Design is fundamental to Product Lifecycle Management (PLM). From the initial steps in the product lifecycle, when a product is still to be realised, to the design of supply chains for product distribution, to the design of processes for the end of life, the design decision-making shapes the roadmap for PLM. Consequently, how holistically we understand and apply the various dimensions of design in decision-making will determine the PLM outcomes. Therefore, this paper introduces the COSMOS framework as a novel, holistic mapping of various dimensions of design to aid design decision-making. The paper argues that the six dimensions, namely, Cognitive, Objective, Subjective, Managerial, Operational, and Social, provide a holistic view of design and serve as a guide and checklist for designers to ensure that they have covered the key dimensions of a problem context in their design process. The paper presents the basis for arriving at these dimensions and lists some of the established factors relevant to each. The affordances of the COSMOS framework for the design process are briefly discussed, concluding with the implications for PLM.