This paper aims to investigate the effectiveness of automatic grading systems, with a focus on their uses within Computer Science. Automatic grading systems have seen a rise in popularity in recent years with publications concerning automatic grading systems usually linked to a specific system. This paper will discuss the factors that need to be considered when using automatic grading, regardless of which system is being used, and will make recommendations for each factor. This discussion is based on the authors' experience of using an automatic grading system in a CS1 environment. From the research conducted, many elements should be considered when using these systems. These include how the code will be tested, the need for plagiarism checks and how marks are awarded. The findings of this study suggest there is a lack of defined standards when using these systems. This analysis of the considerations provides valuable insight into how these systems should be used and what the standards should be built on.