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Systems Engineering and Multidisciplinary Design Optimization Commons™
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Full-Text Articles in Systems Engineering and Multidisciplinary Design Optimization
Premature Allocation Of Program Requirements To Suppliers, Bohdan W. Oppenheim
Premature Allocation Of Program Requirements To Suppliers, Bohdan W. Oppenheim
Systems Engineering Faculty Works
The paper presents a discussion of the difficulties of formulating stable requirements early in complex engineering programs, and the severe consequences on program execution. The problems are caused by the need to seek political and funding support for the program. Formal classical Systems Engineering (SE) and Program Management (CSEPM) methodology is based on the assumption that the knowledge to anticipate all interfaces and create good requirements exists early in the program, and it is only a matter of working out the details to build extremely complex devices such as satellites, aircraft, refineries, nuclear power plants and high speed rail. The …
Improving Affordability: Separating Research From Development And From Design In Complex Programs, Bohdan W. Oppenheim
Improving Affordability: Separating Research From Development And From Design In Complex Programs, Bohdan W. Oppenheim
Systems Engineering Faculty Works
This paper presents arguments for why defense programs creating physical systems should clearly separate three developmental phases from each other: research, development and design. Research is to be performed first by small teams of scientists addressing the "unknown unknowns" and maturing fundamental science from TRL of 1 to about 3. Next, development of physical modules is to be performed by small and highly specialized engineers. Finally, the system-level design should focus on efficient trading off the module locations, sizes and shapes versus system performance, mass, power requirements, etc. The design with all modules mature and available is equivalent to a …
Continuous Digital Simulation Of The Second-Order Slowly Varying Wave Drift Force, Bohdan W. Oppenheim, P. A. Wilson
Continuous Digital Simulation Of The Second-Order Slowly Varying Wave Drift Force, Bohdan W. Oppenheim, P. A. Wilson
Systems Engineering Faculty Works
A discussion is given on practical aspects of digital representation in time of the slowly oscillatory second-order wave drift force from a known force spectrum. The emphasis is placed on the computational efficiency and on the suitability of the simulation to a numerical integration of an equation of motion using a variable integration step size, where the force acts as the excitation of motion. The effect of approximating the original spectrum by a white spectrum is discussed. A sensitivity analysis is made to the range of frequencies of the spectra. The force time record is obtained by first generating at …