Rekayasa Perangkat Lunak
(Software Engineering)
Andi Sunyoto, M.Kom
FAQs about software engineering
What is software?
What is software engineering?
What is the difference between software
engineering and computer science?
What is the difference between software
engineering and system engineering?
What is a software process?
FAQs about software engineering
What are the costs of software engineering?
What are software engineering methods?
What is CASE (Computer-Aided Software
Engineering)
What are the attributes of good software?
What are the key challenges facing software
engineering?
What is software?
Computer programs and associated documentation
such as requirements, design models and user manuals.
Software products may be developed for a particular
customer or may be developed for a general market.
Software products may be
Generic - developed to be sold to a range of different customers e.g. PC software such as Excel or Word.
Bespoke (custom) - developed for a single customer according to their specification.
New software can be created by developing new
What is software engineering?
Software engineering is an engineering
discipline that is concerned with all aspects of
software production.
Software engineers should adopt a systematic
and organised approach to their work and use
appropriate tools and techniques depending on
the problem to be solved, the development
What is the difference between software
engineering and system engineering?
System engineering is concerned with all
aspects of computer-based systems
development including hardware, software and
process engineering. Software engineering is
part of this process concerned with developing
the software infrastructure, control, applications
and databases in the system.
System engineers are involved in system
specification, architectural design, integration
and deployment.
What is a software process?
A set of activities whose goal is the
development or evolution of software.
Generic activities in all software processes are:
Specification - what the system should do and its development constraints
Development - production of the software system Validation - checking that the software is what the
customer wants
Evolution - changing the software in response to changing demands.
What is a software process model?
A simplified representation of a software
process, presented from a specific perspective.
Examples of process perspectives are
Workflow perspective - sequence of activities; Data-flow perspective - information flow;
Role/action perspective - who does what.
Generic process models
Waterfall;
Iterative development;
What are the costs of software
engineering?
Roughly 60% of costs are development costs,
40% are testing costs. For custom software,
evolution costs often exceed development
costs.
Costs vary depending on the type of system
being developed and the requirements of
system attributes such as performance and
system reliability.
Distribution of costs depends on the
development model that is used.
Activity cost distribution
Wat erfall m odelIt erative developm ent
Com ponent-based software eng ineering
Developm ent and evolution costs for long-lifetim e sy st em s
10 200 30 400
0
Specification Design Developm ent Integ ration and testing
25 5 0 75 100
0
Specification Developm ent Integ ration and testing
2 5 5 0 75 1 00
0
Specification Iterative developm ent Sy stem testing
2 5 5 0 75 1 00
Product development costs
Specification Development Sy stem testing
2 5 50 7 5 100
What is CASE (Computer-Aided Software
Engineering)
Software systems that are intended to provide
automated support for software process
activities.
CASE systems are often used for method
support.
Upper-CASE
• Tools to support the early process activities of requirements and design;
Lower-CASE
• Tools to support later activities such as programming, debugging and testing.
What are the attributes of good software?
The software should deliver the required functionality
and performance to the user and should be maintainable, dependable and acceptable.
Maintainability
Software must evolve to meet changing needs;
Dependability
Software must be trustworthy;
Efficiency
Software should not make wasteful use of system resources;
Acceptability
Software must accepted by the users for which it was
designed. This means it must be understandable, usable and compatible with other systems.
What are the key challenges facing software
engineering?
Heterogeneity, delivery and trust.
Heterogeneity
Developing techniques for building software that can cope with heterogeneous platforms and execution environments;
Delivery
Developing techniques that lead to faster delivery of software;
Trust
Software category:
system software:
computer software designed to operate the computer hardware and to provide and maintain a platform for running application software. The computer BIOS and device firmware.
The operating system (prominent examples being Microsoft Windows, Mac OS X and Linux)
Utility software, which helps to analyze, configure, optimize and maintain the computer.
application software:
is a computer software designed to help the user to perform singular or multiple related specific tasks. Examples include enterprise software, accounting software, office suites, graphics software, and media players.
