STEM infers business logic from the connections you sketch between
the key revenue and cost entities that define your business
The scope and outline structure of a STEM model is often first sketched out at a whiteboard. You can see the iconic representation of the key elements in the software as somewhat reminiscent of that whiteboard chart. When you create connections between elements, the experience is entirely analogous to sketching connections with a dry marker on the board too.
If your business idea has three customer types, then the first thing you do is to drop three service elements into a view, either from the toolbar on the left or, more conveniently, from the new local context-menu element palette. (If your model is more ambitious or pedantic, you might start with three separate market elements too, one for each service, but that is only essential if you are considering multiple markets and service types at the same time.)
The right-click or context menu for each service accesses input dialogs such as Demand or Tariffs (i.e., pricing), where you can enter your initial assumptions such as Customer Base (which might be a constant) and Penetration (which might be an S-curve or some other explicit time-series data). You can press the Graph button on the dialog menu to preview what an S–curve looks like.
The key costs for your business might include a specific component that you need for one customer group, as well as a delivery platform which may be required by all. You can drop two resource elements into the view in the same way you created the services, and again access key assumptions from the icon menu such as the Capacity and Lifetime, Deployment and Costs.
The sense that a service requires capacity of a given resource is illustrated by a connection between the two elements, much as you would sketch a link between them on the whiteboard. Click the Connect button on the toolbar (or just click near the service icon in the forthcoming STEM 8.0) to draw a connection between the two elements. The software will prompt if there is any ambiguity over what the connection might mean, and the line subsequently drawn also features a context menu to access such options.