2.4 SIMILAR
A simple framework acronym for general systems engineering is described in a SIMILAR acronym. This framework provides one of the better guides for assessing project management methods.
It is critical to understand that these processes are NOT temporal, they are parallel and highly iterative.
graphic
State the problem
The problem statement starts with a description of the top- level functions that the system must perform. The can be in the form a vision, mission statement, and mission requirements, a set scenarios for how the system will be used and how it will interact with other systems or a description of the deficiency that must be ameliorated.
Most mandatory and preference requirements should be traceable to this problem statement.
Acceptable systems must satisfy all mandatory requirements
Investigate the alternatives
Alternative solutions are created and are evaluated based on performance, schedule, and cost figures or merit. No single solution is likely to be the best across all figures of merit. Multi- criteria decision- aiding techniques are available to discover the preferred alternatives.
This analysis is repeated as better data becomes available.
Model the system
Models will be developed for most alternate designs of the product system. The model of the preferred alternative will be expanded and used to help manage the system throughout its entire lifecycle.
Integrate
Systems, business processes, and people must be integrated so that they integrate with one another. Integration means bringing things together so they work as a whole. Interfaces between subsystems must be designed to facilitate the movement of physical items, information and energy. Subsystems should be defined along natural boundaries.
Subsystems should be designed to minimize the amount of information, physical items and energy exchanged between subsystems through their interfaces
Launch the system
Launching the system means using the system to obtained results. This is where the team learns if the system does what it is intended to do.
Access performance
Figures of merit, technical performance measures and metrics are all used to measure performance. Figures of merit are used to quantify requirements in he tradeoff studies. They focus on the product.
Re-evaluate all the phases
Re-evaluate is the most important of all the system engineering processes. Re-evaluation is a continuous process.
Re-evaluation means observing outputs and using this information to modify the system, the inputs, the product, or the process.