1 Pertemuan 11 Function dari System Matakuliah: M0446/Analisa dan Perancangan Sistem Informasi Tahun: 2005 Versi: 0/0

2 Learning Outcomes Pada akhir pertemuan ini, diharapkan mahasiswa akan mampu : Memberikan contoh dari tipe function

3 Outline Materi Tipe Function –Update –Read –Signal –Compute

4 Aktivitas utama didalam Application Domain Analysis

5 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

6 Sub-activities didalam analisa Function

7 Contoh Function List Planning Make ScheduleVery ComplexUpdate Query Possible Reservation ComplexRead Make ReservationMediumUpdate CancellationSimpleUpdate

8 System Architecture

9 Tipe dari Functions Ada 4 tipe function utama Tipe Function : Kalsifikasi dari suatu function berdasarkan interaksi antara component dan context dari sistem

10 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

11 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?

12 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?

13 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?

14 Signal Functions Activated by a change of state in the model Results in either displaying the signal to the actors or automatically intervening in the problem domain What are the critical states for the model? What is their significance? What are the consequences when they occur? How should the function identify that a critical state has been reached? How should the signal be reported to the AD or PD? How reliable and strong?

15 Example Function List Planning Make ScheduleVery ComplexUpdate Query Possible Reservation ComplexRead Make ReservationMediumUpdate CancellationSimpleUpdate

16 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

17 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

18 Contoh Functional Partitioning

19 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

20 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