Fitting software architecture into the engineering process becomes a challenge when you are developing complex systems. What are the inputs? Where do they come from? How do I know that what the other disciplines are creating will meet my needs? How do I know I'm creating useful work products? Are they being produced at the right time? Recognizing this complexity, BAE Systems has developed the Integrated Engineering Methodology (IEM), a model-based, end-to-end methodology that seeks to ensure that only the products that are needed are developed and that development occurs at the right time. How do you do all that and maintain the organization at CMMI Level 5? This presentation describes the IEM, highlights the software architecture, and describes its relationship to the other elements of the methodology.