REKAYASA PERANGKAT LUNAK

Sistem Komputer 1. Hardware (Perangkat Keras), merupakan rangkaian elektronika 2. Software (Perangkat Lunak), merupakan program yang dijalankan pada komputer 3. Brainware (SDM)

Perangkat Lunak Instruksi Atau program komputer yang ketika dieksekusi akan memberi fungsi dan hasil yang diinginkan. Struktur data Yang memungkinkan program memanipulasi informasi Dokumen Yang menggambarkan operasi dan penggunaan program.

Jenis produk perangkat lunak Generik – dibuat untuk dijual ke suatu kumpulan pengguna, misal: Ms Office, MYOB, Sistem billing warnet (War-X, PCMAN dll) Bespoke (custom) – dibuat untuk suatu pengguna tunggal sesuai dengan spesifikasinya, misal : SIAKAD Univ. Trunojoyo,

Rekayasa Perangkat Lunak (Software Engineering) Ilmu yang mempelajari pembuatan software yang baik dengan pendekatan tehnik (Engineering approach) Ada beberapa cara / fase 1. Fase Perencanaan 2. Fase Pengembangan 3. Fase Pemeliharaan

Sejarah Rekayasa perangkat lunak  telah berkembang sejak pertama kali diciptakan pada tahun 1940-an hingga kini. Fokus utama pengembangannya :  untuk mengembangkan praktek dan teknologi untuk meningkatkan produktivitas para praktisi pengembang perangkat lunak dan kualitas aplikasi yang dapat digunakan oleh pemakai.

1945 - 1965: Awal Istilah software engineering digunakan pertama kali pada akhir 1950-an dan awal 1960-an. Saat itu, masih terdapat debat tajam mengenai aspek engineering dari pengembangan perangkat lunak. Pada tahun 1968 dan 1969, komite sains NATO mensponsori dua konferensi tentang rekayasa perangkat lunak, yang memberikan dampak kuat terhadap perkembangan rekayasa perangkat lunak.

1965 - 1985: krisis perangkat lunak Pada tahun 1960-an hingga 1980-an,  banyak masalah yang ditemukan para praktisi pengembangan perangkat lunak. Banyak projek yang gagal, hingga masa ini disebut sebagai krisis perangkat lunak. Kasus kegagalan pengembangan perangkat lunak terjadi mulai dari : projek yang melebihi anggaran, hingga kasus yang mengakibatkan kerusakan fisik dan kematian. Salah satu kasus yang terkenal antara lain meledaknya roket Ariane akibat kegagalan perangkat lunak.

1985 - sekarang Berbagai teknik, metode, alat, proses diciptakan dan diklaim sebagai senjata pamungkas untuk memecahkan kasus ini. Mulai dari : pemrograman terstruktur, pemrograman berorientasi object, perangkat pembantu pengembangan perangkat lunak (CASE tools), berbagai standar, UML metode formal diagung-agungkan sebagai senjata pamungkas untuk menghasilkan software yang benar, sesuai anggaran dan tepat waktu.

1985 – sekarang (Count.) Pada tahun 1987,  Fred Brooks menulis artikel No Silver Bullet, yang berproposisi bahwa tidak ada satu teknologi atau praktek yang sanggup mencapai 10 kali lipat perbaikan dalam produktivitas pengembangan perangkat lunak dalam tempo 10 tahun. Sebagian berpendapat,  no silver bullet berarti profesi rekayasa perangkat lunak dianggap telah gagal. Namun sebagian yang lain justru beranggapan, hal ini menandakan bahwa bidang profesi rekayasa perangkat lunak telah cukup matang, karena dalam bidang profesi lainnya pun, tidak ada teknik pamungkas yang dapat digunakan dalam berbagai kondisi.

