Real-Time Critical Systems are pervasive in human nature. Thus, this thesis outlines the main facts encompassing critical system design and perserverance towards decisiveness. In essence, every decision made through the project has had a shadowed theory or method, or fact outlining the directed concept. Addressing a case study that illustrates factual concepts and real-life experience regarding Ada and SPARK projects. Moreover, it outlines background, as well as research that aids on decision making, elaborating the project's purpose. Additionally, the project follows a drastic approach towards building up the foundations that allows a HRM prototype to be programmed in Ada and an incremental development towards the success of the system. Foremost importance of the thesis was to prove that Ada and Spark is essential to critical systems across the globe and allow people with similar interests to follow well-structured tutorials to implement the project. As a result, you will have designed a fully functional HRM and have learnt fundamental concepts essential in Computer Science, Software Engineering and Circuit Design, as well as how to apply them to a project in a real world scenario. Highlights: You get to design a Heart Rate Monitor... Amazing!