The European Union's (EU) General Data Protection Regulation (GDPR) makes it illegal to collect, process, and store personal data unless it is done in accordance with the prescribed legal and regulatory clauses enshrined in the Act. Organisations face significant challenges in navigating GDPR requirements and assessing their level of compliance. In particular, failure to comply with GDPR may potentially expose the data Controller and Processor to steep legal penalties including possibly administrative fines of up to 20 000 000 EUR, or in the case of an undertaking, up to 4% of the total worldwide annual turnover of the preceding financial year, which is imposed by the Supervisory Authority. This paper presents the results of a minimum viable product, the GDPR Compliance Assessment Toolkit (GCAT). The main objective of the GCAT is to assist organisations to assess their current state of compliance to GDPR. Drawing from an experimental research and development approach, GCAT is then compared with other existing GDPR compliance assessment technologies. Comparative analysis results shows that GCAT simplifies and optimize GDPR compliance assessments.