Rovement And Reduction Research Of EPMM Based On Time Constraints

With the popularization of computer application and the development of software engineering, a software system is becoming an important social assets, which helps the establishment reducing the cost, as well as enhancing the competitiveness. But with the requirement’s change, the software will becoming not applicable, which we called legacy system. This is the reason of software evolution.A software process which can support the software evolution (software evolution process)could afford a whole task frame of the software evolution. The EPMM(Evolution Process Meta-Model) mentioned in this thesis realized the modeling of software evolution process in different level by using the hierarchy method.No matter in what project, time is always important, as well as in software evolution process. But time has always been ignored in software evolution process modeling, so that we couldn’t analysis or research the time-control problems.For this reason, this thesis using the delay time Petri net to improve the EPMM, in order to add a time-control in modeling. And proposes a model called DTEPMM (Delay Time Evolution Process Meta-Model).On the other hand, it will increase the complexity of the model, so that makes the software evolution process model faces a bigger "state space explosion" problem. It will makes it more difficult to analysis、 measure and verify the system.In order to solve the "state space explosion" problem, we always use the "net reduction" as the main method. At the meantime, it should also keep the reachability> time property、bounded、liveness、fairness and persistency, so that we can analysis the system afterwards.In this thesis, based on different Petri net’s structure, proposed some rules to reduce the DTEPMM on state or transition, and demonstrate the new net keeps the properties of the original net, and make it easier to analysis、measure and verify the system.