Over Budget “A Home Office IT project run by Bull Information Systems is expected to blow its budget by millions of pounds and is hampered by a restrictive contract, according to a leaked report. The National Audit Office report, due in the Spring, is expected to reveal damning evidence that the project to implement two systems - the National Probation Service Information Systems Strategy, and the Case Record and Management System - for the probation service will cost £118m by the end of the year, 70 per cent over its original budget. “ Source: http://www.computing.co.uk/News/1116278

Over Budget / Over Schedule New air traffic system already obsolete: “National Air Traffic Services (Nats) is already looking at replacing the systems at its new control centre at Swanwick in Hampshire, even though the system doesn't become operational until next week. Now running six years late and £180m over budget, the system will control 200,000 square miles of airspace over England and Wales, looking after two million flights a year. It will finally go live on 27 January. “ “But long-term planners are already looking at replacing the systems.” “Swanwick was originally meant to be operational by 1997, but problems with the development of software by Lockheed Martin caused delays, according to Nats.” Source: www.vnunet.com/News/1128597 [24-01-2002]

Over Budget / Over Schedule (cont.) … Air traffic control system crashes again    http://www.vnunet.com/News/1130791  [10-04-2002]

Over Schedule Central Provident Fund (CPF) Singapore: a nationwide social security savings program for working Singapore citizens and Permanent Residents “IBM was unable to deliver according to contractual agreements despite extensions to the project deadline” The contract was eventually terminated in 2004 Central Provident Fund (CPF) Board filed a civil suit against IT giant IBM, over the deployment of a software system contracted to the vendor in 2001 Source: http://www.ncs.com.sg/media/

Usability AU$250 million ICS (Integrated Cargo System) to replace one that had been operating for more than 20 years Problems in the system have caused massive delays to container clearances, resulting in a backlog of cargo at some ports Electronic messages had been trapped for up to several hours, slowing clearance of imports and prompting claims from one state minister key NSW ports were within a couple of days of being forced to turn cargo- bearing ships away It is recommended that the sea cargo component of ICS be turned off, and industry revert to the previous system Source: http://www.zdnet.com.au/news/communications/

Safety Emergency calls system effectively did away with the radio and telephone calls to stations, with the computer dispatching crews to answer calls. But within hours, during the morning rush, calls were going missing in the system; ambulances were arriving late or doubling up on calls. Distraught emergency callers were also held in a queuing system which failed to put them through for up to 30 minutes. As many as 20 people died. Causes: assumed location of ambulances known, memory leak, operators left out Source: http://128.240.150.127/Risks/

Threats to Human Lifes Therac-25 medical accelerator: a radiation therapy device The device malfunctions and delivers lethal radiation doses at several medical facilities It could deliver two different kinds of radiation: either a low-power electron beam (beta particles) or X-rays Because of race condition, a quick-fingered typist could accidentally configure the Therac-25 so the electron beam would fire in high-power mode but with the metal X-ray target out of position At least five patients die; others are seriously injured Source: http://www.wired.com/news/technology/bugs/

Programming/Testing Error Ariane 5: took 10 years and $7 billion to produce At 39 seconds after launch, as the rocket reached an altitude of two and a half miles, a self-destruct mechanism finished off Ariane 5 Cause of error: computer program trying to stuff a 64-bit number into a 16-bit space, causing the rocket to make an abrupt course correction that was not needed, compensating for a wrong turn that had not taken place. The guidance system had in fact shut down 36.7 seconds after launch, when the guidance system's own computer tried to convert one piece of data -- the sideways velocity of the rocket -- from a 64-bit format to a 16-bit format = overflow error.

