What work path do there exist to identify reasonable vertical slices of a classic n-tier platform code base and infrastructure (enterprise size)? Regardles of refactor or a new solution I think there will be the same approach (more or less?) So i'm primary interested in steps and definitioning of modules, functions, then test them into a function-unit or if it's appproved as a vertical.To extend my thoughs..I understand that a vertical should be a actor, a kind of business value. But is a communication system a actor, or a functional unit in a vertical slice? Probably yes And no (depends on enterprise), but how to decide? Is shipment a part of Order, or are both Order and Shipment different verticals? What should a vertical slice consist of, to be a true vertical? In terms of Levels of functions, like an own data store, an own client configuration tool, an own business intelligence calculation and so on. Btw: It's a requirement that the verticals should be deployed and operatable independently of each other.Maybe there is a kind of yes/no schema to use? Is this X used for Y? Yes - then it's a vertical. Is this X used with Z? - Yes, then it's anti-pattern for vertical. Is X depend on the funtion YY? If yes, then.. And so on. Links to success stories when define verticals is also of interest. 
Best practice refactor n-tier into vertical slices architecture
architecture;refactoring;enterprise architecture