Push-Kanban – a kanban-based production control concept for job shops

Job-shop production in an individual and small-batch manufacturing environment demands producing simultaneously different products in many customised versions and in small numbers. The associated variability of the time-phased work content leads to a high degree of complexity and turbulence in the manufacturing process of such a production type. Therefore, production control becomes significantly more complicated, and many theories on how to cope fail in the real world. Despite the many technological and conceptual advances in the field of job-shop control over the past few decades, there is still a remarkable lack of practical control approaches for job-shop production. For this reason the Push-Kanban production control concept will be introduced in this article. It combines robust push scheduling along with a kanban-driven, decentralised inventory control mechanism to create a holistic control approach, integrating all production control tasks. Thus, it offers a feasible option for controlling job-shop production in industrial practice. This article examines the effectiveness of the concept by means of a simulation study based on real data.     

A routine-based framework implementing workload control to address recurring disturbances

Abstract

This research focuses on responsiveness in high variety manufacturing environments. To achieve it, the article proposes to develop Dynamic Response Capabilities (DRCs) of the manufacturing system defined as the abilities to readjust the planned operating parameters of workload, capacity, and lead time, in the wake of disturbances. To inform their development, built on the Workload Control theory, a routine-based framework is proposed. The framework supports an integrated approach for the implementation of adaptive decision-making routines for workload, capacity, and lead time readjustments at different stages in the order fulfilment process. Findings from two empirical cases show the appropriateness of the framework to develop and utilise DRCs in different settings of disturbances. Results of a simulation study, with one of the case companies, also shows the effectiveness of the framework to drive performance improvements in presence of recurring disturbances leading to demand variability.     

Burnout and impaired cognitive functioning: The role of executive control in the performance of cognitive tasks

Abstract

Burnout patients often report deficits in cognitive control, and there is a need to understand the processes involved. Drawing on recent findings, we hypothesized that emotional exhaustion and task-related demands on executive control would interact in predicting performance in tasks requiring the updating and monitoring of working memory as well as the inhibition of prepotent (dominant or automatic) responses. In accordance with recent conceptualizations of burnout, we focused on emotional exhaustion as the core symptom of burnout. The sample comprised 81 employees recruited from nursing homes for elderly care in Germany, who participated in a laboratory study involving cognitive tasks. Based on a median split, participants were divided into two groups: those with high burnout and those with low burnout. In line with our hypotheses, the high exhaustion participants performed less well than those with low exhaustion only when tasks put high demands on their executive control. As predicted, high levels of emotional exhaustion were associated with more errors and longer reaction times when demands on executive control were high, whereas no performance differences were found when both tasks put low demands on executive control. The implications for practice are discussed.     

Sources of occupational stress: An examination of British prison officers

Abstract

The purpose of this paper is to identify the major sources of occupational stress experienced by British prison officers and to examine their effects on overall job stress and job satisfaction. Eighty-one officers from HM Prison, Maidstone, took part in a questionnaire study, and three main findings emerged. First, lack of stiff and resources were ranked as the most likely sources of stress, and areas of the prison where confrontations with inmates were most likely to occur were ranked as the most stressful locations. Second, officers who reported the highest levels of job stress overall had the lowest job satisfaction and the greatest wish for more emphasis on control and security of inmates. Third, when the sources of stress were factor-analysed and used to predict overall job stress and job satisfaction, using multiple regression, the sìngle most important predictor of job stress was found to be the factor labelled 'confrontations with inmates' and, for dissatisfaction with the job, it was 'poor morale and resentments'. The paper discusses the theoretical implications of the findings.     

