Definition:
Management by Walking Around (MBMA) referee to a style of business management which involves manages wandering around, in an unstructured manner, through the workplace at random to check with employees on the status of ongoing work. The origin of the term has been traced to executives at the company Hewlett Packard for management practices in the 1970s.
The emphasis is on the word walking as an unplanned visit, when employees are not expecting a visit from managers at a more systematic, pre-approved scheduled time. The expected benefit is that by random sampling of event or employees discussions, is more likely to facilitate improvements to the morale, sense of organisational purpose, productivity and total quality management.
Further Reading:
Book: SUCCEEDING WITH AGILE Software Development Using Scrum by Mike Cohn