Matakuliah
Tahun
Versi
: M0446/Analisa dan Perancangan Sistem Informasi
: 2005
: 0/0
Pertemuan 11
Function dari System
1
Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
• Memberikan contoh dari tipe function
2
Outline Materi
• Tipe Function
– Update
– Read
– Signal
– Compute
3
Aktivitas utama didalam
Application Domain Analysis
4
Functions
“A facility for making a model useful for actors.”
• Express the intent of the system
• Express what is going to happen, but not how
• Need to find the right level of detail,
– Too general is too uncertain
– Too detailed is inefficient
– Inexperienced developers need more detail
5
Sub-activities didalam
analisa Function
6
Contoh Function List
Planning
Make Schedule
Very Complex
Update
Query Possible
Reservation
Complex
Read
Make Reservation
Medium
Update
Cancellation
Simple
Update
7
System Architecture
8
Tipe dari Functions
• Ada 4 tipe function
utama
• Tipe Function :
Kalsifikasi dari suatu
function berdasarkan
interaksi antara
component dan
context dari sistem
9
Mencari Functions
• Mencari functions dengan memeriksa classes,
events, and use cases
• Analisis secara sistematis dengan menggunakan
empat tipe function
• Hasil dari sub aktivitas adalah daftar kebutuhan
function dari system
• Termasuk didalamnya name, type, dan assessment
dari kompleksitas dari setiap function : simple,
medium, complex, or very complex
10
Update Functions
• Activated as a
consequence of an event
in the problem domain
• Results in a change in the
state of the model
• How is the event
observed and
registered? In which
use cases?
• How can the use cases
be supported by
updating functions?
• Which objects,
attributes, and
structures are affected
by the event? What
requirements for update
functions?
11
Read Functions
• Activated by a need for
information by an actor
• As a result, computerized
system displays parts of
the model to the actor
• What do the actors need
to know about the state of
the model (represents the
problem domain)?
• About which objects and
structures in the model do
the actors need
information?
• What ‘readings’ do these
give rise to?
12
Compute Functions
• Dimulai dari kebutuhan
aktor akan informasi
• Sistem kemudian akan
menghitung dan
menampilkan hasilnya
pada aktor
• Which computations, not
necessarily based on the
model, do the actors need to
have carried out?
• Does the computational basis
come from the actors, the
model, or both?
• Which computations form
complete wholes in the use
cases?
13
Signal Functions
• What are the critical states
for the model?
• What is their significance?
What are the consequences
when they occur?
• How should the function
• Activated by a change of
identify that a critical state
state in the model
has been reached?
• Results in either displaying
• How should the signal be
the signal to the actors or
reported to the AD or PD?
automatically intervening in
How reliable and strong?
the problem domain
14
Example Function List
Planning
Make Schedule
Very Complex
Update
Query Possible
Reservation
Complex
Read
Make Reservation
Medium
Update
Cancellation
Simple
Update
15
Menentukan Complex Functions
• Yang termasuk complex function
melibatkan beberapa tipe function
• Beberapa format :
– mathematical expression
– algorithm in structured language
– functional partitioning in the function list
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Contoh Algorithmic Specification
Query possible reservations:
given time or date or employee-name
search objects in time period-available and select those
who belong to employee-name, if known
have date, if known
cover point in time, if known
result objects of time period-available that fulfill the
criteria
17
Contoh Functional Partitioning
Planning
Make schedule
Create six-week period
Create standard distribution
for employee
Use standard distribution for
an employee
Adjust the distribution of
employees in a week
Very complex
Update
Simple
Medium
Simple
Medium
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Evaluate Systematically
• Work with the function list itself
– Functions must be mutually consistent
– Each function must be at an appropriate level of
abstraction
• Ensure total functionality is consistent with the
list
– prototype the usage - experiment
– review questions above for each type of function
– compare with system definition and models
• Ensure functions are not to general/vague or too
detailed
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Prinsip dari analisis Function
• Identify all functions.
– A complete list is very important
• Specify only complex functions.
• Check consistency with use cases and the
model.
– Checking this can reveal insufficient analysis
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