Business within the company

HR departments are described as a “business within the company”.  In terms of responsibilities, what are the three “product lines” associated with HR Departments?

Traditionally, human resource management practices were developed and administered by the company’s HR department.  Line managers are now playing a major role in developing and implementing HRM practices.  Is this a good a move by businesses or should HR Managers/specialists handle HRM practices like hiring, layoffs, disciplinary actions, training, etc.?  Why or why not?