Although one must constantly try to improve each existing component of a web presence, the key to avoiding most maintenance, customer care, and expansion headaches lies in keeping logical continuity.
Mistake: An overwhelming majority of companies achieve the opposite.
Result: A large portion in time and resources is invested in systems which are eventually scrapped only to be reinvented again.
These resources would be better invested in building a solid, long-term, and scalable web presence enabling a company to focus on expansion while leveraging web investments of the past. This applies within the ERM space as well. (Read: fictitious sample ERM plan).
Microsoft.com is a good example to watch. Since 1996 they redesigned their network of sites only once in 1998 without departing too much from their earlier version.
Result: Users have had time to learn the underlying logical sequence within their information architecture, interactive elements, and visual design. Overall usability is much higher as a result.
Re-designs are not necessarily bad but once you have initiated a logical pattern to interaction and usability try to keep some continuity.
This is one of the reasons why companies that slowly materialize on a clear long term vision usually end up being more fortunate than their counterparts who do not. See: Microsoft and Cisco.
Although one must constantly try to improve each existing component