Study On Robustness Of The Supply Chain

Supply chain, as an extended enterprise, is a complex and dynamic system. It's complexity and dynamism are further intensified by the global economic integration and market internationalization. The performance of a supply chain is a result of the coordinated operations between companies in the supply chain. Any breakdown on the coordinated operations in the supply chain (i.e. the reliability of the coordinated operations) will largely affect the performance of a supply chain. Hence, effective supply chain management relies on the appraisal and maintenance of the reliability of a supply chain. How to analyze, evaluate, monitor, control and improve the supply chain reliability is gaining more and more attention recently, however, there are still some knowledge gaps. Those knowledge gaps include the study of dynamic margin of safety and the stable state availability, the research of optimal adjustment time of the system.The purpose of this dissertation is to apply reliability engineering methodology to analyze the reliability and robustness of supply chain, and provide theory foundation for research on optimization strategy.Firstly, this dissertation briefly describes the supply chain theory, analyzes the existing risk in supply chain, states the research status on reliability of supply chain and the prospect of managing reliability of supply chain. Then, it studies the supply chain management system as a complex system to confirm the state existing during operating of the system. After that, it conducts a probability analysis on the state which the system located by applying supplement variable method, and establishes the model of distributed parameter system in a form of partial differential equations. Combining C0 ? semigroup theory in the functional analysis, it conducts a dynamic analysis on the established mathematical model. Using this method, it obtains the mathematical expression of the dynamic solution and the steady state solution, and proves the uniqueness, non-negativity and the asymptotic stability of the system solution. This dissertation applies the Matlab tool and uses two-step, three-step Simpson integral equation to imitate the condition of system solution. Then, it adds possible mode of failure and the optimization adjustment state to the system, based on which it has established the distributed parameter system model which is described by partial differential system of equations. Combining the functional analysis C0 ? semigroup theory, it studies the established mathematical model, and obtains the mathematical expression of the dynamic solution system and the steady state solution. It has proven the existing of uniqueness of the system solution, the asymptotic stability of system solution and the system solution. In addition, it has lying the theory rationale for further analysis and the research on the optimization of system.Since the state space selected in this study is the L1 space, it directly obtains the system stable state availability analytic expression after standardizing the system solution. In the expression, it has identified the optimization adjustment time of system (Variable T), which makes the optimization adjustment time of system possible. Therefore, it analyzes and states the optimization adjustment time of system, providing the theory instruction for the enterprises and even the entire supply chain to choose the suitable reliability management strategy.The major contributions and innovations of this paper includes:1) Supplementary variable technique is successfully introduced into the research for the reliability of supply chain. By applying this method, this paper formulates the mathematic model of the system and optimal model for supply chain;2) With the help of Matlab, discretization of the numerical method is adopted to directly simulate the solution of the reliability model for supply chain, and presented the simulation figure;3) Using the theory of semigroup, a strictly mathematical proof is provided for the existence, uniqueness , non-negativity and asymptotic properties of the reliability model and the optimal model for the supply chain. The exponential stability of the solution of the reliability model for supply chain is proved; C0 ?4) By dynamically analyzing the optimal model for the supply chain system, a mathematical expression of availability of the system is obtained corresponding to steady solution of the system. This provides a new approach to solve dynamical stability and dynamical availability of the system and to research the optimal schedule to performing adjustment.