Systems Engineering

4.4 Technical Risk

Especially in the early stages of design, the engineering process may reveal gaps in knowledge, performance uncertainties, resources which are not available, or other issues which prevent selection, optimization, or synthesis of a design. These issues can prevent progress to the next stage of the project, or cause a final design which does not meet desired goals. Measures of these unknowns are given the general name Technical Risks. For example, a new technology which has not been demonstrated yet, i.e. a fusion rocket, would be rated as high risk, while a chemical rocket, which has decades of operating history, would be comparatively low risk. A mass budget considerably below past experience or with insufficient margin during preliminary design would be high risk. New research, modeling, or prototyping can be done to reduce the risks, or the system modified to avoid them. Before these risk reduction efforts the risks will still exist, and it is necessary to account for them. Otherwise you accept the alternate risk of the system not performing as desired or even at all.

Not every risk will be known at the start of a project, but sound engineering practice is to identify them as early as possible, and to allow for modifying development plans when they appear. Depending on how much new technology is included in a project, sufficient performance, time, and cost margins should be included for unexpected problems caused by technical risks. Technical risk is gradually retired during the design and production of a system. Once a system is operating, a small uncertainty remains for things like operating life or failure rates. These are not eliminated until the end of program operations. Even after disposal of a system, some environmental risk may remain. A prime example is nuclear waste, which is a hazard long after the reactor that created it has been demolished.