Rey Steve P. Balatico BSCS III
Chapter 6: Architectural Design 1. When
describing a system, explain why you may have to design the system
architecture before the requirements specication is complete. The system architecture is to be designed first before describing the system itself simply because the architectural design serves as basis for for
the the
desc descri ript ptio ion. n.
Sinc Since e
it
invo involv lves es
iden identi tify fyin ing g
majo major r
syst system em
components, subsystems, and their communications, it !ill be easier in the description to specify !hich one goes to !hich subsystems. "nd !hen subsystems are already made, it !ill be easier to determine !hat components
are
needed
by
hard!are
manufacturers.
"lso,
the
architectural design provides a model for system costing.
You 2. You
have been asked to prepare prepare and deliver a presentation presentation to a non-technical non-technical
manager to ustify the hiring of a system architect for a new proect. Write a list of bullet points setting out the key points in your presentation. !aturally, you have to explain
what
is
meant
by
system
architecture.
Registry
System
!hich
contains
Information
#$traction
System,
Information Storage System and Information #valuation System provides the registry function of the manipulate delete,
the
and
information
add.
all system. In
about
Therefore,
!e
the have
that, "dministrator can
employee. Control
%or
e$ample,
System.
The
store,
&ecision
ma'ing System used to decide !hether a certain employee !ould be hired or not. 3.
"xplain why design con#icts might arise when designing an architecture for
which both availability and security requirements are the most important nonfunctional requirements. %or a system that prioriti(es security, design !ould include layered structure !herein there
is a
high
level of security
in every
layer
until the innermost one. )e can say then say that there is limited access to the layers of the system as a preventive measure. *n the other
hand,
if
availability
is
to
be
prioriti(ed,
there
should
me
multiple and redundant components !hich shall serve as bac' up for the system
that
can
also
be
updated
!ithout
stopping
the
!hole
system.
Therefore, for a system !hich see's both availability and security at the same time, there !ill be design conflicts. 4.
$raw diagrams showing a conceptual view and a process view of the
architectures of the following systems% •
&n automated ticket-issuing system used by passengers at a railway station.
•
& computer-controlled video conferencing system that allows video, audio, and computer data to be visible to several participants at the same time.
•
& robot #oor cleaner that is intended to clean relatively clear spaces such as corridors. 'he cleaner must be able to sense walls and other obstructions.
5.
"xplain why you normally use several architectural patterns when designing the
architecture of a large system. &part from the information about patterns that ( have discussed in this chapter, what additional information might be useful when designing large systems) Sometimes,
large
systems
are
li'e
relationships.
They
can
get
complicated. This is !hy !e need to use several architectural patterns in the design of such large systems. )hen !e loo' into it, there may be parts of a system
that prioriti(es
some other
prioriti(e
components
+for instance security !hile
something else.
Then,
!e could see
!hat appropriate ma'e
use
of
addition, it
pattern
should
clientserver is
useful to
be
!hile 'no!
follo!ed. *ne another
ho! to
subcomponent
re-uires
communicate
could
repository. or connect
In
these
subcomponents very !ell even they different patterns. This is needed so that the !hole large system !ill ma$imi(e the benefits and minimi(e dra!bac's.
6.
*uggest an architecture for a system +such as i'unes that is used to sell and
distribute music on the (nternet. What architectural patterns are the basis for this architecture) Clientserver model is the appropriate architectural pattern for such 'ind of system. iTunes stores all the music they sell in a database !here the client can search these trac's by artist name, genre, etc. all via !eb based interface. "lso, trac's can be do!nloaded and paid accordingly. Then, the server manages the music ordering also via !eb based interface.
7.
"xplain how you would use the reference model of &*" environments +available
on the books web pages to compare the ($"s o/ered by di/erent vendors of a programming language such as 0ava.
8.
1sing the generic model of a language processing system presented here, design
the architecture of a system that accepts natural language commands and translates these into database queries in a language such as *23.
9.
1sing the basic model of an information system, as presented in 4igure 5.65,
suggest the components that might be part of an information system that allows users to view information about #ights arriving and departing from a particular airport. At the top layer is the web browser the user uses to access the airport website. The second layer would be comprised of web forms that collect information of the flight the user wants to look up or search for general time ranges. The next layer is the server at which the flight time request is sent, will receive the flight information collected and process it into query. The last layer is the actual database server which will query the database for the specified flights or time range of flights, and if something goes wrong during the transaction any updates will be rolled back.
10. *hould
there be a separate profession of 7software architect whose role is to
work independently with a customer to design the software system architecture) & separate software company would then implement the system. What might be the di8culties of establishing such a profession)
