The marketplace is speeding up, and the world is more complex than ever. The organizations that don’t adapt don’t survive. But what sets successful companies apart from those left in the dust? Companies that transform their businesses, shift their cultures and execute on new strategies have senior leaders who model those changes. These leaders don’t just talk the talk but walk the walk. They aren’t afraid to get their hands dirty.

Sounds easy enough, right? Businesses should transform their cultures as quickly as a NASCAR pit crew changes four tires. But that’s not reality. Culture change does not happen overnight, because changing behavior is hard. It takes time and energy – which senior leaders have in short supply.

Senior leaders have competing priorities and pressures. It’s often easier to forgo their own development than carve out the time for it. It’s easier to delegate culture change than to lead it themselves. There may not be a strong incentive to invest the energy required to practice new behaviors, and our organizations’ systems are built to encourage stability and the status quo. Without engaged senior leaders, even the best-intentioned change efforts fall flat.

Modeling is one of the most powerful tools in the leadership toolbox. The idea is simple: If you want others to do something, you must do it first. It works in parenting, it works in school and it works in leadership. Want to build a more innovative culture? Want to encouraging exploration, experimentation and failing fast? Then senior leaders must explore, experiment and fail fast.

It would be so much easier if organizations could change from the bottom up or even from the middle, but organizations don’t work that way. Most organizations are driven from the top down, with senior leaders at the controls. They determine if a culture moves, which makes them the real change-makers.

The most successful culture changes happen when HR spends a significant amount of time with senior leaders first, helping them get and stay aligned. This means hitting the “pause” button on making announcements to the organization or printing signage or kicking things out to the field. Instead, invest the time to ensure that senior leaders have the will and skill to model the new behaviors required by the strategy and by the culture you want to create. If you don’t move the senior leaders, you don’t move the organization.

Take a cascade approach. Start with the senior leaders, then work with their direct reports, then on the next level and so on. You don’t have to influence everyone in an organization; if you can get the senior leaders and key influencers on board, they will bring everyone else along.

Here’s how to make modeling work:

1. Talk about the outcomes you want and the behaviors that will get you there. For example, let’s say you want the team to be more innovative. Tell them, “I’d like us to be more innovative,” and describe what that performance looks like (developing new products, implementing new processes, creating more value for customers, etc.). Then, describe the behavior you want, such as experimenting with new materials, trying new processes, asking “why” and being curious about how others are approaching problems.

2. Act on the behavior. For example, if you want others to ask “why,” you must ask “why.” Be obvious about your behavior so others notice; be blunt. Ask, “What new materials have we tried today?” or, “What’s something you’ve tried that’s new?” Modeling does not require subtlety; it requires being obvious.

3. Ask others to recognize when you act on the behavior and call you out when you don’t. They will keep you accountable to the commitment you made and call attention to the behavior you want to encourage.

Modeling works best when you make a new behavior obvious, then act on that behavior again and again and again. For better or worse, the most important thing you can do is to show others how you want them to behave. As leaders, we are always on stage, and if we want to make any change in our organizations, that change always starts with us.