Simplificação dos Modelos i* Trabalho de Fernanda Alencar Clarissa César Borba.

Apresentação em tema: "Simplificação dos Modelos i* Trabalho de Fernanda Alencar Clarissa César Borba."— Transcrição da apresentação:

1 Simplificação dos Modelos i* Trabalho de Fernanda Alencar Clarissa César Borba

2 Agenda Problema Apresentado Objetivo Conceitos: i* e Aspectos Solução do Problema Trabalhos Futuros Referências

3 Problema Apresentado Complexidade dos modelos i* para modelagem organizacional

4 Objetivo Processo para simplificar os modelos i* utilizando os conceitos fundamentais da orientação a aspectos Melhorar graficamente a legibilidade dos modelos i*

5 Abordagem i* Visão gráfica dos atores de um sistema de software, bem como as suas relações de dependências Oferece dois modelos: Modelo de dependência estratégica (Strategic Dependency - SD) Modelo de razões estratégicas (Strategic Rationale - SR)

6 Exemplo de um modelo SR

7 Aspect-Oriented Software Development - AOSD Técnicas e mecanismos para modularizar crosscutting concerns em módulos separados chamados aspectos Crosscutting concerns – interesses/preocupações transversais que não podem ser encapsulados usando os artefatos oferecidos pelas abordagens tradicionais. Ex: requisitos não funcionais

8 Solução do problema O que foi feito? Investigação de como os modelos i* podem ser usados para identificar crosscutting concerns durante a modelagem de early requirements Como foi feito? Definição de um conjunto de guidelines para identificar, representar e modularizar crosscutting concerns nos modelos i*

9 Simplificando os modelos i*

10 Identification of crosscutting concerns Guideline 1 (Repeated dependum): if a dependum is provided by at least two dependee actors, and the operationalization corresponding to that dependum is handled in the same way in all dependee actors, then this operationalization is a crosscutting concern. D1, D2 and D4 dependum have multiple occurrences in the model Task T1 Task T4 Task T2 Dependum D1 Dependum D2 Dependum D4 Dependum D4 Dependum D1 Dependum D2 It is also necessary to check if that their respective operationalizations are the same  Crosscutting concerns: T1, T2 and T4

11 Identification of crosscutting concerns Guideline 2 (Repeated tasks): if an internal task is related to an external dependency (directly or indirectly) and is required by (i.e. is a decomposition element of) two or more internal tasks (which are also related to other external dependencies), then that task is a crosscutting concern. T3 and T7 tasks are reused T3 is directly related to external dependency T6 and T7 tasks are indirectly related to an external dependency.  Crosscutting concerns: T3 and T7 Task T3 Task T7

12 Identification of crosscutting concerns The final list is: T1, T2, T3, T4 and T7 Task T 1 Task T 7 Task T 3 Task T 4 Task T 2 Guideline 3 (Redundancy): the lists of crosscutting concerns identified by Guideline 2 and Guideline 1, need to be merged together. To avoid redundancy, multiple occurrences are deleted

13 Crosscutting concerns representation Crosscutting concerns are special types of tasks which operationalize any dependum type (goal, softgoal, resource or task). Following the principles of AOSD we should –extract and modularize these tasks, –remove them from the original actors, and –place them in a new type of model element, The so called aspect.

14 The final representation

15 Simplificando os modelos i*

16 Identification of relationship among crosscutting concerns Dependee Actor Crosscutting Concerns T1T1 T2T2 T3T3 T4T4 T7T7 A(C/D 2 ) B(A/D 1 ) (D/D 2 ), (-/D 5 ) (C/D 3 )(C/ D 4 )(-/-) C(D/D 1 ) D (A/D 4 ) Table 1. Crosscuting concerns and its dependums Only T7 is not related to any dependum; it is a internal task in B dependee actor.

