SHIFTING PRODUCTION BOTTLENECKS: CAUSES,CURES, AND CONUNDRUMS

We examine the phenomenon of shifting production bottlenecks from an analytic perspective. We quantify the propensity of a work center to be a bottleneck, defined as maximal queue length, using a simple Jackson production network model. Comparison of the analytic model against an empirical simulation-based model shows that the two are in good agreement. A scalar measure of bottleneck shiftiness is proposed and used to investigate several policies for mitigating shiftiness. Simulation experiments show that several commonly observed managerial policies for coping with shifting bottlenecks actually increase shiftiness, but that shiftiness declines when the capacity of nonbottleneck resources is increased.     

An investigation of output flow control,bottleneck flow control and dynamic flow control mechanisms in various simple lines scenarios

Flow control mechanisms have been a topic of academic research for several years. With the growth of business-wide information systems such as enterprise resource planning and supply chain, better planning, scheduling and control of the business transformation process is required in order to achieve increased throughput, reduced inventories, shorter lead times and reduced tardiness. This research compares two new approaches to flow control, output flow control and bottleneck flow control to a real-time flow control system, dynamic flow control. Both output and bottleneck flow control mechanisms are much simpler to implement and manage than dynamic flow control in that they do not require continual feedback and rescheduling. Line characteristics, such as location of breakdowns with respect to the bottleneck, the location of the bottleneck when breakdowns occur, and the impact of variability of processing times on the performance measures (output, WIP level, lateness, and number of tardy jobs) for these three flow control mechanisms are compared. Both output and bottleneck flow control mechanisms perform favourably (particularly bottleneck) under different scenarios and warrant further study across a wider range of scenarios (mixed models, job shops, etc.).     

The impact of non-bottleneck variation in a manufacturing cell

Protective capacity is the 'extra' capacity placed at non-bottleneck resources to absorb random disruptions in planned levels of performance so that the bottleneck resource continues to be effectively utilized. A full factorial experiment with a simulation model was conducted to explore issues associated with the quantity and location of processing variance in a five-station manufacturing cell. The cell's performance was measured using both mean flow time ( MFT ) and bottleneck shiftiness ( SHIFT ) for 3 patterns of variance for the non-bottlenecks at 5 different levels of variation. In order to investigate the importance of the quantity of added capacity on the variation both a low level of protective capacity (10%) and a high level (50%) were considered. The results indicate that having the higher variation work centres close to the bottleneck provides reduced MFT and SHIFT . The performance measures improved at both the low and high setting of protective capacity.     

A TUTORIAL ON BOTTLENECK DYNAMICS: A HEURISTIC SCHEDULING METHODOLOGY

We give a tutorial on bottleneck dynamics. Bottleneck dynamics is a scheduling framework that uses approximate dual resource prices to make decentralized decisions. The basic idea is to establish a price for a resource as a function of the set of jobs that need to be processed by the resource. Tasks are then sequenced according to a cost/benefit ratio. Starting with one resource sequencing problems, we describe how priorities for jobs can be developed and how they translate into resource prices. We then describe how resource prices can be approximated in a multiresource situation and how lead times which are critical for these approximations can be accurately computed. We also describe a number of studies that have shown bottleneck dynamics to be an effective approach in several different problem areas.     

Online bottleneck matching

We consider the online bottleneck matching problem, where $k$ server-vertices lie in a metric space and $k$ request-vertices that arrive over time each must immediately be permanently assigned to a server-vertex. The goal is to minimize the maximum distance between any request and its server. Because no algorithm can have a competitive ratio better than $O(k)$ for this problem, we use resource augmentation analysis to examine the performance of three algorithms: the naive Greedy algorithm, Permutation, and Balance. We show that while the competitive ratio of Greedy improves from exponential (when each server-vertex has one server) to linear (when each server-vertex has two servers), the competitive ratio of Permutation remains linear when an extra server is introduced at each server-vertex. The competitive ratio of Balance is also linear with an extra server at each server-vertex, even though it has been shown that an extra server makes it constant-competitive for the min-weight matching problem.     

Polynomially solvable special cases of the quadratic bottleneck assignment problem

Quadratic bottleneck assignment problems (QBAP) are obtained by replacing the addition of cost terms in the objective function of a quadratic (sum) assignment problem by taking their maximum. Since the QBAP is an NP\mathcal{NP}-hard problem, polynimially solvable special cases of the QBAP are of interest. In this paper we specify conditions on the cost matrices of QBAP leading to special cases which can be solved to optimality in polynomial time. In particular, the following three cases are discussed: (i) any permutation is optimal (constant QBAP), (ii) a certain specified permutation is optimal (constant permutation QBAP) and (iii) the solution can be found algorithmically by a polynomial algorithm. Moreover, the max-cone of bottleneck Monge matrices is investigated, its generating matrices are identified and it is used as a tool in proving polynomiality results.     

