The Roto-Rooter man was standing on the downhill side of the overflowing sewer access plug in front of our condo. He thought nothing of being in the flow and dropping his tools at his feet. I thought a lot about it. Eeww!

Many years ago, my soon-to-be-husband asked for a hammer to pound in a protruding nail the first time we visited my parents’ house together. That nail had been there forever. We were a family of seven and it had never occurred to any of us to do something about that nail. And it’s not like we didn’t know it was there. I remember winding the cord around it while talking on the phone as a teenager. (A cord? Yeah, a cord. If you don’t know what I’m talking about, ask your parents – maybe your grandparents!)

Six months into a new job, I looked forward to a performance review because I had nothing but praise for one of my employees. When I arrived, he had been notorious for leaving bodies in his wake. He communicated poorly, had no patience for mistakes, and never bothered to understand the predicament, needs, and efforts of others. Tears were common. But that was then. Now, after six months of frank feedback and concrete suggestions, the difference was wonderful and unmistakable.

But when I told him how far he had come, his eyes welled up and he listed all the things he had not been able to do, learn, and accomplish – all technical, of course. That was where his interests and attention lay. His definition of success and mine could not have been further apart.

I tell you these stories to demonstrate simple, but consequential, differences in our sensibilities that interfere with the way we treat each other and prevent us from seeing eye to eye.

The Roto-Rooter man deals with sewage all day long. If he worried about keeping his boots and tools clean, he’d never get his job done. His experience and methods are foreign to many of us and that difference can’t help but change what he knows, sees, and values. But I know people who would be unable to treat him with respect and value his opinions just because he stands in sewage.

My husband saw the nail. It jumped right out at him as something that needed fixing. It was an obvious hazard. He couldn’t ignore it.

My family saw the nail as normal. A quirk of our house. We didn’t see it as something that needed fixing.

He could have concluded that we were careless slobs. My family probably concluded that he was preoccupied with mundane details – clearly not an intellectual. My respect for him transformed that old familiar nail and taught me an unforgettable lesson about how two people don’t see the same thing even when looking right at it. Similar lessons followed: Where he saw a lawn that needed cutting, I saw a place to toss a ball around. Where he saw a car that needed washing, I saw a car. Where he saw a dinner that needed cooking – it would be fun to continue with this list, but I think you get it by now!

My employee and I both learned an important lesson the day of his review. How you measure success matters! You can talk about goals and metrics and methods and behaviors until you are blue in the face, but you will never be on the same page if you fundamentally measure success in different ways.

I often help clients make complex decisions. The groups I work with can be extremely contentious and quite dysfunctional. More often, they are only as varied as a Roto-Rooter man, a craftsman, an elitist or two, and the guy who routinely leaves coworkers in tears. Invisible differences, coupled with historic baggage, make every group more complicated than first meets the eye.

My challenge is to get them working together to create and commit to a shared vision. And to do it fast.

So how do I lead complicated groups to enthusiastic decisions in remarkably little time?

My secret is clarity. That should be no surprise given that creating clarity is what I’m known for. But let me tell you how this works.

1. Generate agreement about the current state.

People rarely agree on how things stand today. On the surface, yes, but once you start digging, you find the nails that drive one person crazy but are invisible to everyone else. You find tear makers who are respected for their courage, or at least forgiven due to their technical expertise. You find those who stand in sewage, which somehow makes their opinions less important.

Despite these discrepancies, you must arrive at some agreement about where things stand and whether change is important. Be specific and ask for evidence. It is the assumptions people make about the facts that create division. Find the facts.

Skip this step and it will come back to bite you over and over again.

2. Establish shared objectives.

Once you agree on the current state and a need for change, define a future state everyone can get behind.

3. Maintain a firewall between the desired future and the transition required to get there.

Transitions can create havoc. They can be costly. If you let people dwell on transition issues while envisioning a new future, they will be paralyzed by doubt and fear.

4. Establish a clear process that will get you from the current to your desired state.

The process must come before content. Identify the tangible intermediate outcomes necessary to success and base your process on achieving them.

5. Tackle one step at a time.

Focus. Don’t conflate multiple steps. Now, the future, and the transition are all distinct. Keep them that way.

6. Address disagreement by backing up and determining where things went wrong.

When you run into trouble, it’s often because you short-charged an earlier step. Debating alternatives before agreeing on objectives is a super common example.

7. Clarify roles.

Another way groups get into trouble is by failing to clarify roles. Is the group making a decision, making a recommendation, or providing input? Does each person know why they’ve been included? Do they know what hat(s) you are expecting them to wear?

If you want to lead a group to a strong agreement—the kind of agreement that generates commitment and energy—you need to create clarity of purpose, process, and roles each step of the way.

This article first appeared on Forbes, May 29th, 2018.