Analysis of an Inventory System for Items with Price-Dependent Demand and Time Dependent Three-Parameter Weibull Deterioration Function

In this research work we propose a mathematical model of an inventory system with time dependent three-parameter Weibull deterioration and price-dependent demand rate. The model incorporates shortages and deteriorating items are considered in which inventory is depleted not only by demand but also by decay, such as, direct spoilage as in fruits, vegetables and food products, or deterioration as in obsolete electronic components. Furthermore, the rate of deterioration is taken to be time-proportional, and a power law form of the price dependence of demand is considered. This price-dependence of the demand function is nonlinear, and is such that when price of a commodity increases, demand decreases and when price of a commodity decreases, demand increases. The objective of the model is to minimize the total inventory costs. From the numerical example presented to illustrate the solution procedure of the model, we obtain meaningful results. We then proceed to perform sensitivity analysis of our model. The sensitivity analysis illustrates the extent to which the optimal solution of the model is affected by slight changes or errors in its input parameter values.

Discount Rate of China’s New Energy Power Industry

Under the dual pressures of energy crisis and environmental pollution,China’s new energy power industry has become a focal point for environmental management and requires greater investment.In this context,as a significant input of investment projects,discount rate requires a well-calibrated evaluation because new energy power investment projects are highly capital intensive.The main objective of this paper is to evaluate the discount rate of China’s new energy power industry.First,we use Moving Average to correct the parameters of capital asset pricing model(CAPM)and weighted average cost of capital,which extends the literature on the avoidance of CAPM noise information problem.Second,we study the industry-level annual discount rates of mainly China’s new energy power industries,including hydropower,nuclear power,wind power,and photovoltaic power industries for the period of 2014-2019.The results show that discount rates in China’s new energy power industries evolved differently between the years of 2014-2019 with average annual discount rates being 7.56%,5.83%,5.60%,and 8.64%,for the hydropower,nuclear power,wind power,and photovoltaic power industries,respectively.In 2019,the four annual discount rates were highest for the photovoltaic power industry(8.66%),followed by hydropower(7.17%),wind power(5.72%),and nuclear power industry(5.26%).Forecasting to 2020 from the 2019 evaluation base period,the discount rates are 6.37%,5.00%,6.57%,and 9.05%for the photovoltaic power,hydropower,wind power,and nuclear power industries,respectively.Under the different capital structures,their forecasts for the photovoltaic power,hydropower,wind power,and nuclear power industries in 2020 are,respectively,within[4.35%,9.24%],[3.92%,7.10%],[4.58%,10.40%],[5.46%,14.81%].We also discussed more details on capital structure and forecast period of discount rates for China’s new energy power industries.Our analysis shows that it is necessary to establish a new energy power industry database and steadily promote the implementation of policies.

考虑参考价格效应的库存路径与定价问题

针对客户有价格策略型行为下的供应商库存路径与定价问题(inventory routing and pricing problem,IRPP),通过将参考价格效应嵌入产品需求价格函数中,以供应商总利润最大化为目标,构建考虑参考价格效应的IRPP优化模型,设计改进的粒子群算法进行求解。通过3组不同规模的算例验证本文模型与算法的适用性和有效性。计算结果显示,考虑参考价格效应不仅有助于降低产品定价(约9%)和提升客户感知收益,而且能够降低零售商的产品总库存(约22%)、仓储资源占用成本和库存持有成本,从而提高供应商总利润(约5%)。敏感性分析结果显示:受客户记忆参数减小和增益系数增大的共同影响,供应商总利润会明显增加;受客户记忆参数和损失系数增大的共同影响,供应商总利润会迅速下降。研究结论可为电商环境下客户有价格策略型行为下的供应商IRPP优化提供决策支撑。

