Resumen
An existing, rapidly evolving strategy for realizing requirements in product line development is described. The position taken and the proposed new directions are based on our substantial experience in building and using O-O frameworks. Important new directions include the use of hooks to encapsulate product-line requirements and the management of requirements using a hook evolution model and experience base construction. It is also proposed that requirements traceability can be supported in an obvious manner by following prescribed processes for product development that are based on enacting hooks.