This thesis addresses a problem at KLM E&M, where a gap exist between the desired performance and current performance of airframe MRO. This research is performed to find solutions within the A-check for wide body aircraft by identifying the constraint in the A-check and subsequently develop solution alternatives by first exploiting the constraint, then elevating and finally develop a ‘desired world’ alternative. For the A-check a theoretical preliminary model was developed which tests Phase-Gate methodology and concentrating resources within the phases during the check. It was found that applying Phase-Gate and aligning the available manpower to the workload could improve the output performance of the A-check. The best of the designed solution alternatives all consists an implementation of a core shift, which focus of aligning and full concentration of available manpower to the workload.