This paper presents a software engineering process that includes family-based aspects for aero-engine control software. The process uses a “family capability” derived from family analysis of the embedding system. This analysis allows reuse capability to be designed into the process by exploiting prior knowledge of the differences between members of an engine family. The process described follows the traditional software lifecycle. However, the nature of the stages is modified to incorporate the use of the family capability, essentially to allow systematic application of both compositional and generational reuse throughout the development process. The process described was evaluated on a trial project to develop, and subsequently modify, a thrust reverser system for a small aero-engine. Initial results show that this process can reduce effort for both initial and subsequent developments through the use of the family capability.