Letter Card Driver Safety Structure Of Workflow Model And Simulation Technology Research

With the support of the National863Program,"process management oriented software production line ", the research areas of the dissertation include workflow process model, capability analysis and correctness verification of workflow model.WFMC has put forward a series of reference specifications in order to form a common standard which all workflow systems should act upon, but in fact these specifications does not become real standards of market. For the present there are a huge amount of workflow models and process definition languages. The dissertation aims at Xinpai-driven workflow model introduced by software engineering institute of north-west university.Since concept of workflow patterns has been introduced by Aalst V.M.P., it has been broadly used to analyze and evaluate expressive capacity and applicability of various workflow models and process languages. The dissertation analyzes the degree of support of Xinpai-driven workflow model with43control flow patterns in detail, on the one hand we affirm the expressive capacity of Xinpai-driven workflow model to business requirements, on the other hand it is found that there exist some problems in the model:(1) the model can not express some important patterns due to absence of some specific model elements;(2) the degree of support with control flow patterns is not high enough, it mainly reflects in that the model can not completely satisfy the contexts of control flow patterns, for example the safety in execution of some patterns. Therefore, the dissertation carrys out some necessary modifications and extensions aiming at static structures and dynamic execution rules of original Xinpai-driven workflow model in order to raise expressive capacity and degree of support with control flow patterns of the model.The dissertation researches static structures of the model using formal methods. Main achievements include:(1)concluding five basic control structures which are respectively sequence structure, split-join structure, split structure, join structure and loop structure;(2)introducing corresponding identification algorithms for five basic stuctures;(3)finding various types of relationships of basic stuctures and formation reasons. In the research there are some key definitions and algorithms, such as the definitions and search algorithms of main path and loop path, the definitions and identification algorithms of focal point and aggregation point, the definitions and identification algorithms of non-loop transition and loop transition, the definitions and identification algorithms of in-structure transition and out-structure transition etc.Similarly the dissertation researches dynamic execution rules of the model using formal methods. We study the concession and the result of occurrence of various types of activities respectively in synchronizedarea and asynchronizedarea. At the same time we study preliminarily the phenomenon of multiple concurrent control flows(MCCF), including formation reasons, positions of occurrence and characteristics of MCCF structure. In the model research the differentiation of transitions in three perspectives plays a big role to define various static structures accurately and clarify the dynamic execution rules, including the differentiation based on path (non-loop/loop transition), the differentiation based on structure (in-structure/out-structure transition), the differentiation based on execution rule (common/goback transition).Base on the research achievements above-mentioned, the dissertation carrys out some suitable modifications and extensions to the original model and put forwards "safe Xinpai-driven workflow model", the main characteristics include:1) Keeping backward compatibility with the original model.2) Extension to meta model:adding new "SAFE-BLOCKED" conformance class; adding structured partial join, cancelling partial join and trigger activity type; extending some attributes of Xinpai box such as capacity, status and resource lock; extending some attributes of transition including weight and type. The extension to meta model raises expressive capacity of the model further and forms the fundation to raise safety of process execution.3) Solving the problem of identification to various pattern areas based on achievements of static model structures.4) Raising safety and reliability of the model by two aspects, respectively defining the safe structure and corresponding criterion rules, putting forward the "strategy of safe execution".Compared with the original Xinpai-driven workflow model, the "safe Xinpai-driven workflow model" possesses better expressive capacity and higher degree of support with43control flow patterns.Finally, the dissertation researches verification and simulation technologies aiming at "safe Xinpai-driven workflow model". The version1.0of process verification and simulation tools has gained software copyright. It has realized:(1)basic syntax check at meta model level;(2)verification to process definition based on safe structure theories;(3)process simulation based on "the algorithm for arranging events based on path coverage rule" in order to find process defects and optimize process by the greatest degree.