AEROSPACE REPORT NUMBER: TOR-2009(8546)-8604 (REV. A), REUSE OF HARDWARE AND SOFTWARE PRODUCTS (27 JAN 2010)

AEROSPACE REPORT NUMBER: TOR-2009(8546)-8604 (REV. A), REUSE OF HARDWARE AND SOFTWARE PRODUCTS (27 JAN 2010)., Heritage and legacy designs are supposed to cost less, work better, and be more reliable! But increasingly these assumptions have proven invalid. Use of heritage or legacy elements specifically designed for multiple applications (i.e. commodity products) and reuse of heritage or legacy elements in applications that were not anticipated at the time of the original design have produced unintended consequences ranging from program cost and schedule impact to mission affecting failure. Proposals tout the value of heritage and legacy, but program schedules and budgets expand to accommodate subtle differences in application, design, mission environment, and late arriving failure data (popups). Mission failures are often attributed to erroneous assumptions about the applicability of the requirements, configurations, performance, and reliability of heritage and legacy elements. There are benefits to heritage and legacy systems, but realizing those benefits requires rigorous evaluation of the proposed reuse product capability against the new applications requirements. The reuse benefits cannot be achieved by assuming �plug-and-play� or �drop-in solution�. Supply chain managers need to oversee the configuration management systems of suppliers. Systems engineers need to take great care in applying heritage or legacy designs. Test engineering needs to test the design and the assumptions. Program managers need to anticipate the impacts of system complexity and late pop-up data. Customers need to understand the challenges faced by system integrators. And users need to accommodate the subtle difference in using follow-on designs.