When I order something at Amazon, my order could be shipped from three separate places with even third-party shippers being involved, possibly.
To me, ordering the products and me receiving them at my door is the "Process." A third-party shipper receiving the order for shipping something to me electronically possibly kicks off an internal "workflow" that involves printing a pick list, people walking up and down aisles of products, picking the items in the picklist and placing it in the basket, the basket reaching somebody who packs these items in a box. This person may pack the box, slap a shipping label on it and leave it at the place where possibly UPS or Fedex picks it up for delivery. Now, that’s a workflow.
From both Amazon’s point of view as well as my own, the time taken from the time they receive the order electronically till the time it is ready for shipping may be of interest from a "Process" point of view. Of course, the third-party shipper may need to monitor every step of the "workflow" to improve operations.
The same principle applies if you consider mortagage loan processing. Loan application filling up, credit verification, house appraisal, employment verification, underwriting, funding and loan close could all be process steps. However house appraisal may be a workflow in its own right, possibly involving thrid-party appraisers on contract.
When you see any process documentation, you see pages and pages of Visio diagrams really describing the workflow. It may be worthwhile abstracting these workflows into process steps.
Measurement and reporting are quite often meaningless if you collect performance data of every workflow step. There will simply be too much data for any information to be gathered out of it.
It pays to keep processes separate from workflows! They make understanding, monitoring, measurement and reporting sane and meaningful.
Too often, the energy and creativity of improvement teams isn’t focused on macro or cross-functional processes that really matter to the organization. This can lead to unproductive "busy work." Teams may even be working on micro processes that wouldn’t exist if the macro process was reengineered.
– from Jim Clemmer’s article, "Process Reengineering and Improvement"