Research On Method Of Requirements Change Impact Analysis Based On First Order Logic

For the software system at the present day,their requirements change continuously and new requirements emerge frequently.Therefore,Change impact analysis is an important activity in software maintenance and evolution,both for properly implementing a set of requested changes,and also for reducing the costs associated with the change implementation.Current research on change impact analysis has two main problems.On one hand,current approaches mainly focuses on change impact analysis between requirements and codes,there is a lack of research about change impact analysis within requirements and between R&A.On the other hand,the traditional method is based on requirement documents which are often textual artifacts with implicit structure,Most of relations among requirements are not given explicitly.Due to the lack of semantics of requirements relations,relations between R&A and change types,change impact analysis may produce high number of false impacted requirements and architectural elements.Requirements engineers and architect engineers may have to analyze all requirements in requirements document and all elements in atchitecture model for a single requirement change.This may result in neglecting and actual impact of a change.To solve these problems,this thesis proposes a approach based on first order logic(FOL).First order logic can provide a formal semantics for requirements relations and relations between R&A,For a given proposed requirements change,the propagation of the changes to related requirements and the architectural elements that implement the system properties to which proposed requirements changes are introduced can be indentified automatically based on the method of this thesis.The major work is listed as follows.Firstly,the thesis designs a requirement metamodel which only contains traceability informations based on an existing common metamodel,then we use a kind of specification for the textual requirement based on the metamodel above to provide a classification of change types.We provide a formal semantics for the changes types based on FOL.The formalization of requirements relations and changes is used for propagating proposed changes and consistency checking of proposed changes in requirements model.Besides,the algorithms for generating the set of impacted requirements automicially are designed.Secondly,we provide a metamodel contains requirements,architecture and traceability between R&A.Then we divide the changes types into Refactoring and Domain Change.At last we use the semantics of relations between R&A and changes to identify the architectural elements that satisfies the changed requirments.We also provide the algorithms for identifying the impacted architectural elements.Finally,we use a safety-critical system as the case study to analyze the change impact with-in requirements and between R&A to demonstrate the feasibility and effectiveness of the method.