Finding the perfect job for a senior ExECUTIVE the position may take months of research and interviewing—but that's only half the battle.

Without an effective onboarding strategyyou may end up repeating your search in 12-18 months. Whether you let them go for failing to hit their target or leave out of frustration, the result is the same.

When this happens, you've not only wasted time and effort, but you've also wasted a significant portion of your budget. Gallup research shows that replacing them costs half to twice the salary of an employee — and the salary of a senior executive is considerable.

Their removal also leaves a hole in yours management structure which can affect team morale and productivity.

Hiring and retaining senior executives therefore requires a flexible onboarding process that strategically integrates them into their new roles and the company as a whole.

Related: How to create a strategic hiring plan

1. Start before their first day

Waiting for new hires to “hit the ground running” doesn't make much sense. Why would you want them to run before they know where the goal line is? They may end up going in the wrong direction.

It is much more effective to give them a map of the territory and let them get under it. Prepare all the information you will need and have it ready before they walk in the door for the first time: key stakeholder names, organizational chartsa background on their department and team, etc.

That doesn't mean you have to throw everything at the new executive at once. To avoid overwhelming them, introduce the information gradually over the first two or three weeks.

You can also start adding essential activities to their calendar before the first day. Significant engagements may include meetings with board members, executive teams and subordinates. Team or one-on-one lunches are a great way for them to get to know their direct reports and other members of the leadership team – and all the local lunch spots.

Related: How to breathe new life into your formal entry process

2. Set clear expectations from the start

When bringing in a senior executive, carefully evaluate their experience and determine which strategies align with your company's culture. They may be eager to bring what they know to your table, but respectfully reject it up front if they propose an approach that isn't a good fit.

Similarly, develop a 30-, 60-, or 90-day plan with the new executive to create realistic goals and create a definition of success. This gives them a target to shoot for and allows you to determine where they may need additional training.

Be careful not to make this plan seem punitive. Be clear that the goal is to align them with the long-term vision of the leadership team. They need to understand that this is a way to ensure success, not to punish failure.

Related: 5 ways to keep your vision and mission intact as your team grows

3. Foster a supportive environment

Success thrives in supportive environments, but what does a “supportive environment” look like for a newly hired senior executive? There is no magic formula, but some elements can be assigning them a mentor or coach, creating opportunities for feedback and open communicationand planning regular synchronization with the management team.

Mentors fulfill a different role for executive-level employees than for entry-level employees. At the entry level, mentors help employees adjust to the overall corporate culture, learn new skills, teach them how to network, etc. and processes.

Communication is the foundation of a supportive environment. It helps build trust and rapport. Unfortunately, many businesses struggle with keeping the lines of communication open, especially at scale. They turn to bots and software automation to help bridge the gap, but that can feel faceless and impersonal.

Nothing replaces regular meetings and informal gatherings to allow new leaders to engage in frank discussions about roles, expectations and team dynamics. Maintaining constant communication and regular synchronization with the leadership team go hand in hand.

One-on-one meetings create opportunities for open dialogue, allowing new leaders to discuss their progress, challenges and ideas. These checks help the flow of communication and strengthen team relationships, and they also provide opportunities for course corrections, if necessary.

4. Build a flexible runway

Entry programs are not “one size fits all”. Everyone adjusts at their own pace and some need a little more runway than others. Some settle into their new role after a few months, while others may take up to a year. Not that the latter is wrong for the role; there could be a number of reasons why they need a bit more.

For example, if they've moved for the role, they're not alone adjusting to a new job and company culture. They are also adjusting to a new city, a new home, new schools for their children, new health care providers, etc. However, given time to work things out, they can become one of the strongest leaders in the company.

As part of your onboarding track, make ongoing leadership development programs available. Even senior executives seek opportunities for personal and professional growth within the company. In turn, they may be able to draw from their well of experience to augment your leadership training efforts.