Each large program that develops systems and software is currently required to assemble a wide array of software products to provide piecemeal capabilities necessary for completing different stages of the engineering lifecycle. Once installed, the daunting task of configuring and gluing them together begins. After years of effort, the program may have a toolset that is adequate for its current needs, but is ill-suited for growth and is far from optimized. In addition, the resulting tools are disconnected, sporadically maintained, and use an overwhelming array of disjointed user interfaces to access partially redundant data. Additionally, such a toolset often carries with it multi-million dollar software licensing, customization, configuration, and maintenance costs. Despite the tremendous effort involved in piecing together an engineering environment, it is not enough. Lean engineering demands a truly integrated engineering environment. There is an increasing acceptance and adoption of lean principles in product development and engineering. Lean principles focus on reducing waste. A major waste when developing complex systems is handing off work between separate functional disciplines and the associated knowledge loss. Someone who knows this first hand is Jonathan Ive, head of design at Apple, who stated that "The historical way of developing products just doesn't work when you're as ambitious as we are. When the challenges are that complex, you have to develop a product in a more collaborative, integrated way." Engineering a product in a more collaborative and integrated way requires an engineering environment that is itself tightly integrated. OSEE was designed and architected to provide Subject Matter Experts effective access to the data they need across the engineering lifecycle in a single, integrated environment. OSEE is being developed using a spiral methodology and deployed as those capabilities are needed to develop the next generation mission software for an existing Boeing aircraft. Key deployment milestones of OSEE achieved on this program are listed below.