Increasing demands imposed on software-intensive systems will require more rigorous engineering and management of software artifacts and processes. Software product line engineering allows for the effective reuse of software artifacts based on the pro-active organization of similar artifacts according to similarities and variances. Software processes – although also variable across projects – are still not managed in a similar systematic way. This paper motivates the need for Software Process Lines similar to Product Lines. As a result of such organization, processes within an organization could be organized according to similarities and differences, allowing for better tailoring to specific project needs (corresponds to application engineering in product lines). The vision of SPPL (integrated product and process line) engineering is presented, where suitable artifacts and processes can be chosen based on a set of product & process requirements and project constraints. The paper concludes with some resulting challenges for research, practice, and teaching.