Discussion on:

Five tips for handling stubborn clients

I have come across very similar situations in the projects I work on. Go back to the original project plan and see if it needs to be revised to take into account the new information that you have uncovered during the project. Oh wait! Was there a project plan ever written?
if not put one together and present it to the technical lead and ask their opinion? If it is good they may very well present it to their boss as though it was their idea. Either way the result is that the correct implementation is done and the technical lead looks like a hero.

One approach I've found helpful might be seen as "between" 4 and 5 - Go back to the drawing board (communicate a better solution more persuasively) by Going out to the masses, but with the twist of the "masses" being other folks who have solved a similar problem. By finding and showing the stubborn client examples of others "like them" who have solved a similar problem, you
a) Keep your persuasion points positive and focused on their success
b) Eliminate the "my solution vs. your solution" confrontation
c) Help them lower fear of risk by hearing other's success stories (you can also try
fear-of-failure stories, but for some reason it's harder to find supporting blogs/white papers about failures, and citing only your own opinion, well... see point b.)
d) Demonstrate a honest effort to solve the problem (like ptailor129 suggests.)

Even if this client fails to "do the right thing", you gain knowledge for the next round by performing at least a quick review of other's solutions....and who knows, while digging, you might even discover something better which neither of you considered.

Isn't what an IT Consultant is "selling" their expertise, as well as their labor? If the client chooses to ignore your expertise after due cautions and conversations, shouldn't you walk away if they refuse to use it? An electrician, for example, if they are ethical, wouldn't just use that random bare wire you gave them to run power to your building, just because you said they must. But, I suppose they might be willing to choose between a cheaper (but relatively safe) circuit breaker box and their "ideal" one.

While I understand that clients generally own the product of our work, isn't there a limit, ethically and for the good of the field, to what you should be willing to do? And doesn't agreeing to do low standard work because the client mandated it inherently risk a consultant's reputation?

I'm trying to walk this tightrope, too... and BTW, I've done all 5 + #7 in the comments

This seems like a great way to present an arguement for why to implement something a specific way, but I've always had trouble with it in the past, aside from lengthy white papers, or the inevitable 'at this other client...' line. Great idea, I just personally have had trouble using it!

One trick I've learned is simple, and works, is a basic pros, cons, and cost analysis. If you can quickly outline the pros (and cons) of both approaches, being objective, and then associate the cost with loss, it can be a cheap trick to close the deal, and get it done right.

My first instinct would be to document the issue(s).. using Google/similar to find similar problems and/or explanations and showing the pitfalls of the stubborn client's approach.. then I would ask the client to help me resolve those issues to his/her benefit.. I do realize this is frequently a lose-lose situation for the consultant, if you're confrontational you lose the client, if you're not, you botch the job and eventually lose the client and your reputation. Don't be stubborn yourself but try and lead the client around to your solution, framing it as in the client's best interest (which it certainly should be anyway).

Listen to what they want and make yourself heard. Try negotiation. Give a little take a little.