In order to increase the level of efficiency and automation, we propose a conceptual model and corresponding tool support to plan and manage the systematic evolution of softwareintensive systems, in particular software product lines (SPL). We support planning on a high abstraction level using decision-making concepts like goals, options, criteria, and rationale. We extend earlier work by broadening the scope in two dimensions: 1) in time, supporting continuous planning over long periods of time and many releases, and 2) in space, supporting traces from high-level decisions down to the implementation. We present a metamodel which allows to represent these concepts, corresponding prototypical tool support, and a first example case using data extracted from an open-source project, Eclipse SWT.