全渠道电商库存路径及定价问题优化研究

针对全渠道模式下电商库存路径及定价问题,考虑各前置仓需求不确定因素,本文提出一种按照不同售卖渠道的商品差异化定价策略,通过设置电商关于需求不确定风险态度的保守系数,构建以总利润最大化为目标的混合整数非线性鲁棒优化模型,并设计自适应模拟退火粒子群算法进行求解。选取含有10个和20个前置仓的两组算例,验证本文模型算法的适用性和有效性。实验分析结果显示,相比于统一定价,差异化定价可以提高电商总利润分别约5%和6%。敏感性分析结果表明,提升线上客户的线下购物体验以增加线上自提渠道客户数量,并组织线上营销活动以提高线上客户对电商促销努力的敏感度,能给电商带来更高的利润;掌控未来市场波动风险并准确预测需求信息以降低电商保守系数和需求最大偏离系数,亦可提高电商总利润。研究结论可为电商制定前置仓库存配送路径策略与各渠道商品定价方案提供参考。

双渠道供应链下易腐品的库存和定价决策

以现实易腐产品供应链为背景,研究单一零售商和单一供应商组成的双渠道供应链模型,即供应商可通过直接在线渠道和间接零售渠道销售易腐产品,除了产品数量下降外,产品质量也会随着时间的推移而下降,同时,产品质量的下降会影响零售渠道的需求率。分别建立集中式和分散式两类模型,并提出相应算法求解最佳价格、订购频率和订购周期等。结果显示,分散式的供应链不仅会侵蚀两家公司的利润,并且产品的浪费率也较高。通过采用收入分享和二部定价法的方式能够协调供应链,减少供应链的总浪费率。同时,随着产品劣化率的提高,两家公司会更倾向于进行供应链协调,协调合同对零售商利润的提升更为显著。在模型扩展部分考虑直接渠道的交货时间,结果表明,分散式模型的供应商会投入更多资金以缩短交货时间。

A LIMITED ORDER CAPACITY STOCHASTIC INVENTORY MODEL WITH A FIXED COST FOR ORDER: THE DISCOUNTED CASE

This paper considers a single-item, periodic-review inventory model with linear ordercosts, a convex function representing expected one-period costs, nonegative i.i.d. demandsand a fixed cost for order. Stockouts are backordered. All data are stationary Both finiteand infinite horizon problems are treated.

A Stochastic Flight Problem Simulation to Minimize Cost of Refuelling

Commercial airline companies are continuously seeking to implement strategies for minimizing costs of fuel for their flight routes as acquiring jet fuel represents a significant part of operating and managing expenses for airline activities.A nonlinear mixed binary mathematical programming model for the airline fuel task is presented to minimize the total cost of refueling in an entire flight route problem.The model is enhanced to include possible discounts in fuel prices,which are performed by adding dummy variables and some restrictive constraints,or by fitting a suitable distribution function that relates prices to purchased quantities.The obtained fuel plan explains exactly the amounts of fuel in gallons to be purchased from each airport considering tankering strategy while minimizing the pertinent cost of the whole flight route.The relation between the amount of extra burnt fuel taken through tinkering strategy and the total flight time is also considered.A case study is introduced for a certain flight rotation in domestic US air transport route.The mathematical model including stepped discounted fuel prices is formulated.The problem has a stochastic nature as the total flight time is a random variable,the stochastic nature of the problem is realistic and more appropriate than the deterministic case.The stochastic style of the problem is simulated by introducing a suitable probability distribution for the flight time duration and generating enough number of runs to mimic the probabilistic real situation.Many similar real application problems are modelled as nonlinear mixed binary ones that are difficult to handle by exact methods.Therefore,metaheuristic approaches are widely used in treating such different optimization tasks.In this paper,a gaining sharing knowledge-based procedure is used to handle the mathematical model.The algorithm basically based on the process of gaining and sharing knowledge throughout the human lifetime.The generated simulation runs of the example are solved using the proposed algorithm,and the resulting distribution outputs for the optimum purchased fuel amounts from each airport and for the total cost and are obtained.

