System Modelling
The system engineering is also known as a modelling process. Whether the focus is on the world view or the detailed view the engineer build models that are [MOT92]:
- Describe the processes which serve the requirement of the view under consideration
- Present the behaviour of the procedure and the assumptions on which the behaviour is based
- explicitly describe both endogenous and exogenous input to the model
Represent all linkages including output which will enable the engineer to better understand the view. To build a system model the engineer should consider a number or restraining factors:
1. Suppose that reduce the number of possible variations and permutations therefore enabling a model to reproduce the problem in a reasonable manner. As an example consider a 3D rendering product used by the entertainment company to create realistic animation. 1 domain of the product enables the representation of three-dimensional human forms. To Input in this domain encompasses the capability to input movement from a live human actor from video or by the creation of graphical models. The system engineering makes definite assumptions about the variety of allowable human movement so in which the range of processing and inputs can be limited.
2. Simplifications which enable the model to be build in timely manner. To define consider an office products industries which services and sells a wide variety of copiers related and fax machines equipment. The system engineer is modelling the requirement of the service company and is working to understand the flow of information that spawns a service order. While a service order can be derived from much origin the engineer types only 2 sources that are: external request or internal demand. This enables a simplified partitioning of input which is needed to generate the work order.
3. Limitation which helps to bind the system example for an aircraft avionics system is being modelled for a next generation aircraft. Since the aircraft will be a 2-engine design all monitoring domains for propulsion will be modelled to contain a maximum of 2 associated redundant systems and engines.
4. The Constraints which will guide the manner in that the model is established and the approach taken when the model is implemented example for the technology infrastructure for the 3D rendering system define above is a single Power PC-based processor. The computational complexity of problems must be constrained to fit within the processing bounds imposed through the processor.
5. Preferences which indicate the preferred architecture for all functions, data, and technology. The preferred solution sometimes comes into conflict with other restraining factors. Still the customer satisfaction is often predicated on the degree to that the preferred approach is realized.
The resultant system model may call for a completed automated solution a manual approach or a semi-automated solution. In reality it is often possible to characterize models of every kind which serve as alternative solutions to the problem at hand. In essence the system engineer easily modifies the relative influence of various system elements to derive models of each kind.