Do the math
There are many costs of turnover including replacement, disruption and stress to remaining employees, diminished morale and other turnovers, and loss of competitiveness. Turnover costs are mostly commonly estimated at 1.5 times an employee's salary.
When you add those costs up in your organization, a small investment in providing employees with what is expected of them in their job (competency model), and their ability to control how quickly they can meet those expectations (competency assessment and personalized learning), it’s a clear net ROI. Download a business case template.