Manufacturers of products that are instances of variants out of a complex product portfolio have learnt that a rigid process management is mandatory to meet today's standards of quality. An important part are processes that aim at mastering variant complexity. v.control supports these by providing for the first time both a complex product model able to represent detailed engineering, manufacturing, logistics, finance and marketing data in the very same model and a workbench of provably mathematically correct and rigid analysis tools.You want to know whether product changes performed by different engineers are compatible? Press a button and v.control guarantees consistency of all product variants. You want to know whether all your products suggested by marketing can actually be build? Press a button and v.control checks your portfolio and detects problematic variants. You are searching for a product meeting partial customer requirements and being optimal in profit? Press a button and v.control provides the optimal product cash cow. You want to make sure that your product portfolio meets future environmental regulations? Press a button and v.control identifies opportunities. You want to engineer shared parts of your product line to meet manufacturing inventory requirements? Press a button and v.control designs an optimal solution. This paper presents a detailed overview of the functionality of v.control as well as typical industrial applications successfully conducted with the help of v.control. It addresses current research in the field of complexity management, variability management and SAT-solving and their functional integration within v.control.