Additive manufacturing (AM) enables designers to exploit new design windows enabled by the layer-by-layer build process to create new generations of previously unobtainable products with complex geometries and internal features. Despite the promises about AM, industrialisation of the process is still challenging because the process is inconsistent and the fabricated parts may not meet design requirements in terms of dimensional accuracy and mechanical performance. Furthermore, AM is the first step in a sequence of post-processes such as heat treatment and surface finishing. Challenges due to variabilities introduced by such post-processes could influence the original CAD design, and so design compensations are often needed to achieve the final net shape product in the entire AM and post-processes workflow. In this talk, I will describe our research work on the development of design and multi-scale modelling and simulation methods, in which we study the relationships between geometry, process, material microstructure and mechanical properties of the metal powder bed fusion process. Our perspectives on the design for AM process workflow will also be discussed.