Everything in life changes to keep up with the times. Business logos, which are signs by which businesses are known by to the consumer, also change to keep up with the times and remain fresh and contemporary in the consumer's mind. There is a time when a business logo needs to change to reflect the changing business world. This need not be a complete makeover nor does it need to undo the consumer confidence and recognition the logo has come to stand for.
Bring to mind the most famous companies and it is just as easy to visualize their respective business logos. Thinking of McDonalds should bring to mind the famous double arches or considering Volkswagen and the VW sign springs to mind, and Nike brand shoes and the famous trademark should be easy to visualize. This doesn't necessarily mean that their logos must remain the same forever, even though famous nor does it necessarily mean that altering them to keep them contemporary need destroy the trust and brand recognition the logos have built over the years.
In the same way that a company changes products to modernize them and keep up with the customer's needs, the logo is often changed to keep up with the changing needs of the consumer as well. A logo that never changes may hint that the company is not changing their products or outlook to keep up with the customer's need. On the other hand, small changes that modernize the logo indicate the opposite that the company is evolving with the times.
Changing the logo of a company drastically can produce negative results but small changes can actually enhance the company images. When considering changes in a company logo major design elements might remain the same. For instance to toss out the double arches in McDonalds might alienate the customer and lose the recognition the logo has built over the years. However, changing the design of the arches or making subtle color changes can and has enhanced the image make it contemporary without losing the logo's impact.
Many world famous brands have made significant changes to their logos but the changes have been so gradual and so subtle that the consumer has not even noticed it.
The famous McDonald's Golden arches were actually an architectural design concept, which became part of the logo in 1962. The original M was a rounded pair of arches while today's M has a more angular design. The changes were very gradual and the main design concept of M was retained so that the changes as with many logos simply slid by unnoticed on the surface.
This applies equally well to companies such as Sony, and Nike which have changed their logos subtly over the years in ways so minor they have almost passed unnoticed.
If a business has built successful consumer relationships and when the consumer connects the logo to the product in a positive fashion then changes to the logo should be gradual. However if the company is not building a successful relationship with their market, the consumer, then an entire logo redesign might be necessary. If a logo is not being connected positively to the product by the consumer, then it is not effective, and a complete redesign may be in order. When a logo is functioning correctly though, subtle changes may be all that are required.