Research On System Dynamics Simulation And Operational Efficiency Evaluation Of Coal Service Supply Chain

China's coal industry has experienced changes of ten years “golden period” to “recession period”.With serious pressure from environmental protection,the government put forward higher requirements for the development of the coal industry.Earning price differentials by trading in the past has been unable to meet the long-term development needs of the coal industry.Since coal enterprises generally value production than circulation,supply chain management of coal production has been a hot topic in enterprise management practice and academic research.But based on Chinese pattern of coal transportation namely “from north to south,west to east”,coal circulation costs accounted for high proportion in coal prices.Under the policy request of supply side reform,the coal enterprises should strengthen the management of supply chain circulation.Coup led with the global economic servicizing development,China's coal industry development has the c haracteristics of service-oriented transformation.The research of coal service supply chain will further improve the academic research system of coal supply chain,also provide a new idea for the servicizing development for the coal industry.Based on consulting a large number of domestic and foreign literature and related books,the thesis divides the coal supply chain from the perspective of the service,and puts forward the definition and structure of the coal service supply chain.Using the coal service supply chain consists of one large domestic supply chain management company and its downstream as an example,the thesis models the coal service supply chain with system dynamics to visualize its operation mechanism,establishes the evaluation index system to evaluate the efficiency of the supply chain operation,discover the existing problems,and puts forward the management optimization measures.The first chapter analyses the background and significance of the study,puts forward the necessary to strengthen supply chain management during coal circulation under background of global servitization,and gives the methods needed,technology route and structure o f the research.The second chapter analyzes the origin and development of service supply chain,its difference with manufacturing supply and the coal supply chain research review,which found that the existing coal supply chain research generally treat co al production enterprise as the core enterprises and the downstream extension as the research object,only a few coal supply chain researches treat the non-coal production enterprises as core enterprises,lesser highlight service flow.The third chapter introduces the concept of industrial commons,and uses causal analysis of system dynamics to clarify the positive feedback relationship between coal service supply chain and coal industrial commons.It analyzes the current situation of enterprise practice o f coal supply chain management.On the basis of dividing the coal supply chain according to whether the leading enterprise is a large state-owned coal enterprise,the definition of the coal service supply chain is given.Based on the theory of self-organization,it analyzes the complex characteristics and dissipative structure attributes of coal service supply chain system,and analyzes the characteristics of the unity of opposites between self-organization and herter-organizations.It also analyzes the operation mode and main characteristics of the coal service supply chain.The fourth chapter discusses the feasibility of using system dynamics to build coal service supply chain model,and set the boundary and the assumption of modeling.According to the four node enterprises of coal supply chain service,namely coal users,supply chain management service providers,coal suppliers,micro-professional service providers,it divides the whole model into four sub-systems which are integrated to the initial model of coal service supply chain.Then,their causal relationship is sequentially analyzed.Based on the causal relationship diagram,their system flow graphes are drawn,so as to get the initial system dynamics model of coal service supply chain.In the fifth chapter,according to the data obtained from the investigation,the equation between variables is determined and the validity of the equation is tested.It also analyses the initial results from four aspects namely logistics,information flow,service ability flow and cash flow by running the constructed model.Through integrated use of sensitivity analysis,causes strip,test functions,model refinements etc tools and methods,it explores the operation mechanism of the four streams,finds the shortcomings and gives respectively policy recommendations.The sixth chapter builds operation efficiency evaluation index system for coal service supply chain also from the four aspects namely logistics,information flow,service ability flow and cash flow.Using AHP to determine the weight of each index,it uses the fuzzy comprehensive evaluation method to evaluate the operational efficiency,concludes the operational level of coal service supply chain and the evaluation value of the four flows,points out that we s hould strengthen management of the logistics,information flow and capital flow.The seventh chapter summarizes conclusions and innovation points of the research,and points out the shortcomings