允许缺货下的生鲜产品多级库存与定价决策

为了探讨多级生鲜供应链的库存与定价决策,在允许缺货的条件下,以单供应商、多分销商和多零售商组成的三级生鲜供应链系统为研究对象,考虑新鲜度因素并构建符合实际产品特性的新鲜度函数、保鲜投入成本影响的变质损耗函数和受新鲜度、价格、库存水平3因素影响的需求函数。针对零售商降价销售的情况,根据临界库存得到订货量与销售价格之间的数量关系,建立以供应链整体利润最大化为目标的三级库存优化控制模型。运用免疫算法求解得到最优库存与定价决策,通过算例分析验证了模型的有效性。研究结果表明:采取降价策略、制订合理的价格、维持稳定的库存水平、适当的保鲜投入能有效减少变质损耗,提高销售量和销售利润。

联合协调下分销系统价格折扣问题研究

研究由单一分销商和单一零售商组成的分销系统中价格折扣策略问题·假设顾客需求是随机的价格弹性需求,在分销系统价格折扣策略的制定过程中,一切决策由一个中心决策者在掌握全部有价值信息的情况下做出,其目标是在满足分销商和零售商个体理性约束条件下使整个分销系统的利润最大·结果表明,在随机的价格弹性需求条件下,由分销商提供的价格折扣能够同时提高分销商和零售商的利润,最后用一个算例来说明模型的应用效果·

一类供应链的Stackelberg主从对策问题研究

本文研究了供应链中的一般订货模式和协调模式 ,提出了一类供应链Stackelberg主从对策问题 ,卖方作为主方给出最小补充期策略 ,买方作为从方以最优库存策略响应。考虑一致价格折扣弥补买方的库存成本增加 ,以及买方的库存成本合理化 ,建立买方需求确定下的卖方成本优化模型。最后 ,应用遗传算法对石油分销系统Stack elberg主从对策问题离线仿真计算 ,得出Stackelberg主从对策均衡解。

考虑价格折扣的两级供应链库存模型

该文把供应链资金流区分为内部资金流和外部资金流,对供应链管理中的库存费用流动过程进行了分析;建立了考虑价格折扣的两级供应链库存数学模型,并运用一种简单而有效的逼近方法求出了模型最优解,确定了供应链中各企业的最佳订货批量;最后用数值实例说明了该方法的有效性。

基于多级折扣价格的易逝品订货策略研究

基于价格折扣条件下的报童模型,研究了分销商面向折拐的需求价格曲线。采用呈等差数列下降的多级折扣价格销售产品,以期望利润最大为目标,给出了求解最优折扣次数的算法,进而得到相应的分销商最优订货量。与需求价格曲线的斜率b不变时相比较,b增大对最优订货量无显著影响;b减小对最优订货量有显著影响。

可控提前期下复杂部分短缺量拖后的库存模型

顾客在缺货时会根据等待时间、价格折扣等因素决定是否等待.基于此,建立了可控提前期下考虑部分短缺量拖后率随等待时间和价格折扣变化的库存模型,然后分析了提前期决策对总成本、订货批量决策和价格折扣决策的影响.结果显示:压缩提前期只有满足一定条件才能降低总成本;提前期决策会通过丢单成本和拖后成本的变动来影响最优订货批量,当减少的拖后成本和丢单成本大于压缩费用时,最优订货批量随提前期的压缩而减少,否则随提前期的压缩而增加;压缩提前期并不直接影响最优价格折扣,最优价格折扣和订货批量随提前期变化的趋势相同.

季节性商品的促销定价模型与算法

研究了季节性商品在促销前提下的定价问题.在综合考虑季节性商品的销售特点、销售折扣率、商品库存、商品周期衰退、商品价格等问题的基础上,建立了以利润损失最小为目标的动态定价模型,以商家需处理的货物量为约束条件,基于改进遗传算法和粒子群算法,找到了成本最优的商品定价.并通过仿真,分析了商品定价对利润损失的影响,为大中型企业的促销决策提供了重要依据.

