In a nutshell a project has a beginning and an end and delivers something specific. A project cannot go on and on forever although that does not mean that a project can’t take a long time to finish.
In my experience many continuous activities can be broken down into discreet projects and are very likely more easily and effectively managed that way. However some activities are clearly continuous and should be managed as an ongoing process rather than a series of projects. For example serving coffee in a restaurant is an ongoing process. It may have many steps that are strung together and probably go on in an infinite loop or at least a number of loops.
There are those who will argue that making a cup of coffee is a project. And this is where the argument starts to get ugly. The Project Management Institute only defines projects versus non-projects as temporary versus non-temporary activities.
I think it should go a little further than that. The PMI standard needs to apply to everyone so I understand why they cannot be entirely specific. However in your particular business you need to define when an activity becomes so small that it is just a task or if it is a step in a much bigger process.
Be careful here and don’t fall into the trap of making your definition vague because then it will be difficult to categorize activities in separate buckets of projects versus others and all the resources, money and people that have to be allocated to them. Be as specific as you can. For example you could say that a project can only be considered that if it requires more than 40 man hours to complete. Anything below that it is just a task.
Another thing you have to be careful about is that your definition of task versus project is not a loophole for people to propose a string of tasks separately to get approval for their pet project. That’s just a disguise and can really drain resources at your organization if you’re not paying attention.