Human errors are prevalent in manual assembly line statistics, but humans are still a necessary and numerous working force for assembly tasks. Since faster and shorter production cycles lead to higher mental efforts, an alternative to decrease the cognitive load and errors of manual assembly lines is using Augmented Reality (AR). AR increases system interaction and assists operators in the step-by-step of any tasks performed. Its use allows granular production data, enabling an increase in quality control and timely detection of assembly problems. However, AR alone is not enough to avoid demotivation and lack of engagement in the task, which is repetitive in nature. Gamification can become an auxiliary resource to increase operators' motivation and engagement. This work presents a system model to integrate AR and gamification for a manual assembly line called GRAAL. GRAAL was used to develop an actual systemfor Printed Circuit Board (PCB) assembly, which is able to guide operators using AR but also tracks down their efficiency and efficacy which is then used for gamifying their performance. We conclude that modeling a system that merges AR and Gamification is feasible but a non-trivial task. The system's features are dependent on conditioning factors such as Application Environment, Application Context, Application Audience, and AR hardware.