70-20-10 is a formula that describes how someone learns to do their job.
The formula, which was developed by Morgan McCall, Robert Eichinger and Michael Lombardo at the Center for Creative Leadership, proposes that on average, 70% of a person's learning at work is internal and experience-based, 20% comes from interacting with fellow employees and 10% is the result of formal training and reading.
In human resources, the 70-20-10 rule is often used to define the ideal balance for how to provide corporate learning and staff development opportunities. 70% of training should take place while on the job, 20% should be conducted informally through mentoring programs and 10% should be conducted formally through training sessions. Although learning management systems (LMSes) have traditionally been used to deliver the 10% portion of the 70-20-10 formula, some systems can now support the 20% by providing employees with the ability to collaborate and the 70% by providing employees with learning opportunities when necessity demands it, a concept called just-in-time training.