Page 129 - DCAP308_OBJECT_ORIENTED_ANALYSIS_AND_DESIGN

Unit 10: System Conception

Notes
Did u know? The discovery of common abstractions and mechanisms greatly facilitates
the understanding of complex systems.
Most interesting systems do not embody a single hierarchy; instead, many different hierarchies
are usually present within the same complex system.

Example: As we first begin to analyze a complex software system, we find many parts
that must interact in a multitude of intricate ways, with little perceptible commonality among
either the parts or their interactions; this is an example of disorganized complexity.

As we work to bring organization to this complexity through the process of design, we must
think about many things at once. We are thus faced with a fundamental dilemma.

Notes The complexity of the software systems we are asked to develop is increasing, yet
there are basic limits on our ability to cope with this complexity.

When designing a complex software system, it is essential to decompose it into smaller and
smaller parts, each of which we may then refine independently. In this manner, we satisfy the
very real constraint that exists on the channel capacity of human cognition:
To understand any given level of a system, we need only comprehend a few parts (rather
than all parts) at once.

Self Assessment

Fill in the blanks:
8. A ............................ is a clear concise description of the issues that need to be addressed by
a problem solving team and should be presented to them before they try to solve the
problem.
9. ............................ languages provide a powerful tool for building flexible and extensible
software components.
10. ............................ looks at the problem domain, with the aim of producing a conceptual
model of the information that exists in the area being analyzed.
11. The development of a ............................ system is usually just a part of finding a solution to
a larger problem.
12. Implementation ............................ are dealt with during object-oriented design (OOD).

13. A system may be divided into multiple............................, representing different business,
technological, or other areas of interest, each of which are analyzed separately.
14. The external complexity usually springs from the “............................” that exists between
the users of a system and its developers.
15. When designing a ............................ software system, it is essential to decompose it into
smaller and smaller parts, each of which we may then refine independently.

LOVELY PROFESSIONAL UNIVERSITY 123