Customization involves fit and alterability and is based on understanding the commonality and variability (c/v) across industries, geographies, customers, and systems. This paper argues for an emphasis on c/v through a customization life cycle, from engineering customizable assets, components, and solutions to supporting their effective deployment. Examples of systems that focus on customization through c/v are given. These examples are described using the customization life cycle and show what mechanisms are most useful in each phase.