Concept inventory questionnaires are tools which measure the conceptual understanding of students and can be used to measure the effectiveness of teaching interventions and innovations through a pre and post-test format. Using existing tools allows faculty to build upon existing research in the field, however sometimes it is necessary to adapt a questionnaire so it is suitable for the needs of students and educators. Many existing conceptual questions use filament bulbs which are now not commonly used in educational demonstration or electronics projects and so may be unfamiliar to modern student cohorts. A framework for updating concept inventories is presented with the update of an existing concept inventory (DIRECT) to “reDIRECT” used as a case study. reDIRECT was piloted with 601 participants. Test results were analysed using the statistical measures from the original paper which found reDIRECT has an average difficulty index = 0.37 (DIRECT = 0.41); average point biserial correlation = 0.34 (DIRECT = 0.32); average discrimination index = 0.29 (DIRECT = 0.23). Within the cohort differences were found in student understanding between those in the first year of a three-year BEng compared to those in the first year of a four-year BEng in all measures. The four-year BEng students study at universities in both Ireland and the UK, providing a reference point between the conceptual understanding of students at different entry points to degree programmes in engineering in each educational system.