all products will face retirement. A savvy product manager will foresee this shift in the market before it happens, and begin a wind-down of the product while starting the innovation process for its replacement.
Products are not valuable in themselves, their value extends to the service they provide. Often times as in the classic example of vinyl records, a-tracks, tapes, music CDs, Digital music players, and now streaming services the demand for the service was always the same, however the mechanism which the market consumes the service shifts as new technology emerges.
Another example is the horse drawn buggy, to the combustion engine, and now electric car, the service the market demands has always stayed the same, however the medium has changed, the difference between these two examples, is that the catalyst for the electric car is arguably not technology. The number one driver is consumer concern over the impact of carbon emissions, the technology just makes the transition feasible; without the driver, despite the technology existing the product would fail.
The above is a high level abstraction, the four phases are far more involved and iterative in nature. As the product moves through its phases the rate of innovation slows and the source of primary insights shifts, though one should never ignore any insights regardless of their source, one should keep in mind the Sigmund Freud's theory that the conscious and unconscious mind imply that what people think, say, and do can diverge due to psychological conflicts and repressions. Or more succinctly:
What people think they doWhat people say they do What people actually do
are three distinct things
In the early introduction phase iterations will generally be rapid in nature, what "rapid" means depends on the industry, in software this could mean monthly if not weekly, however in the transportation industry this could mean annually. During this phase it's best to gain insights from early adopters, these insights can propel your product into an exponential growth phase, or they could result in the death of your product. It is important during the introduction phase to focus on aligning iterations to the value proposition. There will be a lot of early adopter feedback, however it is important to qualify this input with long term vision and strategy while maintaining early adopter enthusiasm.
Ideally the product will gain traction and transition to an exponential growth phase, this phase is often the result of strong marketing and early adopter satisfaction. During this phase one should focus on market analysis, look for customers you want and understand how your product can fill the need(s) they have. Iterations will slow down, again depending on the industry, however the goal will be to capture as much market share as possible without frustrating existing customers with changes.
Over time your customer base will grow, competitors will introduce their own products which will solve the same customer problem. During this maturity phase the market becomes saturated, there are no more new "virgin" customers; during this phase the product manager must walk the tightrope of keeping existing customers satisfied, while trying to entice the remaining market to switch to their product. During this phase one should rely more heavily on analytics, how are customers using the product, how can you improve engagement, how can you offer more value than your competitors. During the maturity phase enhancements may be annual and they should be evidence-driven and focused on maintaining customers, while looking to entice competitor's clients to switch.
Finally the product will eventually enter the decline phase, this phase can catch even experienced product managers off guard, most likely a disruptive technology emerges and a new product enters the market which provides the same value proposition, but faster, better, cheaper or any other reason which causes the market to shift to the alternative. Ideally the product manager foresaw this disruptive technology or shift in market sentiment and has already been working on transitioning their existing customers to the next iteration leveraging the new disruptive technology or adhering to market sentiment. Enhancements will be strategic in nature, aimed at transitioning existing customers to the next iteration of the product.
Conclusion
The operational product lifecycle is a minefield, initially it focuses on rapid iteration and entering the growth phase as soon as possible and ideally before competitors. Once the product reaches maturity and the market is saturated, the aim is to maintain customers, while enticing new ones to switch to your product. Finally it is essential to be prepared for an end-of-life market event and have a transition strategy to ride the next wave of innovation or market sentiment. In the ideal world it is your organisation that provides the innovation to disrupt the market.