Page 172 - DCAP405_SOFTWARE_ENGINEERING

Unit 9: System Engineering

9.6 Summary Notes

Systems Engineering integrates all the disciplines and specialty groups into a team effort
forming a structured development process that proceeds from concept to production to
operation.
Systems Engineering considers both the business and the technical needs of all customers
with the goal of providing a quality product that meets the user needs.
System models are hierarchical or layered as a system is represented at different levels of
abstraction. The top level of hierarchy presents the complete system.
The data objects, functions, behaviors are represented. As the hierarchy is refined or
layered, component level detail is modeled and finally system models evolve into
engineering models.
Good system engineering begins with a clear understanding of context – the world
view – and then progressively narrows focus until technical details are understood.

System engineering encompasses a collection of top-down and bottom-up methods to
navigate the hierarchy.

This unit introduced the main concepts of SYSTEM SIMULATION to model dynamic systems
by identifying variables and causal affects.
The model was parameterized with data and equations and simulated over time.

Simulation results can be viewed in a Data File editor, exported to other applications or
presented with configurable tables, charts and graphs.

9.7 Keywords

CM: Continuous Models
DEDS: Discrete event dynamic system

DM: Discrete Models
SUI: System Under Investigation
Vector Variable: A collection of variables organized as a linear array is called a vector variable.

9.8 Review Questions

1. Explain the meaning of the term:
(a) Isolated System (b) Closed System
(c) Morphological System (d) Cascading System
2. What are common characteristics of a system?
3. A new apartment building is being designed. It will have ten floors and will have six
apartments on each floor. There will, in addition be two underground parking levels. The
developer needs to make a decision about the elevator system that is to be installed in the
building. The choice has been reduced to two alternatives: either two elevators each with
a capacity of 15 or three smaller elevators

(a) Develop a list of possible performance criteria that could be used to evaluate the
relative merits of the two alternative designs.

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