While it is common practice in the consulting industry to prescribe solutions before diagnosing the problem, in every other profession this would automatically create a huge liability and be seen as malpractice.
The best example is to look at doctors. If your doctor omits to take an appropriate action, or gives you a treatment that causes harm, injury, or kills you, they committed medical malpractice. It is understood as a medical error, and they are liable no matter what.
When we look at consulting services, however, the picture changes. I see consultants proposing solutions and pitching their services right off the bat, sometimes on the very first call.
Both sides have some share of the blame here. Consultants who have a poor sales process or experience do this, but prospects are also guilty of trying to impose such a process upon us. However, would a doctor prescribe a treatment without diagnosis just because the patient asked for it?
We owe it to ourselves and our clients to never propose solutions to a problem we haven't fully explored. This is how professional consultants act. And this is how the prospect will begin to look at you as a competent and reliable advisor.
When I share this idea with consultants that sell implementation services (such as freelancers or agency founders), almost all of them counter with the same objections: "prospects don't have the time." With all the respect, that's an excuse.
It is true that in a buying process where a company contacts multiple consultants and asks each other to present solutions, the prospect will not have the time to invest in diagnostics with all of them. That's exactly the reason why he jumps the diagnostic phase, controls the process, and decides his self-diagnosis is enough to proceed.
But how many times have we moved forward with the client's self-diagnosis only to discover it was wrong? That the company stated their problem was X, while in the middle of the engagement we found out what they really needed was Y?
Chances are the prospect's self-diagnosis is wrong, or at least biased and incomplete. Doctors know the same of their patients. Lawyers and accountants know the same of their clients.
If you want clients to see you as a trusted adviser, you will need to reject their bad ideas. Skipping the diagnosis phase is one of them.
When a prospect comes to you self-diagnosed, you must act just like a doctor hearing his patient ask for a specific medicine before sharing the symptoms. You reply with, "Maybe you're right, but let's find out for sure."