Context: At the core of choosing what features and level of quality to realize, and thus offer a market or customer, rests on the ability to take decisions. Decision-making is complicated by heterogeneous understanding of issues such as priority, implication of realization, and interpretations of strategy as pertaining to the short- and long-term development of software intensive systems. The complexity is further compounded by the amount of decision support material that has to be taken into account and the sheer volume of possible alternatives that have to be triaged and prioritized, thousands, or even tens of thousands of requirements can be the reality facing industry. There is a need to develop the functionality that is strategically most important while satisfying customers and being competitive, cost efficient, and minimizing risk. In order to achieve a balance between these factors, it is important that within an organization, all stakeholders agree on the strategic aspects to be considered and their corresponding relative importance. Objective: The objective of this thesis is to provide strategic decision-making support for product management of software intensive products. Method: A number of empirical studies, set in both academia and industry have been performed. The research methods used span from systematic reviews, case studies to experiments, all aligned to identify possibilities for improvement, devise solutions, and validate these solutions in several steps. Result: The methods presented in this thesis can be used to evaluate strategic alignment and identify possible root causes for misalignments. To strengthen strategic alignment, the methods and results in the thesis can be used by product managers for making effective and efficient strategic decisions regarding portfolios and products, following a systematic and aligned process. Conclusions: The area of product management in the context of market-driven software intensive product development is a field with unique challenges. The specifics of the solutions are based on industry case studies performed to gauge state of the art as well as map the main challenges. The decision-making support developed takes the form of models and methods that support software product management in strategic alignment, requirements triage and portfolio level decisions.