基于价格折扣的易腐物品供应链库存的协作控制研究

库存作为供应链上的重要环节,越来越受到企业界和学术界的关注。但是目前对于供应链库存协作控制的研究大多假设库存货物能无限期存放,很少考虑产品在存贮过程中发生的变质、减值等情况,因此现有的以一般产品为对象的供应链库存协作控制研究并不适用于易腐物品。本文以易腐物品为对象,研究如何用价格折扣的激励方式来实现对易腐物品二级供应链库存的协作控制,从而最终达到优化供应链库存的目的。

消费者预测行为对供应链牛鞭效应和零售商库存的影响分析

考虑一个供应商和一个零售商组成的两级供应链,建立了价格敏感的需求函数模型,分析价格波动下消费者的价格预测行为对供应链牛鞭效应和零售商库存的影响。研究表明,消费者的价格预测行为有助于减小牛鞭效应和零售商库存,特别地当零售商需求预测不平滑时,消费者的价格预测行为对抑制牛鞭效应和减小零售商库存的作用更为显著。

短生命周期产品的三种库存模型的比较

讨论短生命周期产品库存模型,考虑无形变质因素,并假定无形变质率与需求率成反比关系.在线性需求和常数生产率的条件下,假设,若需求率为1,则视作产品的市场生命周期结束.并且,在产品生命周期的前期不存在缺货的情况下,给出了短生命周期产品分别在理想状态、允许缺货以及价格折扣导致需求率变化等3种状态下的库存模型,最后在相同参数条件下对这3种模型进行比较,找出了单位时间内平均总成本最小的最优库存模型,厂商可以根据自身的情况选择合适的库存策略.

带有快速反应策略供应链系统的补偿策略研究

过长的订购提前期往往使得零售商订货决策感到困难.快速反应策略能使零售商在获得更多更准确的市场需求信息后,调整订购量而提高收益.但是快速反应策略并不一定使供应商的利润也提高.有文章指出只有低的服务水平才能使两者利润同时提高,因而这种方法在工业应用中是不一定可行的.补偿策略是一种广泛应用的方法,能够提高产品的客户服务水平,因而研究了补偿策略在快速反应供应链系统中的作用.在某些条件下,在快速反应供应链系统中,补偿策略能使零售商与供应商一方的收益不变或者提高,另一方的收益有所提高,即Pare to提高.还研究了引进补偿策略后,供应链系统的最优解及期望卖出量、期望缺货量和期望残余量的变化情况.

多供应商、多销售商的两级供应链库存模型研究

研究多个供应商、多个销售商组成的两级供应链的库存系统,在具有价格弹性的市场需求、允许供应商和销售商产生缺货的条件下,针对有无价格折扣的两种情况,分别建立了供应商、销售商各自的库存模型;结合满足供应商和销售商Pareto有效性,建立了含价格折扣的供应链系统整体盈利最大的库存模型。

考虑零售商策略性库存的双渠道供应链定价及协调

针对双渠道供应链环境下零售商将前期采购的部分产品作为策略性库存用于后期销售的情形,建立了制造商为主方的两周期Stackelberg动态博弈模型,分析了零售商持有策略性库存对双渠道供应链成员定价决策的影响。研究结果表明,零售商可以通过持有策略性库存影响制造商的批发价格决策,进而影响传统零售渠道和电子直销渠道之间的零售价格竞争。特别地,当单位库存持有成本较小时,持有策略性库存能够增加零售商利润。同时,为了缓解渠道冲突和双重边际化问题,构造了基于电子渠道直销价格的批发价格折扣和固定转移支付组合契约。最后,通过数值分析,验证了此种组合契约同时协调零售商策略性库存决策和双渠道供应链成员两周期定价决策的有效性。