Flow is the movement of resources in the system.

Ex. Inventory coming in or shipping out, revenue coming in vs cash being paid out, tweets and threads added to the queue vs posts published

Inflow refers to resources moving into the system. Outflow refers to resources moving out of the system.

As a digital writer, my inflow is the number of publishable pieces I write per week. My outflow is the number of pieces I publish.

Stock are "holding tanks" where resources pool together.

Ex. Bank accounts that pool business funds, warehouses that store inventory, a database or spreadsheet with content to be published

For digital writers, the stock is in a few places: idea storage, drafts storage, scheduled posts.

Slack refers to how much reserve stock you have.

Ex. Cash balance, inventory levels, number of posts scheduled to be published

It's tempting to accumulate a ton of reserve. But slack must follow The Goldilocks Rule: not too much and not too little.

As an online creator, having too many ideas and drafts stored means you need time and energy to organize and switch between them. But too little ideas, drafts, or posts ready to go leads to anxiety or if life happens, your entire business grinding to a halt.

Start assessing your work from the lens of systems and subsystems. When you do, you begin transitioning from being an artist to a business owner.

Looking to upgrade your understanding of systems? I highly recommend reading Thinking in Systems by Donella Meadows.