Systems Engineering
System engineering can best be explained as coordinating multiple tasks within the two disciplines of engineering and engineering management. This paper highlights the systems method of coordinated tasks and its relevance concerning current and future business system life cycles: concept, design, planning, testing, optimization, and deployment. It defines the boundaries necessary for a robust life cycle and analysis to occur.
4. Requirements Types
4.6 Reliability
Reliability is the probability the system will perform its intended function for a specified time period. The inverse is probability of failure. It is related to Resilience, which is the ability to function in the face of internal damage or external failures. It is also related to Robustness, which is the ability to function in the face of external or internal variables, such as line voltage or temperature. A closely related measure is Availability, which is the probability a system can start operating at a random requested time, or the percentage of a total time interval it can be operated. A high reliability system may require multiple units in place, so that at least the minimum required number are available at a given time. An example is passenger airplanes, which require multiple engines for high reliability, in case one stops working.