Systems Engineering (SE) proposes a series of methodologies and practices to ensure the successful development and operation of systems. Historically, many of the SE process applications were in the aerospace industry and the defense industry (INCOSE 2015). However, modern SE has a broader scope of applications (e.g., Product-SE, Enterprise-SE, Service-SE, etc). For a discussion of the impact of SE in ground-based observatories, see Swart and Meiring (2003).
Some of the reasons that led to the implementation of SE methodology in complex projects are: (i) Limited product effectiveness; (ii) Results often unrelated to the actual needs; (iii) Serious delays in schedules; (iv) Excessive costs; (v) Bad development directions; and (vi) Need for unification or standardization of practices created in different fields.
The early implementation of SE practices aims to guarantee a good understanding of the needs and requirements of the system from concept to disposal. SE design methodology will widely consider the system life cycle, the needs of the final users, and mitigate risks as early as possible by working closely with specialized engineers for design decisions.
Figure 1 illustrates the importance of the application of SE throughout cost allocation per phase and expenses in case of defect. This pattern has been observed in different projects from different domains and has been used to justify the intense use of SE practices at the concept and design phases of a project, since those phases are where decisions will allocate most of the cost of the project and errors will be corrected with less expense.