Order Promising and the Master Production Schedule*

Previous research on material requirements planning (MRP) systems has rarely considered the impact of the master production scheduling method used to promise customer orders and to allocate production capacity. Based on a simulation study of an MRP environment, we show that the correct selection of a master production schedule (MPS) method depends on the variance of end-item demand. In addition, we find evidence that the effectiveness of a particular MPS method can be enhanced by holding buffer inventory at the same level in the product structure as in the MPS.     

Laying the foundation for a global body of knowledge in public relations and communications management

An internationally recognised body of knowledge is both possible and necessary for the future success and professionalisation of public relations. Through extensive content analysis of 31 credential schemes, education frameworks, and scholarly articles produced across six continents, the Global Alliance for Public Relations and Communications Management has developed a foundational list of knowledge, skills, abilities and behaviours (KSABs), which entry and mid/senior-level practitioners across the world should possess. This study and list of KSABs is laying the foundation for development of an internationally accepted framework which professional associations and academic institutions across the world will be able to use to benchmark professional credentials and curriculum outcomes.     

数控加工与编程数字化教学资源建设

为培养高职数控技术专业学生的数控加工与编程能力,通过调研典型制造型企业,以其岗位能力需求为基础,以企业的实践过程为任务流程,规划了数控加工与编程课程的教学体系,并构建了基于网络化教学平台的数字化教学资源库。     

COST INCREASES DUE TO DEMAND UNCERTAINTY IN MRP LOT SIZING

This paper analyzes the cost increases due to demand uncertainty in single-level MRP lot sizing on a rolling horizon. It is shown that forecast errors have a tremendous effect on the cost effectiveness of lot-sizing techniques even when these forecast errors are small. Moreover, the cost differences between different techniques become rather insignificant in the presence of forecast errors. Since most industrial firms face demand uncertainty to some extent, our findings may have important managerial implications. Various simulation experiments give insight into both the nature and the magnitude of the cost increases for different heuristics. Analytical results are developed for the constant-demand case with random noise and forecasting by exponential smoothing. It is also shown how optimal buffers can be obtained by use of a simple model. Although the analysis in this paper is restricted to simplified cases, the results merit further consideration and study. This paper is one of the first to inject forecast errors into MRP lot-sizing research. As such it attempts to deal with one of the major objections against the practical relevance of previous research in this area.     

A LOWER BOUND FOR THE SINGLE-LEVEL DYNAMIC HORIZON LOT-SIZING PROBLEM

Conventional production planning methods assume the existence of a medium- or longrange demand horizon. However, demand usually is known over a much shorter range; scheduling decisions must be made within this “decision window,” which rolls forward in time. This paper presents a new lower bound for lot-sizing heuristics in a rolling-horizon framework and compares it to the well-known Wagner-Whitin bound. The new bound indicates heuristic schedules that have costs close to the optimum. Rolling-horizon schedule costs are compared to corresponding static-horizon schedule costs (assuming the whole horizon is known in advance), using the ratio of decision-window size to the natural order cycle as a parameter. For values below unity, the rolling-horizon policy is significantly more costly. For values above one, the two policies have similar costs and actually converge as the parameter value increases.     

中日韩老年人互动方案研究

人口老龄化究竟是挑战还是机遇，关键在于如何充分利用老年人力资源，推动老有所为，实现积极老龄化。参与社会，扩大交流是中日韩三国老年人的共同要求。要充分认识到当前中日韩民间交流中的老年人的作用，切实推进老年人的文化交流与民间往来。中日韩三国积极老龄化的成功经验和有效做法具有相互学习和借鉴的价值，三国在应对人口老龄化领域有着广阔的合作空间和前景。中日韩三国应长期、积极地开展交流与合作。     

Social work values,anti-discriminatory practice and working with older lesbian service users

It has been suggested that social workers are not adequately meeting the needs of lesbians and gay men. This paper explores some of these concerns with reference to social work's theoretical underpinnings and value-base in relation to working with older, non-heterosexual women. The paper considers some of the particular issues that affect the lives and needs of older women whose primary relationships are or have been with other women. It concludes with a discussion of ways in which such issues may be addressed in social work education, training and practice.     

A modified hierarchical production planning system integrated with MRP: A case study

In this paper, a hierarchical planning system is proposed which integrates aggregate capacity planning with MRP. This system is to be implemented in a metal box manufacturing company which multi-user MRP system covering manufacturing activities as well as procurement sales order processing and accounting systems. The hierarchical planning system includes a medium-range aggregate planning model adapted to the firm's requirements and strategies. The model consists of a mathematical formulation which covers labour capacity has already installed a constraints and includes certain cost estimations in the objective function. The planning horizon of the medium range planning is taken as twelve months in order to cover sales seasonality. The aggregate production quantities resulting from the optimized medium-range planning model are disaggregated according to procedures already found in the literature. Furthermore, the theoretical infeasibilities pertaining to the disaggregation procedures are also resolved in an heuristic manner. Using the latter modified disaggregation procedure, a feasible disaggregated plan is generated for the whole planning horizon. The proposed plan is compared with the current production policy of the firm and it is observed that the proposed plan leads to backorder reduction.     

Methods used to teach social work students in the field: A research report from New Zealand

This article reports the findings of research conducted in three schools of social work in New Zealand on 'methods' used to teach social work students in the field. Students were polled before the first placement ( N = 80) to find how 'effective' they rated a range of teaching methods. This was followed up by a post-placement student survey ( N = 77) to ascertain the extent to which these same methods were employed by field educators. Pre- and post-placement student results were compared with the effectiveness ratings that field educators ( N = 130) gave to each method. Field educator and student pre-placement ratings listed most methods as being effective or very effective. Post-placement student survey results suggest consistent incongruity between the effectiveness ratings given to each 'method' by field educators, and the degree to which field educators actually utilised the methods with students during the field placement. Students report that methods enabling the direct observation of their practice were amongst those least used in the field.     

区域性学业水平测试质量分析——小学数学学业水平检测试卷与课程标准一致性的视角

区域性学业水平测试是地方教育行政部门监测教育质量的重要方法。因此,分析区域性学业水平测试质量就显得十分重要。为此,借鉴韦伯一致性分析模式,对某地区小学数学学业水平检测试卷的质量进行了尝试探究,即从学习领域和年级两个方面分析了区域性小学数学学业水平测试与课程标准的一致性水平状况及特征。同时,还从数与代数、空间与图形、统计与概率、实践与综合应用等学习领域和知识种类、知识深度、知识广度和知识分布平衡性等"一致性维度"进行了归因分析。