ABSTRACT
In the previous chapters, we have learned about the basic systems concepts, system life cycle, and major processes that are involved in systems engineering design. No matter what kind of system is being designed, from a small appliance to a complex system like a Boeing 787, they all share the same characteristics; that is, every design is driven by systems requirements. Requirements driven is perhaps the most significant characteristic for systems engineering. In the early years of man-made system history, the importance of the system requirements was often ignored; designers used to start their configuration process with little knowledge of what users really wanted, or started with partial understanding of the system needs, hoping to incorporate more needs during the design process. With many failures, costs, and delays involved in the later changes of system needs, lessons were learned the hard way. We now have realized that without having a complete picture of what users need and formally translating that into systems requirements, it is nearly impossible to design a complex system within its time and budget limits. The requirements are vital to the success of the system design. Although systems requirements were briefly introduced in Chapter 2, we feel that it is necessary to revisit the concept of system requirements here in greater detail for readers to grasp the idea of performing requirements analysis (RA). This chapter is perhaps one of the most important chapters in the whole book, as it lays out the foundations of systems design, so that the system is built effectively and efficiently. System requirements analysis (SA) is perhaps the determining point for systems success; as the old proverbs tell us, “the pen follows where the mind reaches,” or “when conceiving ideas first, writing is easier.” In Chinese culture, it was said that “grinding the ax first will facilitate cutting the firewood.” These proverbs all imply the same meaning; that is, spending effort in early planning should not be neglected, just like RA in system planning.
