We've been working with certain clients for a very long time, some for more than a decade. This is fairly unusual in this industry in Ireland, with clients preferring to change designers from time to time to 'keep things fresh' as it was explained to me a few times. Nothing could be more wrong and misjudged.
Brands are created initially at a company or product launch. They are based on the story behind the product and the company, it's philosophy and ethos, and the way it operates or the way the products are made. A good brand will give the right visual expression of what the company and product stand for. Once the hard work of creating that brand has been completed, it continues for the life of the product or company. A brand should never stand still, it just cannot remain the same always. To do that would not reflect the progression of a company, and it would make the brand stagnate. That is not to say though that a brand needs to radically change occasionally to 'freshen things up'! That can have an equally negative effect on the message conveyed by the brand. It would confuse and would negate anything that went before it, losing all the benefit from the work in establishing the brand.
Brand don't just exist, they evolve. That evolution is gradual, just like the evolution of a product or company is. It's a gradual change over years which makes sure the brand is still fresh, but without losing it's established tradition and recognition factor. This approach will not confuse and will reinforce the message a company communicates: we are evolving with you.
Wether that evolution is lead by the same designers or not is in a way irrelevant. It is an advantage to have the designers involved in the long-term project, to give them a sense of longevity of project, to make them stakeholder in the project, not just a service provider. It is far more satisfactory to establish a longterm relationship with a group of designers than to go from one to the other and having to start over again every time. An established working relationship with a designer or any service provider will ensure that the product and company is better understood, and that their input is far more based on experience than just the 'new thing'. Designers are good at designing, and as such should not have fixed style or look. A designer will always look at the market and at trends, and keep in mind the latest developments in branding, to ensure that the design work for the brand in question will stay fresh and on target.
Occasionally a total rebrand is needed when a product or company goes through a complete change and need a new direction. An argument can be made that a new designer is needed for that. But again, as the company changes so should the design approach. However, the designer that has been involved in a decade or more of work and knows the way the company and the individuals involved think and work, and has grown with the company on a long journey. There is history there that must be considered. That history is the basis of a working relationship which will help a company in a difficult transition and will ensure that the message is still on target while utterly changed.
As designers we design things for specific needs and messages, and we adapt our work 'styles' to that need, not to a fixed visual style. Keep that in mind, and find the right designer for you and go on that journey or brand longevity.