This thesis work has been carried out at the company Saab AB Aeronautics, which manufactures the military aircraft Gripen E. Today, the company uses 3D work instructions for assembly of Gripen E, which is displayed on a computer screen for the shop floor workers. The company has an interest in investigating whether today's work instructions can be visualized in an Augmented Reality interface by reusing available data. This work has been limited to studying wire harness assembly, which is a main part of the final assembly. The methodology case study in combination with the method Requirements Engineering has been used to analyze the company's possibilities. Data collection has been conducted with internal interviews, studying internal materials and internal courses. The result chapter contains two parts, where the first part presents a situation analysis of how today's work instructions are created in the software DELMIA and what data that is needed. The second part presents a requirements specification for an Augmented Reality Work Instruction for assembly of Gripen E. In the discussion, the situation analysis is compared with the requirements to answer which data that could be reused for creating Augmented Reality Work Instructions and what challenges that may arise. This study shows that the company has prerequisites for creating work instructions in Augmented Reality, as there is available data containing 3D models structured according to an assembly sequence with associated descriptive information.