企业进入权、组织控制与跨国公司专用性投资激励

论文从国际生产组织控制视角,将Rajan和Zingales^[1]进入权思想融入国际生产与贸易模型中,研究跨国公司专用性投资激励问题。研究发现,在进入权的机会控制和数量调整机制作用下,跨国公司通过限制进入、替代竞争来激发当地供应商做出事前定制投资、分摊投资和事后最优专用性投资,确保获取合意投入品和预期最大化利润。当前,政府要引导外向企业致力于微观企业主体的制度建设和组织能力培养,构建起中国国际生产网络及其组织机制,为推进对外直接投资和企业国际化经营提供微观保障。     

The deterministic EPQ with partial backordering: A new approach

Several authors have developed models for the EOQ when only a percentage of stockouts will be backordered. Most of these models are complicated, with equations unlike those for the EOQ with full backordering. In this paper we extend work by Pentico and Drake [The deterministic EOQ with partial backordering: a new approach. European Journal of Operational Research 2008; in press] that developed equations for the EOQ with partial backordering that are more like those for the EOQ with full backordering to develop a comparable model for the EPQ with partial backordering.     

公司治理、控制权性质与审计定价

借鉴Simunic的审计定价模型,构建关于审计定价影响因素的多元线性回归方程,并以沪深两市上市公司2007年数据为研究对象,对股权结构、公司治理与审计定价之间的关系进行实证检验.研究结果表明,总体而言,公司治理因素对中国上市公司审计定价的解释力有限,说明中国会计师事务所在决定审计收费时对被审计单位的公司治理因素考虑较少.具体而言,终极控制人为政府的上市公司审计费用较低,股权集中度、管理层持股比例与审计定价之间大体上呈U型关系,即股权适度集中和管理层适度持股最有利于降低审计定价,进一步的研究发现,管理层持股比例与审计定价的U型关系仅存在于非国有控股公司样本中.研究还发现,中国会计师事务所在确定审计费用时会结合公司控制权的性质考虑风险因素时审计定价的影响.     

基于效率的企业资源配置部门剥离条件研究

研究企业中资源配置部门的剥离条件问题.首先,建立了企业资源配置部门的控制模型,并定义了效率概念;然后,分别对企业中的单一资源配置部门和多资源配置部门的剥离条件进行分析,给出判断这2种资源配置部门的剥离分界点公式.由此得到结论:完全竞争市场中,企业根据剥离分界点,把要配置的资源分为稀缺程度较高和稀缺程度较低2类,前者应由企业资源配置部门来配置,后者应由市场来配置;如果市场配置某种资源的效率低于企业部门的配置效率,则企业部门是市场的替代,反之,市场则替代企业部门.     

Optimal Ordering Policies for Stochastic Inventory Problems with Observed Information Delays

Information delays exist in an inventory system when it takes time to collect, process, validate, and transmit inventory/demand data. A general framework is developed in this paper to describe information flows in an inventory system with information delays. We characterize the sufficient statistics for making optimal decisions. When the ordering cost is linear, the optimality of a state‐dependent base‐stock policy is established even when information flows are allowed to cross over time. Additional insights into the problem are obtained via a comparison between our models and the models with stochastic order lead times. We also show that inventory can substitute for information and vice versa.     

Inventory‐Based Dynamic Pricing with Costly Price Adjustment

We study an average‐cost stochastic inventory control problem in which the firm can replenish inventory and adjust the price at anytime. We establish the optimality to change the price from low to high in each replenishment cycle as inventory is depleted. With costly price adjustment, scale economies of inventory replenishment are reflected in the cycle time instead of lot size—An increased fixed ordering cost leads to an extended replenishment cycle but does not necessarily increase the order quantity. A reduced marginal cost of ordering calls for an increased order quantity, as well as speeding up product selling within a cycle. We derive useful properties of the profit function that allows for reducing computational complexity of the problem. For systems requiring short replenishment cycles, the optimal solution can be easily computed by applying these properties. For systems requiring long replenishment cycles, we further consider a relaxed problem that is computational tractable. Under this relaxation, the sum of fixed ordering cost and price adjustment cost is equal to (greater than, less than) the total inventory holding cost within a replenishment cycle when the inventory holding cost is linear (convex, concave) in the stock level. Moreover, under the optimal solution, the time‐average profit is the same across all price segments when the inventory holding cost is accounted properly. Through a numerical study, we demonstrate that inventory‐based dynamic pricing can lead to significant profit improvement compared with static pricing and limited price adjustment can yield a benefit that is close to unlimited price adjustment. To be able to enjoy the benefit of dynamic pricing, however, it is important to appropriately choose inventory levels at which the price is revised.