of the thesis.The main conclusions are as follows:(1)The inventory in the coal service supply chain has the phenomenon of amplification,oscillation and phase lag.Its inventory fluctuation is mainly affected by coal price,coal production strategy and users' purchasing strategy,and different from the common bullwhip effect,it has different characteristics from the two perspectives of storage location and ownership.The fluctuant curves of coal users' inventory and consumption show “inverted image” characteristic,and the fluctuant curves of actual coal ordering speed and coal receiving rate show obvious phase lag as a result of delay.Through sensitivity analysis,it can be concluded that coal users can reduce inventory effectively by appropriately reducing covering time of safety inventory and prolonging inventory adjustment time.(2)Supply chain management service provider needs to control the time of entire service process under the coal users' acceptable scope.In order to maintain the response speed to the order and keep the gap between order processing time consuming and target delay time low,it has a low service capacity utilization rate and high idle probability.Through simulation,we can find the critical time point for the enterprise to recruiting according to its delay target and actual order.(3)Through discussing two cases according to if service capacity of professional service providers namely port is variable,the thesis puts forward that the delay time of the stage is not easy to change by human power efficiently with the case of fixed service capacity,supply chain management service provider should choose more efficient transportation routes for orders requiring short delivery time when the port is busy.With variable service capacity,the port can shorten the time gap between actual delay time and target delay time by improving the automation and integration level of service system,flexibly adjusting the number of opened berths,service hall windows,service personnel.(4)In the light of frequent receivables in supply chain,through the simulation of two scenes whether supply chain management service providers involved or not,it concludes that with supply chain management service providers involved coal mine will achieve rapid return of capital,coal users will receive the order quantity tha t contract required,supply chain management service providers will also obtain appropriate service revenue.It contributes to the supply chain capital' flowing without hindrance.(5)Through the construction of operation efficiency evaluation system for t he coal service supply chain and the evaluation for it using AHP and fuzzy comprehensive evaluation method,the thesis reaches the comprehensive evaluation value of 84.77 points,the logistics evaluation index value of 78.13 points,the flow of information evaluation index value of 73.52 points,service ability flow index evaluation value of 90.2 points,capital flow index value of 81.73 points,indicating the overall efficiency of the supply chain is on the medium level,but the evaluation results of logistics,information flow and capital flow are lower,and need more focus on strengthening the optimization management.The innovativon points of this thesis are as follows:(1)The structure model of coal service supply chain is constructed.O n the basis of status analysis of the coal service supply chain management,using the service dominant logic theory and the theory of supply chain management defines the coal service supply chain according to different scales and function classifications.Put forward structure model of the coal service supply chain including four main enterprises namely coal users,supply chain management service providers,coal suppliers,micro-professional service providers which is different from the traditional ones.Analyzed its five characteristics,and explored its mechanism of constructing and operating using self-organization theory.These provide the foundation for the establishment of system dynamics model for coal service supply chain.(2)The system dynamics model of coal service supply chain is constructed.Through systematic analysis of the operation mechanism of coal service supply chain,it set up a system dynamics model including coal user subsystem,supply chain management provider subsystem,coal supplier subsystem,micro-professional service provider subsystem.From the cut-in points such as logistics,information flow,service ability and capital flow and combining use of tools and methods namely sensitivity analysis,causality decomposition diagram,test functions,model improving,it made simulation analysis of the case study from aspects of inventory management strategy,order and service capacity management,capital flow management with Vensim software,and then put forward management suggestions.(3)The evaluation index system of coal service supply chain operation efficiency based on analytic hierarchy process(AHP)and fuzzy comprehensive evaluation method is constructed.First of all,based on the SD model has been set up,the evaluation index system for coal service supply chain operation efficiency is constructed from four aspects,that is logistics,information flow,service ability flow and capital flow.Secondly,according to the investigation and interview,and running results of the SD model,it realizes the application of evaluation model of the coal service supply chain operation efficiency.