What is the difference between Human Capital Management (HCM) and Workforce management (WFM) ?

In one respect, in general sometimes or others at a very high or strategic level, the two can be synonymous.    However, the two, depending on how the senior leadership, and if brought in, management consultants, may approach such an issue.  HCM classically views employees as assets.  WFM is more a management systems than business philosophy.  HCM is a way to look at the "soft side" of an organization, i.e. its people.  WFM seeks to understand how to better some metric, say productivity, and thus how/where to streamline/modernize, or perhaps re-organize.  Similarly, though to exclusive to WFM, a systems implementation of some kind may be needed.

I think it is important to note that once a HCM strategy is implemented WFM is a natural by product.  IF one attempts to implement change without looking at HCM and simply provide some type of change to the organization that doesn't fit either the people, the goals, the mission statement, etc. the WFM implementation will prove counterproductive.