Requirement Engineering Based On Combining Goal With Scenarios

Software requirements refer to the users'expectation on function, behavior, ability, design restriction of software system. Understanding and analyzing the issue and its environment, setting up models for concerning information, function and system behavior, elaborating and completing users'requirements, finally forming requirement specification are requirement analyzing stages of software life circle.Requirement engineering is a subject that the applications of proved effective technology method, making sure users'requirements, helping analyzers understand issues and defining all outside features of target system. Requirement engineering describes to-be-developed system and its behavior features and concerning restriction by suitable tools and signs, forms requirement specification and supports users'variable requirement succession. Software requirement engineering is a subject that analyzes and records software requirement into some main subsystems and tasks and assigns them to software, then translates these system requirement into software description and function parameters by a series of repeated analysis, design, comparative research and prototype development process.With development of software system, requirement becomes more and more important in software design. Acquiring correct and complete requirement specification is the point of various requirement engineering methods. Nowadays, there are two rising important requirement in modern software engineering: goal-oriented requirement engineering method and scenario-oriented requirement engineering method. Both of them have advantages and disadvantages. Description of goal is based on linear temporal logical in goal-oriented requirement engineering methods which apply formal methods to guarantee requirement correctness and completement accurately. However, the big problem in goal-oriented requirement method is difficult to acquire initial goal of system correctly. Scenario-oriented requirement engineering method uses event trace diagram to describe specification. Description of event trace makes analyzers understand system from fragment behavior easily, which helps to acquire initial goal. But event trace diagram describing fragment information can not guarantee the completement and correctness well. This thesis integrates these two methods based on summarizing both advantages and disadvantages of goal-oriented method and scenario-oriented method to form requirement engineering based on combining goal with scenario method. This method improves the shortcomings of simple scenario-oriented method and goal-oriented method and makes the most of their advantages so as to guarantee correctness and completement of requirement, provide visual checking method of requirement specification as well.The main content of this thesis is: the transition of event trace diagram to opera- tional goal; the judgment of event trace diagram equaling to operational goals set; the research on goal elaborating method; the judgment of system goal's completement; the simplication of goal divergence probing; the divergence of agents hierarchy; the rules set of operation goals; the research of HRAFSM; the visualization of requirement specification; the integration of goal obstacle method and conflict probe method to the requirement based on goal integrating scenario, which guarantee completement and correctness of goals and scenarios.The contributions of this thesis are:1. The arithmetic of transition of event trace diagram to operational goals and the equal definition and judge equal theorem of event trace diagram to operational goals set. This thesis provides arithmetic of the transition of event trace diagram to operational goals. The transition can work automatically in computer. Meanwhile, this thesis provides a judge theory of event trace diagram equivalence to operational goals set, guaranteeing the arithmetic's correctness of transition in semantics.2. Predication-driven goals elaborate arithmetic. This thesis sets up predication- driven goals elaborate arithmetic to make the down-to-up goal elaborate process automation possible. The arithmetic can be used in computer after less improvement. This thesis also provides a judge method of system goal's completement according to predication classification of monitoring predication set in system goals.3. Theorem of decreasing divergence probing. This thesis puts checking and operating mechanism of goal conflict into requirement engineering method based on goal integrating scenario and guarantees the correctness of requirement. At the same time, in order to decrease complexity goal divergence probing, this thesis provides two theorems to diminish the input data quantity of divergence checking arithmetic to simplify goal divergence probing process.4. Simulation of operation goal set. This thesis builds up rules set for operational goal, agent and software system and provides theoretic basis for divergence of agent levels so as to combine the system that descripted by goals and HRAFSM, which is the precondition of specification simulation. This thesis realizes simulation requirement checking method by rules interpreter this method not only judges the correct of system but also benefit to system analysis and testing.Finally, this thesis takes the example of safe computer and discusses the transition process of event trace diagram, goal elaboration based on predication, goal obstacle analysis and goal correctness analysis in turn. It gets complete and correct system goal rules, so it shows the validity and feasibility of method provided by this thesis.