STOCHASTIC COST-VOLUME-PROFIT ANALYSIS WITH A LINEAR DEMAND FUNCTION

In this paper we incorporate a linear demand function to model the price-volume causal relationship into stochastic cost-volume-profit (CVP) analysis. We assume that the objective function is to maximize expected profit; other objective functions are also discussed and compared. A linear stochastic model follows from which probabilistic statements can be easily obtained if the random variables are assumed to be multivariate normal. The basic framework is shown to be a special case of project value maximization where project value is the cash flow of the project discounted for time and risk according to the capital asset pricing model. Moreover, an intertemporal extension that considers inventory is developed. In summary, a new approach to stochastic CVP analysis that incorporates the management decision process in an uncertain environment is developed.     

稳定低生育水平与中国家庭养老关系的再思考

稳定低生育水平不会对家庭养老功能带来负面影响。主要理由是 :1.衡量家庭养老功能的标准已经变化。2 .家庭养老的本质是国家性家庭养老。 3.稳定低生育水平与家庭养老的关系不是单因素对单因素的关系 ,而是系统与系统的关系     

Reading Polanyi in Erbil: understanding socio-political factors in the development of Iraqi Kurdistan

ABSTRACT

The Kurdistan Regional Government emerges out of the chaos of post-Saddam Iraq as a rare positive, providing both political stability and economic growth. However, the outward display masks a more complex domestic settlement where the trappings of the free market coexist with political parties who are significant economic actors. How can this model of development in Iraqi Kurdistan be explained? Turning to the writings of political economist Karl Polanyi, does his thinking on relations between society and economy offer a way to unpack the development? And what does this analysis tell us of prospects for Iraqi Kurdistan?     

分权与旅游治理:基于欠发达地区的实证分析

许多发展中国家实行高度的中央集权,学界对国家政治体制的集权化及其作用已经进行许多有益的探讨,但是对分权的利弊及存在问题却没有深入涉及。本文首先回顾区域治理中的分权理论,提出了一个权力配置、分权控制及其政治规范性的区域治理分析框架,用于描述国家权力在旅游治理中的运行机制,以北部湾旅游发展的实践为例,通过考察中央政府和地方政府、地方企业以及非政府组织在权力治理网络中成长态势,评估广西地方政府在区域旅游治理中的效力,研究发现地方政府在参与决策制定方面仍面临种种困难。     

人力资本投资与地区经济协调发展

人力资本投资在地区经济协调发展中的作用在于:影响经济增长速度,进而影响地区差距;影响地区竞争优势,进而影响地区分工格局;影响落后地区贫困人口的脱贫及经济增长方式,从而影响社会的稳定和谐和可持续发展的实现。从人力资本投入总量及条件等方面看,东中西部人力资本投资情况存在较大差异,它影响了地区经济的协调发展。必须注重全局,制订人力资本投资规划;在强化区域投资中向人力资本投资倾斜;整合落后地区教育资源,加大中西部地区基础教育的投入,开放教育市场,引进外部资金,增强中西部地区人力资本积累能力;增加农村公共卫生特别是中西部农村的公共卫生投入,全面提升落后地区人力资本质量,促进地区经济协调发展。     

Master Production Rescheduling Policy in Capacity-Constrained Just-In-Time Make-To-Stock Environments

This paper describes a simulation experiment to evaluate the relative effectiveness of rescheduling policies in capacity-constrained, just-in-time (JIT) make-to-stock production environments. Three performance measures were analyzed: average finished goods inventory, total units of sales lost, and a measure of schedule instability. Among the three loading methods we studied (level loading, front loading, and back loading), none was superior across all three performance measures. Level loading was the most robust, while back loading had an interaction effect with forecasting model and capacity level. Time fence scenario was found not to be as significant a factor in system performance as reported by previous research. Once an acceptable time fence scenario is selected, attempts to optimize this factor do not appear to offer significant improvement. It was found that higher demand variation, larger forecast errors, and tight capacity lead to the degradation of system performance. Judicious use of slack capacity helps a system to incorporate the periodic schedule changes typical of JIT systems.     

A Stochastic Goal Program for Employee Scheduling*

Deterministic goal programs for employee scheduling decisions attempt to minimize expected operating costs by assigning the ideal number of employees to each feasible schedule. For each period in the planning horizon, managers must first determine the amount of labor that should be scheduled for duty. These requirements are often established with marginal analysis techniques, which use estimates for incremental labor costs and shortage expenses. Typically, each period in the planning horizon is evaluated as an independent epoch. An implicit assumption is that individual employees can be assigned to schedules with as little as a single period of work. If this assumption violates local work rules, the labor requirements parameters for the deterministic goal program may be suboptimal. As we show in this research, this well-known limitation can lead to costly staffing and scheduling errors. We propose an employee scheduling model that overcomes this limitation by integrating the labor requirements and scheduling decisions. Instead of a single, externally determined staffing goal for each period, the model uses a probability distribution for the quantity of labor required. The model is free to choose an appropriate staffing level for each period, eliminating the need for a separate goal-setting procedure. In most cases this results in better, less costly decisions. In addition, the proposed model easily accommodates both linear and nonlinear under- and overstaffing penalties. We use simple examples to demonstrate many of these advantages and to illustrate the key techniques necessary to implement our model. We also assess its performance in a study of more than 1,700 simulated stochastic employee scheduling problems.     

Solution Procedures for the Lot-Streaming Problem

Lot streaming is the process of splitting a job into sublots so its operations can be overlapped and its progress accelerated. We present a computationally efficient procedure for solving the m-machine, two-sublot problem, and we discuss the bottleneck insights that emerge from the analysis. We also examine heuristic approaches for more than two sublots and discuss computational results for these procedures.     

Resource Flexibility Issues in Multistage Manufacturing

We test the situational impact of two types of resource flexibility, machine flexibility and labor flexibility, in a material requirements planning (MRP)-driven production system. Machine flexibility has not been treated in prior multistage research, only labor flexibility. Machine flexibility is closely related to a plant's positioning strategy. A process-focused plant opts for considerable machine flexibility by choosing general-purpose equipment. Resource flexibility, if effective, can be an attractive alternative to two other types of buffers, inflated inventories and costly capacity cushions. Our simulation results, using factor settings established earlier by a panel of managers, show that resource flexibility is indeed an effective buffer against uncertainties such as end-item demand variability, capacity bottlenecks, equipment failures, and yield losses. Machine flexibility is especially helpful in environments characterized by high uncertainties, tight capacities, and large lot sizes. Worker flexibility has a similar, but less dramatic, impact. Benefits are most striking with customer service, rather than with inventory or labor productivity. Finally, we show that simultaneous introduction of both machine and labor flexibility yields only marginal improvements over either kind of flexibility alone.