How to Avoid the Decline Stage of the PLC?

Preventing from Reaching the Decline Stage
Eunse
According to Christensen's Disruptive Innovation strategy, there's no way of just staying on the top of the game for good. Personally I agree with his view and would say it's best to come up with a better product before the current product hits the decline stage and takes the whole company down with itself.

Prevention of Decline Phase of PLC
Matt Cooper
In markets where the product cannot reach saturation, for example foods where you need to re-buy daily then you can avoid the possibility of reaching your peak selling point (bearing in mind that the population and therefore consumer numbers are always increasing).
However, also some other non-necessary products can go on for a long time, Coca Cola is very much similar to the food example but unlike food it has had to take a strong hold of the market and almost monopolise it through its ability to benefit from economies of scale.
But otherwise, I'd agree its almost impossible to avoid the decline phase.
Most companies try to come up with an addition/advancement on their previous products to hit new peaks with their newer products as they hit the decline with the old ones. E.g. Phones- phones with cameras- phones with bluetooth-phones with internet etc.

Avoiding the Decline Stage of the PLC
Mohanned, Tunisia, Member
Remember the product cycle life is not a linear process and many products pass straight to the decline phase after the stage of introduction.
The life cycle depends on involvement of consumers and the type of product, for example the life cycle of technology products is often shorter than other types of products.
During the product cycle life, the marketer can add innovations to the product such as packaging improvements.
But besides the exceptional categories mentioned by @Matt Cooper, I think that any product eventually must pass to the phase of decline, it’s a natural phenomenon.

How to Avoid the Decline Stage? Example from the Auto Industry in India
shiju daniel, Strategy Consultant, Member
If products do not evolve over time they will eventually phase out. For example in India Ambassador car company was there, what they were intending to do was to keep the old Ambassador model as a classic model with very powerful v6 engines or so, and can introduce small "K" cars for public, and this strategy introduced first by Maruti Suzuki and now they are market leaders and continuously holding that place by reinventing themselves by doing market research and finding product gaps, for ex, they introduced small cars with AMT automatic gear system which was badly required in the market, there are other factors also like good customer experience.
Customers should be addicted by the kind of pampering the service stations providing to them, you can say a "tension-free ownership" experience, this word may not be relevant outside but within India where service is "taken for granted" even if you are ready to pay a premium to get a better service experience.