Grids are very complex and volatile infrastructures that exhibit parallel and distributed characteristics. To harness their complexity as well as the increasing intricacy of scientific applications, modern software engineering practices are needed. As of today, two major programming models dominate: software component models that are mainly based on a spatial composition and service oriented models with their associated workflow languages promoting a temporal composition. This paper tends to unify these two forms of composition into a coherent spatio-temporal software component model while keeping their benefits. To attest the validity of the proposed approach, we describe how the Grid Component model, as defined by the CoreGRID Network of Excellence, and the Askalon-AGWL workflow language have been adapted.