For larger documents like diploma thesis, master thesis or dissertation scrartcl is usually not ideal. For such works you usually need not only sections and subsections, but also chapters. Chapters automatically start a new page. Therefore in these cases you should replace scrartcl with scrreprt or even scrbook. With both classes \chapter{...} is then available as a parent outline level chapter above the section \section{...} already known from scrartcl. scrbook and scrreprt differ primarily in the default options. In addition, scrbook also provides a subdivision into front matter (see \frontmatter), main matter (see \mainmatter) and end matter (see \backmatter).
By the way, it is a common misconception that scrartcl does not provide parts, i.e. \part. Unlike scrbook and scrreprt, however, scrartcl does not create a separate (double) page for \part.