1 Pertemuan 21 Function Matakuliah: M0086/Analisis dan Perancangan Sistem Informasi Tahun: 2005 Versi: 5

2 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)

3 Outline Materi Update Signal Read Compute Function List

4 Next, we’ll look at this activity System Definition and model Usage Interfaces Functions Requirements (Mathiassen et al, 2000) 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 Specify complex functions Find functions Evaluate critically System Definition Function list Use Cases

7 Contoh Function List

8 System Architecture user Other system Interface Function Model system Application Domain Problem Domain

9 Tipe dari Functions * Effect of processing Initiative Update * IFM AD PD * Signal * IFM AD PD Compute * IFM AD PD Read * IFM AD PD 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? Update * IFM AD PD *

12 Read Functions 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? Read * IFM AD PD

13 Compute Functions 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? Compute * IFM AD PD

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? Signal * IFM AD PD

15 Example Function List

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

21 Terima kasih