Transformation and Verification of System Scenarios

[[abstract]]對系統軟體而言，需求工程(Requirement Engineering)著力於探討如何實現系統需求之設計目標、功能、和限制等，而以劇本為基礎之系統需求規格被認為可以有效率且有意義的描述需求工程。在描述劇本為基礎之系統需求規格的系統劇本時，常以各種UML圖描述多系統劇本，但多系統劇本在敘述上有著諸如不一致或不可行等問題，而在問題的驗證上卻有著因為UML的敘述不易驗證出錯誤的情況。 故本研究提出一個系統劇本轉換方法，轉換系統劇本成為易驗證之系統需求模型後，對此模型進行需求模型分析，並針對多系統劇本之一致性及可行性做驗證。此方法以UML和派區網(Petri Nets)的轉換為中心，建立對應規則轉換成派區網，建立與系統劇本吻合之行為模型；接著，將以派區網所描述之模型做合成，並利用派區網驗證，找出編輯系統劇本時不一致或不可行等的錯誤。驗證後，透過迴向轉換指出系統劇本的錯誤位置與可能原因，可以用來讓使用者更快修正系統劇本錯誤。 研究成果顯示，本研究提出之方法可解決以UML編輯之系統劇本問題的驗證，除透過多系統劇本的串列合併與平行合併之合成方法，可合理推論出劇本間衝突或矛盾外，藉由正向與迴向的唯一對應性轉換，可明確定位出系統劇本問題之所在。[[abstract]]For the requirement development of system software it is focused on how to realize its design goals functions and constraints To describe the requirement the scenario–based specification in UML is effective and meaningful Because of insufficient characteristics of UML these scenarios exist inconsistency and non–feasibility issues which are not easy to process and verify In this paper we propose a scenario transformation methodology based on mapping rules to forward transform the UML scenario–based specification into Petri Nets for constructing the system behavior model To synthesize different models the sequential and parallel conjunctions are provided to verify these models by Petri Nets tools After verification with errors the backward transformation points out what and where these errors are and what the reasons of these errors are The results show that the conjunctions can effectively synthesize Petri Nets models for feasibility and consistency issues without losing relations between the scenario