The Critical First 100 Days of Onboarding — What You're Likely Overlooking That Could Make or Break Your New Hire After a new employee starts, the true "getting-to-know-you" period begins. It's crucial for both the employer and employee to make a positive impression during the first few months, as it will determine who remains with the company and who doesn't.

You probably have heard the importance of the action plans of the "first 100 days" after a new President takes office or after you begin integrating two companies after a big merger, but I am guessing you haven't heard it applied to your recruiting and onboarding efforts with each of your new staff members.

In many marriages, couples date for years before getting married. In contrast, in recruitment, someone can join your organization after only a few hours of interviews, which means you are essentially living and working together from the start of their employment.

These "first 100 days" will dictate whether this union will work or not, and how you handle these first few months is critical.

Related: Ask These 9 Interview Questions to Hire Leaders Who Deliver Real Results

What you need to do to win over the employee

This is similar to getting to know someone you're dating. As the employer, you need to be on your best behavior because the employee is deciding whether they want to stay with you for the long term. During this time, you'll want to ensure that:

1. The employee is properly welcomed

The rest of your staff needs to stop what they are doing and properly welcome the new staff member to the team. This may include taking them to lunch on their first day on the job, taking them out to happy hour in the weeks after they have started (yes, this is an ongoing welcoming process) and assigning them a "mentor" that can help them navigate the organization.

It is critical during this period that what you promised them during the recruitment phase actually materializes in their day-to-day job. So, ensure their expectations are properly set upon hiring and properly met during this welcoming period. It's difficult to alter a first impression after it's been established, so it's important not to make any early mistakes that could harm your reputation. And the last thing you want is a revolving door with talent.

Related: 5 Tips for Effectively Onboarding and Training New Hires

2. The employee is properly onboarded

Employees aren't just going to step into a role and know exactly what to do on day one. They need to be properly trained, duh!

But you would be surprised to find out how many companies don't have a formal training plan for every position they hire for. That is the equivalent of throwing the new staff member to the wolves and hoping they learn how to survive.

Before the start date, you need to have documented the full job description and key expectations of the job, including any KPIs they will be managed by, the curriculum and materials for which they will be trained to be successful in the job, and the training calendar of key people within the organization they will meet in their first weeks on the job, who are in charge of training the various aspects of the company and the role.

The more comfortable they feel with their training, the more confident and "loved" they will feel.

3. The employee is properly cultured

When working with a new staff member, they need to learn and feel the culture you are trying to promote within the organization. For example, in one of my businesses, we aspire to have a S.P.I.R.I.T. culture, where all employees strive for Service-First, Positive-Minded, Innovating, Respectful, Intrapreneurial and Team-Oriented behaviors while on the job.

You can't simply slap that on a slide in your strategy deck; you need to live those behaviors in your everyday job, and that starts from the top. If you want the new staff members to live by those rules, they must see it manifested in their interactions with the rest of the staff.

So, ensure the entire team demonstrates those desired workplace behaviors, which they naturally should be if they are "living the culture" of the organization.

Related: Building a Culture of Quality — How to Ensure Your Products, Processes and Teams Meet the Highest Standards

What the employee needs to do to attract you

This is not a one-way street; the employee needs to work with you as you work with them. In the first 100 days, you want the new employee to live up to the expectations they set during their recruitment process.

Do they really have the skills they said they have? Are they behaving in the way you want new employees to behave, culturally? Are they hitting the goals you have set for each other? If so, full steam ahead. If not, you may have a problem on your hands.

Related: 4 Ways to Boost Your Employee Retention in an Uncertain Economy

What to do if the magic wears off

If things are not going to plan after the first 100 days, you really have one of two options.

First, you feel the relationship is salvageable and there is a clear long-term path forward together, most likely with additional training. Second, you need to pull the "ripcord" and mutually decide that this isn't working out as planned, and both parties need to agree to part ways.

Hopefully, your offer letters incorporate some type of probation period language that will legally enable you to exercise these rights if things are not working out. However, you should not keep the employee if you do not see a reasonable path forward together.

Closing thoughts

Many good entrepreneurs put a lot of energy into recruiting great staff members to join the team. But many of those same entrepreneurs don't put enough energy into what to do with those same new employees once they actually get started.

That is where the "rubber really hits the road." Your long-term success, both as a hiring manager and as a company (depending on good employees), will be decided in those first 100 days after a new employee gets started. So, don't blow it. Remember that you only have one chance to make a good first impression both ways.