مطالعه برای روش تجزیه و تحلیل جریان کاری برای مدت زمان بازه و اندازه گیری فرکانس مبتنی بر شبکه پتری

Aim: Study formal methods on workflow analysis for time interval and frequency measuring, which can provide quantitative assessment and be automatically implemented on computer; Methods: Capitalize the basic theory of Petri-net to extract workflow model, illustrate the process of time interval and frequency measuring, assert whether the result is right or not, provide optimal path selection, record the numerical value of testing result until the end of the test; Results: Relying on workflow analysis, not only automatic measuring is implemented, also the validation of the process is offered; exemplify the practical situation and summarize the key points of practical experiments. Conclusion: The presented Petri-net based method, in principle, can be applied to key equipments, such as equipments in the fields of spaceflight, nuclear security control, and testing meters in massive scale projects, builds the basic theoretical foundation for automatic test.

With the significant development of information and digital technology, the requirement of test on massive scale systematic equipments, such as those crucial devices used on airplanes, space shuttles and nuclear projects, is growing rapidly, so the authentication of the testing process is extremely required besides the accuracy and reliability of testing results, under which situation the traditional handprogrammed planning has been out of date. It is reported that due to the misuse of a single programming statement in the testing stage before launching, American space shuttle Columbia crashed, leading onboard crew killed, and loss of billons of dollars. Accidents like this are certain to raise the care of implementing automatic test on key equipments to avoid accidents and sequent huge loss. This paper proposes a Petri-net based analysis method for time interval and frequency measuring, which aims to provide verbose and exact steps and scientific benchmark for automatic implementation. In the remainder, this paper firstly introduces the application background and manual operation procedure of time-interval and frequency meter, and analyzes the application configuration. Secondly, introduces the Petri-net theory and key points of workflow analysis, mainly focus on the process of time interval and frequency measuring method using Petri-net model. At last, the paper concludes with the summary of the presented method.

This paper introduces a Petri-net model for time interval and frequency meter and argues its significance. Due to the pervasive utilization of time interval and frequency meter, especially for selfcontrol function of weapon systems, self-test and time scales verification for information-based command procedure, we many a time use the method of “requirement analysis — P model extraction — programdesign — control encoding — command implementation”, to design and rectify time interval and frequency meter, consequently significantly raise success ratio.Petri-net based workflow analysis method can be applied to instruments design and very important workflow control program, can also be used in reliability analysis of some workflow models.However, still furthermore works are required for the quantitative reliability analysis problem.