17 Identification of relationship among crosscutting concerns

18 There are three possibilities: Depende e Actor Crosscutting Concerns T1T1 T2T2 T3T3 T4T4 T7T7 A(C/D 2 ) B(A/D 1 ) (D/D 2 ), (-/D 5 ) (C/D 3 ) (C/ D 4 ) (-/-) C(D/D 1 ) D (A/D 4 ) (iii)the pair (-/dependum) which means that the crosscutting concern depends on some other actor through the dependum (i.e., the dependum is an output element of the crosscutting concern), for example, the pair (-/D5) related to task T2. (A/D 1 ) (ii)the pair (-/-) if the crosscutting concern does not have any dependency link (output dependum) or does not operationalize any dependums (input dependums). (-/-) (D/D 2 ), (-/D 5 ) Table 1. Crosscuting concerns and its dependums (i)the pair (depender_actor/dependum), e.g. (A/D 1 ) related with the T1 crosscutting concern;

19 Identification of Internal Elements Task-Decomposition Parent (TDP) Task-Decomposition Sub-elements (TDS) Means-End (ME) Contribution (C) Table 2. Internal elements related to crosscutting concerns in i* model. Dependee Actor Crosscutting Concerns T1T1 T2T2 T3T3 T4T4 T7T7 BTDS(T 3 ) TDP(T 3 ) ME(G 1 ), C(SG 1 ) TDP(T 1, T 4 ), TDS(Tree 3, T 2, T 7 ) TDS(T3, G 1, T 6, Tree 4) TDP(T 3 ), ME(G 1 ), TDP(T 6 )

20 Simplificando os modelos i*

21 The Composition rules The third step defines a set of rules and operators to help simplifying the i* models without loosing information from the original model. The composition rules define “where” and “how” a crosscutting concern affects other concerns in a system.

22 The Composition rules Table 3. Rules to external dependencies links in i* models R1R1 Aspect is related to scattered R2R2 Aspect has as depender | with the dependee R1 and R2 are proposed, respectively, to record (i) the depedum type that is scattered and involved with a dependency relationship (goal, task,softgoal or resource); Dependum D 1 Task T 1 (ii) the actors who depend upon the dependency relationship (depender actors). Actor A Actor B Aspect T1 is related to scattered D1 Aspect T1 has as depender A with the dependee B

23 The Composition rules R 3,R 4,R 5,R 6 and R 7 define rules to keep the task-decomposition with its related elements Task T 1 Actor B Table 4. Rule for a sub-task of a task decomposition link inside the expanded actor in i* model R3R3 Aspect is a sub- task of | Aspect. | | in depend ee R4R4 is decompo sed into | R5R5 depends on | provid ed by R6R6 is the root of | Aspect. | | in R7R7 is root in Aspect T1 is decomposed into Aspect T3 (R 4 )

24 The Composition rules Table 5.Rules for a means-end link in the SR model R8R8 Aspect. is the means of | Aspect. | | in R9R9 Aspect. contrib utes > to | in The means-end link is another kind of internal link in the i* model We are considering that the end element can be a goal or a softgoal, although it can be any type of dependum.

25 The Composition rules Task T 2 Actor B Rule 8 (R8) – Means-end link Task T 7 Goal G 1 Aspect T2 is the means of G1 in B Aspect T7 is the means of G1 in B. Rule 9 (R9) – Contribution link Aspect T2 contributes + to SG1 in B Softgoal SG 1

26 Trabalhos Futuros Especificar guidelines em termos de algoritmos Aplicar esta abordagem para mais estudos de caso Realizar mudanças no plug-in para representar corretamente o estereótipo de aspectos Realizar a análise trade-off

27 Referências Alencar, F., Silva, C., Moreira, A., Araújo, J., Castro, J.: Identifying Candidate Aspects with I-star Approach. In: Work. Of Early Aspects 2006 Alencar, F., Silva, C., Moreira, A., Araújo, J., Castro, J., Mylopoulos, J.: Towards na Approach to Integrate i* with Aspects. In: 8th Intl. Bi- Conference Work. On Agent-Oriented Information Systems (AOIS- 2006) Alencar, F., Silva, C., Moreira, A., Araújo, J., Castro, J., Mylopoulos, J.: Using Aspects to Simplify i* Models. Poster in the 14th International Requirements Engineering conference RE´06 Alencar, F., Silva, C., Moreira, A., Araújo, J., Castro, J., Ramos, R.: Proposta de Simplificação dos Modelos do i* com Aspectos. WASP06 Alencar, F., Moreira, A., Araújo, J., Castro, J., Ramos, R., Silva, C.: Dealing with the i* Models with Aspects. RCIS07 Alencar, F., Moreira, A., Araújo, J., Castro, J., Ramos, R., Monteiro, C., Mylopoulos, J.: Simplifying i* Models. AOIS07