How can management consultants build lasting relationships with clients?

The skill of forging strong, durable relationships with clients is crucial for management consultants. 

However, clients are often wary of consultants, doubting their intentions or expertise. Clients may have unrealistic expectations about what consultants can achieve and in what timeframe. They may have other pressing priorities that can overshadow the consultant's initiatives. 

And, of course, consultants have been known, on the odd occasion, to overpromise and underdeliver.