Design/Redesign As a Process
In its essence, redesign is a never ending process repeating itself in specific cycles. This may seem a rather complicated statement to begin with. However, it is conveying a very simple message. Redesign is not something that occurs only once, even if one may perceive it as such at the first sight. As a matter of fact, there is nothing like a perfect redesign, for two reasons:
A conflict between the desired behaviour as expected by the web or mobile application owner (most frequently, a conversion of a kind) and the goal the web user would like to achieve. Certain consensus can be achieved through correct setting of business goals so that they respect users' natural behaviour. However, there will never be a perfect overlap of the user's and owner's goals.
Time. Time will always play against you. Not even the best of redesigns would stand the test of time. All factors change in time, from trends in terms of design, functionality and technology, to preferences, needs and natural behaviour of users themselves. You fail to adapt and users will go to somebody able to deal with their needs in a more efficient, faster and simpler way,
Takeaway: Redesign is a process. Trends and customer preferences change in time.