It’s a huge conflict of interest. Consulting firms are hired to bring tools into a business that the business doesn’t have or can’t afford normally. They bring experience and skillsets that enable real change and shine light on issues in the company that sometimes can’t be seen by anyone but an outside party.
They also bring the ability to tell it like it is without fear of reprisal, because they are an outside agent hired to come in and do a job.
In procurement and management consulting, we typically come into a business, assess a situation, make recommendations and help manage the change associated with that process. As a consultant hired by a customer, your duty becomes to the customer first.
Lately, we’ve been running into procurement “consultants” who come into a company to make an assessment, and part of their “fix” is to sell some of the product that the customer uses “because they can secure a better price based on their volume of use” or somesuch.