Matakuliah
Tahun
Versi
: M0086/Analisis dan Perancangan Sistem Informasi
: 2005
:5
Pertemuan 21
Function
1
Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
• Mahasiswa dapat Menemukan Function (C3)
• Mahasiswa dapat Melengkapi Tipe dari Function
(C3)
• Mahasiswa dapat Membagi golongan dari
Function (C4)
2
Outline Materi
•
•
•
•
•
Update
Signal
Read
Compute
Function List
3
Aktivitas utama didalam
Application Domain Analysis
System Definition
and model
Interfaces
Usage
Next, we’ll look
at this activity
Functions
Requirements
(Mathiassen et al, 2000)
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
System
Definition
Evaluate
critically
Find
functions
Use Cases
Specify
complex
functions
Function list
6
Contoh Function List
Planning
Make schedule
Very complex
Update
Query possible
reservations
Make reservation
Complex
Read
Medium
Update
Cancellation
Simple
Update
7
System Architecture
user
Other system
Application
Domain
Problem
Domain
Interface
Function
Model
system
8
Tipe dari Functions
• Ada 4 tipe function
utama
• Tipe Function :
Kalsifikasi dari suatu
function berdasarkan
interaksi antara
component dan
context dari sistem
I
AD
F M
I
AD
F M
*
*
PD *
Update
I
AD
F M
PD
I
AD
F M
*
*
PD
Signal
Read
PD
Compute
Effect of processing
* Initiative
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
I
AD
F M
*
PD *
Update
• 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
I
AD
F M
*
PD
Read
• Activated by a need for
information by an actor
• As a result, computerised
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
I
AD
F M
*
PD
Compute
• Dimulai dari kebutuhan
aktor akan informasi
• Sistem kemudian akan
menghitung dan
menampilkan hasilnya
pada actor
• 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
AD
for the model?
• What is their significance?
*
What are the consequences
when they occur?
PD
Signal
• 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
I
F M
14
Example Function List
Planning
Make schedule
Very complex
Update
Query possible
reservations
Make reservation
Complex
Read
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
16
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
18
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
19
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
20
Terima kasih
21