Open Systems. The open systems approach is an integrated business and technical strategy to (1) choose commercially supported specifications and standards for selected system interfaces (external, internal, functional, and physical), products, practices, and tools, and (2) build systems based on modular hardware and software design. In order to achieve an integrated technical and business strategy, an integrated product team (IPT) process is needed that involves all interested parties, e.g. engineering, logistics, finance, contracting, industry, etc. Selection of commercial specifications and standards shall be based on those adopted by industry consensus based standards bodies or de facto standards (those successful in the market place); market research that evaluates the short and long term availability of products; a disciplined systems engineering process that examines tradeoffs of performance; supportability and upgrade potential within defined cost constraint; and allowance for continued access to technological innovation supported by many customers and a broad industrial base.