The results are in. Recent reports confirm what most successful business leaders have known for decades: Assembling and retaining a diverse and inclusive workforce is essential for business in the 21st century.

A strong employee retention strategy focused on diversity, coupled with a customer base that celebrates a company’s inclusive values, can improve brand affinity — and the bottom line. "Basic economic theory suggests that consumers will correct for a company’s lack of diversity by simply not spending money there … The same can be said of employees, who are constantly balancing the costs of working somewhere against the personal benefits they derive, including a match in values," according to a report in Forbes Magazine.

As companies build workforces that reflect their customers and the world in which they live and work, the most profitable ones are going beyond recruiting diverse employees. They are taking steps to create workplace cultures that celebrate difference, encourage inclusiveness and maximize the proven benefits of having staffs with multiple backgrounds, perspectives, personalities and skills at all levels.

How can your company create a diverse work culture that thrives? Here are five tips gathered from CEOs, business publications and diversity experts to help companies make their Diversity and Inclusion (D&I) programs meaningful.

1. Taking it from the top

Boris Groysberg and Katherine Connolly from the Harvard Business School talked with 24 CEOs of companies known for their strong diversity and inclusion programs to learn their secrets.

They found that the CEOs "did not see diversity as a once-and-done initiative, nor did they hand off the responsibility for it to others. Rather, each of the 24, in his or her own way, approached inclusivity as a personal mission."

CEOs can show the company’s commitment to D&I by involving themselves directly in activities such as special events, mentoring, networking groups and diversity committees. More importantly, they should strongly consider appointing women and minorities to top positions, and holding managers accountable for monitoring and retaining diversity and inclusion in their departments.

For example, CEO Randall Stephenson, one of the 24 business leaders interviewed by Groysberg and Connolly says that AT&T benchmarks "diversity objectives at the senior levels of management, and we have regular meetings around my table about how we’re advancing … A portion of our officers' compensation is based on achieving those objectives."

2. Diversity is in the data

Many CEOs have instituted surveys that measure employees’ perceptions of the company’s D&I programs. They also maintain data that keeps track of their retention of minority employees and their career trajectories. At Bank of America, CEO Brian Moynihan, also one of the 24 in the Harvard Business Review report, says the company has "built a diversity-and-inclusion index that tells us if people here feel they are treated fairly and to help us ensure that people of diverse backgrounds can succeed at Bank of America. With this data, each team can have a dialogue to determine what we’re doing well and what we can improve to make Bank of America a better place to work."

3. Flexibility for all

Be sure to communicate to employees that your company is willing to accommodate the observance of religious holidays, cultural celebrations and clothing restrictions, as long as such attire is professionally appropriate. Equally important is for companies to provide benefits such as daycare, childcare subsidies, flexible schedules, job-sharing and telecommuting options as long as they do not compromise workplace productivity.

4. Equal opportunity programs pay off

In Groysberg and Connolly’s CEO interview, MasterCard’s Ajay Banga noted, "We have women’s leadership networks, a YoPro group for young professionals, a group for employees of African descent, a pride community, a Latino community, and an 'East' community for Asian employees. Each BRG [business resource group] has a business sponsor, who’s normally a direct report of mine. We do a ton of things with them, from employee-networking events to multicultural summits to a women’s forum for which we get outside speakers as well as panels comprised of me and members of my board." While such programs are expensive, many CEOs see them as crucial to building a strong company culture—and well worth the investment.

5. Partner power

As diversity and inclusion expert Joe Gerstandt points out, successful diversity and inclusion programs really comes down to creating workplaces where employees feel free to be their authentic selves. "… inclusion should be about the inclusion of authentic, true, whole people who are naturally going to be different from each other. We can’t just hire people who are different from each other; we have to allow them to actually be different at work."