Tot Concession Period Of Decision-making Based On Extended Petri Net Operating Public Infrastructure

Decision-making on TOT concession period of operating public infrastructure is the continued theoretical research focus in the field of project finance. It Is a core franchise agreement terms and important parameters, and the core issue in TOT project bidding and negotiating franchise agreements too.If the concession period is too long, it would hurt the interest of the host government and the public. Otherwise, the private investors can't get the expected return on investment; it would results the project failure at last. Existing concession period is determined mainly based on NPV, game theory and Monte Carlo, these three methods can not effectively work on risk NPV, they can not give a the reasonable scope of franchise concession, and hardly support to risk allocation and concession period adjustment, so they just stay in the past similar projects based on cash flow analysis, lacking of a reasonable risk-sharing mechanism and adjustment mechanism. Therefore, how the occurrence of risk events to determine the probability distribution of concession period, and how the occurrence of risk events to determine concession period, has been the key factor for TOT Project Financing.The paper take operating public infrastructure as it's study object, surrounding the decision-making of TOT concession period, proposing three urgent questions: How project risk factors and risk categories to affect decision-making factors; How much project risk factors and risk categories to affect TOT concession period; And what is the probability distribution of NPV and the probability distribution of the concession period based on the above two.Firstly, the paper review the current research on Decision-making of concession period, including decision-making methods, decision-making model, decision factors, such as product pricing, product sales, operating costs, discount rate, franchise value. And then review the applications of colored stochastic Petri nets and fuzzy Petri net, such as project management, organizational decision-making, marketing, artificial intelligence, risk assessment, and other areas of hybrid systems. In risk analysis and assessment, the paper analysis the Operating process and decision factors of TOT, and make a comprehensive analysis of operating public infrastructure projects, analysis all kinds of problems which happened in TOT project. And then identifies all kinds of project risks, builds the risk assessment hierarchical structure, summaries up the core problems and key risks of TOT based on ZOPP. Secondly, the paper makes conclusion of the project risk level, the relative importance of risk factors by building TOT project risk analysis model based on BP neural network and fuzzy expert system model based on fuzzy Petri nets on the basic of risk identification, analysis and evaluation. And then, it analysis the impact of concession period affected by risk factors in use the way of fuzzy hierarchical analysis according to the fuzzy matrix.The paper makes conclusion of the project risk level, the relative importance of risk factors by building TOT project risk analysis model based on BP neural network and fuzzy expert system model based on fuzzy Petri nets on the basic of risk identification, analysis and evaluation. And then, it analysis the impact of concession period affected by risk factors in use the way of fuzzy hierarchical analysis according to the fuzzy matrix.Thirdly, the paper analysis the project NPV and it's probability distribution, and then makes conclusion of the most possible franchise period and it's probability distribution by building TOT concession period of decision-making model based on colored stochastic Petri nets and the NPV model based on Petri nets. These used three sub-models, they are the project risk assessment model of the concession period based on colored Petri nets, the cash flow analysis model based on stochastic Petri nets, and the NPV model based on Petri nets. The first one solves the results of the impact to decision-making factors of franchise period by risk factors and it's occurrence probability through building the process model of decision-making factors of TOT concession period by risk factors. The second one solves the Markov state transition equation of the project cash flows, and then determines the interaction rate between project's revenue CI and CO through their interaction process based on the project cash flow analysis model based on stochastic Petri nets. The third one reflects the interaction between the project's revenue and expenditure in the dynamic project operating process and the impact of them by project risk factors.Finally, the paper obtains the NPV probability distribution and probability distribution of the concession period using computer simulation method in the case with Yunnan Gejiu to Datun highway tunnel. It takes reference for the decision-making of TOT concession period.