In this paper, the main aim is to propose an engineering process management for enhancement of in-building Radio Frequency (RF) coverage of mobile networks for customers. Mobile service providers are currently in need of efficient engineering process management that would be able to provide in-building coverage solutions in order to satisfy the customer’s expectation. This can be achieved by providing an end-to-end customer management guideline which involves a method of task escalation that will be able to handle customer complaints by providing solutions to enhance the coverage at a given location. The demand for better cellular coverage and higher data rates entails the RF design planners to find possible ways to bring the signal source closer to the mobile user. Therefore, the proposed method is to implement a Distributed Antenna System (DAS) in order to enhance the reception in a building. A DAS incorporates the usage of external antennas, in-building antennas, cables, connectors, splitters, directional couplers, and coverage enhancers such as repeaters. A site survey is done initially at the affected areas to obtain pre-coverage measurements performed at the affected area. Then, a proper design plan which will include installation floor plans and link budget calculations will be done to ensure the design proposed is attainable. A performance test will then be performed to ensure that the solution provided is able to strengthen the coverage signal for the customers inside the building.