Today I learned the difference between a business process and a business procedure. I looked through a few sources on the web and found that a process is made up of many procedures and tasks, and can cross departments. A procedure is a set of instructions to complete one unit of work. I would equate these to separation of concerns in software.
Think of an enterprise application environment where there are several standard concerns such as - application access security, sending emails, logging errors, reporting on data, saving transactional data, sending data to an external destination, etc, etc. These are re-usable procedures. A process collects them into something meaningful.
Since most common concerns can be thought of as procedures. It would be helpful to think of procedures as abstractions when describing a process.
Consider a task of explaining the process to a non-technical person, or someone outside your organization. The details about the procedures are specific to your domain, also they could change without the overall process changing. Is it a process or procedure? Could it be changed without affecting the path from point A to point B? Can parts of the process be standardized or abstracted into procedures?
For a more concrete example, a procedure could be "communicate with someone". There may be some criterion that will change the communications type but the end result is communication. Perhaps the communication is an email, could be a phone call, a text, in person, etc. The point is that a communication needs to take place, and the details are not a concern of a process.
Perhaps some Protocol will define what steps to follow for the communications procedure. Perhaps the communications needs to be saved for auditing purposes. That would limit the possibilities of forms of communication. In any case, those are procedural details. The process is about linking procedures.