Plagiarism often occurs unintentionally due to unfamiliarity and lack of knowledge about the academic way of writing. Only when plagiarism is done deliberately and with the intent to mislead about your knowledge is it considered as cheating.
When a student is suspected of having plagiarized the case may be handed over to the disciplinary board. If it turns out that the student has plagiarized deliberately with the intent to mislead about his knowledge the board can decide on warning or suspension from studies for up to 6 months (Higher Education Act SFS 1993:100, 10 chapt. 1 and 2 §§).
A student who reuses his own work or group work from an earlier course without mentioning this can be reported for misleading. Students also risk disciplinary measures if they participate in group work and somebody in the group has plagiarized with the intent to mislead about his knowledge. In that case everyone in the group will become the object of investigation regarding their responsibility.