This tutorial shows how to create a Lean-Case SaaS B2B model with a Get-Customer-Phase modelling the Sales Process of converting prospects into customers and a Keep-and-Grow-Customer-Phase modelling the Account Management Process. You learn how to set up all revenue streams across those two phases, connect the streams with conversion rules and validating the mechanics of your model. We are also showing you how to add all elements to calculate your unit economices - churn, cost of goods sold and cost of selling. Finally, we provide an example how to add organizational units to your model with jobs, groups, team roles and manager roles. Headcounts can be automatically calculated driven by the number of sales teams, customer quotas or revenues. After learning these basics, you can get started to adjust your model.