Programming/Testing Error (cont.) When the guidance system shut down, it passed control to an identical, redundant unit, which was there to provide backup in case of just such a failure. Guess what - the second unit (having the same software) failed too. In an earlier design decision, the programmers had decided that this particular velocity figure would never be large enough to cause trouble. After all, it never had been before. BUT Ariane 5 was a faster rocket than Ariane 4. One extra absurdity: the calculation containing the bug actually served no purpose once the rocket was in the air. Its only function was to align the system before launch. So it should have been turned off. Source: http://www.around.com/ariane.html

Human Error EDB Fellesdata AS runs the computer services of about half of Norway's banks. On Thursday 2 Aug 2001, they apparently installed about 280 disks in their Hitachi storage. Then, instead of initializing the new disks, they initialized all their disks -- thereby wiping out the entire warehouse. EDB Fellesdata considering lawsuits Source: http://www.digitoday.no/dtno.nsf/pub/

After 10 years... The Standish Group has studied over 40,000 projects in 10 years. Project failures have declined to 15 percent of all projects Projects meeting the “challenged” description—meaning that they are over time, over budget and/or lacking critical features and requirements— total 51 percent of all projects in the current survey. The average project cost overrun in 2004 was found to be 43 percent U.S. projects waste $55 billion from total project spending of $255 billion

Problem dalam Pengembangan Perangkat Lunak Tingginya harga Software Sangat bervariasi dalam penerapannya Yang diinginkan adalah untuk meningkatkan produktifitas.

Memberi jawaban yang diminta. Semula Program Sukses Bila : Bisa dieksekusi Memberi jawaban yang diminta. Sekarang : Bisa dieksekusi dengan cepat Memberi jawaban yang diminta Bisa dikembangkan

Produk Perangkat Lunak -------------(Aplikasi Software)------------------ System Software Real Time Software Business Software Enginering and Scientific Software Embeded Software Personal Computer Software Artificial Intelligent Software

System Software Sekumpulan program yang dibuat untuk melayani program lainnya. Misal: compiler, editor dan program manajemen utilities.

Real Time Software Program yang memonitor atau menganalisa atau mengontrol aktifitas sehari-hari. Elemen dari Real Time Software: Komponen pengumpulan data, yang mengumpulkan dan menformat informasi dari lingkungan eksternal. Komponen analisa, yang mentransformasikan informasi yang diperlukan atau aplikasi tersebut. Komponen kontrol/output, yang memberikan respon terhadap lingkungan eksternal. Komponen monitoring, yang mengkoordinasi komponen-komponen lainnya sehingga bisa memberikan respon yang Real Time (biasanya antara 1 milidetik/1 menit).

Business Software Software MIS (Management Information System) yang mengakses satu atau beberapa database yang berisi informasi bisnis. Contoh : payroll, account receivable/payable, inventory, dll.

Enginering and Scientific Software Batasan aplikasinya :  mulai dari astronomi sampai vulkanologi,  dari otomotif sampai pesawat ruang angkasa,  dari molekul biologi sampai automated manufacturing.

Embeded Software Biasanya diletakkan pada read only memory Digunakan untuk mengontrol produk dan sistem untuk pelanggan dan pasar industri. Misal: key pad untuk mengontrol microwave oven.

Personal Computer Software Misal: Wordprocessing, spreadsheet, computer graphic, multimedia, entertaintment, database management, personal and business financial application, akses database atau jaringan external, dan lain-lain.

Artificial Intelligent Software Software yang menggunakan algoritma non numerik untuk menyelesaikan permasalahan yang komplek. Areal AI (Artificial Inteligent) yang aktif dikenal dengan expert system atau knowledge based system. Cabang baru dari AI adalah Artifial Network. 

Klasifikasi Perangkat Lunak Sistem Operasi Program Utilitas Program Aplikasi Program Paket Bahasa Pemrograman

Tugas Individu Pilihlah sebuah aplikasi khusus (selain Sistem Informasi) dan tunjukkan (a) kategori dari aplikasi perangkat lunak (b) isi data (content) yang berhubungan dengan jenis aplikasi tersebut, sasaran serta features yang dimiliki aplikasi

Tugas Kelompok Download aplikasi LMS yang sudah ditetapkan untuk tiap kelompok dan install Buat laporan cara instalasinya, posting di web. Buat laporan Vision sesuai template SDLC_template_vision