The INCOSE Systems Engineering Handbook, version 3 (SEHv3), represents a shift in paradigm toward global industry application consistent with the Systems Engineering Vision. The objective for this document is to provide an updated description of the key process activities performed by systems engineers. The intended audience is the new systems engineer, an engineer in another discipline who needs to perform systems engineering or an experienced systems engineer who needs a convenient reference. The primary purpose of this version 3.2.2 update is to make this document a standalone reference fully supporting the Certified Systems Engineering Professional (CSEP) examination. Eleven appendices have been added for that purpose. Appendix D explains the context for this update in more detail.
The descriptions in this handbook show what each systems engineering process activity entails, in the context of designing for affordability and performance. On some projects, a given activity may be performed very informally (e.g., on the back of an envelope, or in an engineer’s notebook); on other projects, very formally, with interim products under formal configuration control. This document is not intended to advocate any level of formality as necessary or appropriate in all situations. The appropriate degree of formality in the execution of any systems engineering process activity is determined by:
a. the need for communication of what is being done (across members of a project team, across organizations, or over time to support future activities), b. the level of uncertainty, c. the degree of complexity, and d. the consequences to human welfare. On smaller projects, where the span of required communications is small (few people and short project life cycle) and the cost of rework is low, systems engineering activities can be conducted very informally (and thus at low cost). On larger programs, where the cost of failure or rework is high, increased formality can significantly help in achieving program opportuni ies and in mitigating program risk.
In a project environment, work necessary to accomplish project objectives is considered “in scope;” all other work is considered “out of scope.” On every project, “thinking” is always “in scope.” Thoughtful tailoring and intelligent application of the systems engineering process described in this handbook is essential to achieve the proper balance between the risk of missing project technical and business objectives on the one hand, and process paralysis on the other. Chapter 10 provides tailoring guidelines to help achieve that balance.