Software category:
engineering/scientific software:
is a computationalsoftware program used in scientific, engineering, and mathematical fields and other areas of technical computing.
embedded software: is computer software
which plays an integral role in the electronics it
is supplied with.
Embedded software is 'built in' to the electronics in cars, telephones, audio equipment, robots, appliances, toys, security systems,
pacemakers, televisions and digital watches, for example. This
software can become very sophisticated in applications like airplanes, missiles, process control systems, and so on.
Software category:
product-line software: tools and techniques for
creating a collection of similar software
systems from a shared set of software assets
using a common means of production.
For example, automotive manufacturers can create unique variations of one car model using a single pool of carefully designed parts and a factory specifically designed to configure and assemble those parts.
WebApps (Web applications):
is an application that is accessed over a network such as the Internet or an intranet. The term may also mean a computer software application that is hosted in a browser-controlled environment (e.g. a Java
applet)[citation needed] or coded in a browser-supported language (such as JavaScript, combined with a browser-rendered markup
Software category:
AI software:
is the intelligence of machines and the branch of computer science that aims to create it. Sistem seperti ini umumnya dianggap komputer. Kecerdasan
diciptakan dan dimasukkan ke dalam suatu mesin (komputer) agar dapat melakukan pekerjaan seperti yang dapat dilakukan manusia. Beberapa macam bidang yang menggunakan kecerdasan buatan antara lain sistem pakar, permainan komputer (games), logika fuzzy, jaringan syaraf tiruan dan robotika.
Software Evolution
First Era:
Batch orientasi Distribusi terbatas
Perangkat lunak Customasi
Second Era:
Multiuser Real-time Database
Third Era:
Sistem terdistribusi Embedded intelligent Low hardware cost
Fourth Era:
High Performance Desktop System OOP Technology
Expert Sistem Neural Network
Problem without SE ?
Tidak sesuai kebutuhan
Over Budget
Terlambat
Error
Mitos Manajemen
Mitos:
Saya sudah mempunyai perangkat H/w dan S/w terbaru.
Kenyataan:
Tidak sekedar H/w tinggi. Ternyata untuk mencapai produktivitas tinggi diperlukan CASE
Mitos Manajemen
Mitos:
Jika menambah jumlah programmer dapat mengejar ketinggalan.
Kenyataan:
Menambah jumlah programmer ketika proses
berjalan akan semakin ketinggalan, karena dapat memperlambat pekerjaan.
Mitos Pelanggan
Mitos:
Pernyataan umum obyektif sudah dapat untuk menuliskan program. Detail belakangan.
Kenyataan:
Definisi awal yg buruk merupakan awal kegagalan membangun S/w. Deskripsi detail informasi, fungsi, unjuk kerja, interface, desain contraint, validasi
Mitos Pelanggan
Mitos
Kebutuhan proyek yang terus berubah dapat diakomodasi, karena S/w bersifat fleksibel.
Kenyataan:
Perubahan dapat menyebabkan “pergolakan” dan
membutuhkan sumber daya yang besar.
Perubahan software biayanya jauh lebih besar dibanding perubahan di awal.
Mitos Praktisi
Mitos:
Teknik Perancangan dan Analisa hanya memperlama selesainya program.
Kenyataan:
Program yang dirancang dengan teliti, detail, seksama, selesai lebih cepat dengan tingkat efektifitas lebih tinggi.
Mitos Praktisi
Mitos:
Kualitas program hanya dinilai ketika sudah dapat berjalan.
Kenyataan:
Tinjauan perangkat sebelumnya merupakan cara efektif untuk memfilter kualitas perangkat lunak.
Mitos Praktisi
Mitos:
Ketika program selesai dan jalan, maka proyek dianggap sukses.
Kenyataan:
Program berjalan adalah bagian dari konfigurasi perangkat lunak yang menyangkut program,
dokumen dan data.
Dokumentasi merupakan fondasi untuk
pengembangan yang berhasil, dan memberikan tuntunan untuk pemeliharaan.