The Financial Impact of FSC Certification in the United States: A Contingency Perspective

This article focuses on an important and emergent standard for sustainable operations management: the Forest Stewardship Council (FSC) certification. Unlike similar certifications, its focus is on the entire upstream supply chain, reflecting the criticality of supply chain management to ensure sustainable products. We investigate the financial impact from FSC certification, offering valuable decision support for managers considering this certification. Taking a contingency perspective, we view a firm's supply chain position and its prior certification to the ISO 14001 standard as influencing the results. Drawing on signaling theory, we suggest that firms farther downstream in the supply chain realize significantly greater abnormal financial performance benefits than firms upstream in the supply chain. We further hypothesize that firms that were not ISO 14001 certified at the time of FSC certification realize significantly greater abnormal financial performance benefits than firms that did have the ISO 14001 certification. To test these hypotheses, we utilize financial data of all publicly traded firms in the United States that have obtained the FSC certification, and assess whether FSC certification leads to abnormal performance benefits considering the above contingencies. Data collected from the FSC Certificate Database and Compustat, employed in an event study, provide support for our hypotheses. Overall, our findings contribute to research on decision making in the context of sustainable operations management, and offer a plausible explanation for contradictory results in prior studies. We highlight the applicability of signaling theory to decision sciences research, and stress the need to consider contingencies in sustainability management research.     

Serve or skip: the power of rejection in online bottleneck matching

We consider the online matching problem, where n server-vertices lie in a metric space and n request-vertices that arrive over time each must immediately be permanently assigned to a server-vertex. We focus on the egalitarian bottleneck objective, where the goal is to minimize the maximum distance between any request and its server. It has been shown that while there are effective algorithms for the utilitarian objective (minimizing total cost) in the resource augmentation setting where the offline adversary has half the resources, these are not effective for the egalitarian objective. Thus, we propose a new Serve-or-Skip (SoS) bicriteria analysis model, where the online algorithm may reject or skip up to a specified number of requests, and propose two greedy algorithms: GriNN(t) and \({{\textsc {Grin}}^*(t)}\). We show that the SoS model of resource augmentation analysis can essentially simulate the doubled-server-capacity model, and then examine the performance of GriNN(t) and \({\textsc {Grin}^*(t)}\).     

社会资本和公司企业家精神与绩效的关系:组织学习的中介作用——江苏与广东新兴企业的实证研究

近年来,社会资本和企业家精神被认为是新兴企业取得竞争优势的关键因素。虽然很多学者认为组织学习在社会资本和公司企业家精神与组织绩效之间起了中介作用,但了解“如何发生作用”的知识要远远难于“是什么”,并且极少有研究给出实证结果。在转型经济中类似的研究更是缺乏。本文以中国江苏和广东两省的676家新兴企业为被试对象,对社会资本和公司企业家精神是否以及如何通过组织学习影响组织的绩效进行实证研究。结果表明组织学习在社会资本和公司企业家精神—组织学习—组织绩效链中起到了至关重要的作用,是通过社会资本和公司企业家精神提升组织绩效的瓶颈。     

Does strategic corporate performance depend on corporate financial architecture? Empirical study of European,Russian and other emerging market’s firms

Performance of the firm depends on its structural dimensions: capital structure, ownership structure and corporate governance. Their interactions are known as corporate financial architecture according to S. Myers. In this paper we analyze financial architecture which is a mix of ownership structure, capital structure, control and board’s composition, and therefore, provides the given framework for improving corporate performance. We contribute to the literature by different attributes of our study. In contrast to most empirical papers on performance, we develop integrated rather than segmented approach combining the intrinsic components of corporate financial design in one research model. We introduce new variable to capture the structure of ownership for the purpose of performance analysis. Our third contribution is based on comparative analysis of the influence of financial architecture over corporate performance in rather different capital market environment: developed European and emerging (developing) capital market’s countries. We start with a classic empirical model of the impact of ownership structure, capital structure and other components of financial architecture on the corporate performance. Further we verify the validity of exogenous nature of key variables of the classic model when applying it to companies in developed and emerging market environment. Our results could have some important policy implications for the firms in normal economic environment as well as in the period of global economic crisis. We found that the higher proportion of related ownership which indicates investors with significant voting power and the board’s composition affect firm performance positively. The related shareholders and independent directors seem to add more value to firms while the impact of government ownership differs depending on the country. The emerging market’s sample versus the one from developed countries proves the stronger influence of corporate financial architecture over performance.     

不同阶段研发投资对企业绩效的动态效应研究:基于中国上市公司的面板数据分析

研发投资是提高企业绩效的重要途径,不同阶段的的研发投资对于企业绩效的改善存在着差异化作用。本文构建了不同阶段研发投资对企业绩效影响效应的理论模型,并以我国103家上市公司2010-2016年的相关数据为样本,从动态效应的实证分析阶段和开发阶段两个阶段的投资强度对企业绩效影响的异同,结果发现:研究阶段和开发阶段的投资对企业绩效影响均具有正向的积极影响作用,开发阶段的投资在当期对企业绩效的影响较强但不可持续,研究阶段的投资具有滞后效应并且对企业绩效的提升有比较长远的影响。因此过多关注开发阶段的投资并不能有效提高企业绩效,企业应加大研究阶段的投资,以更好地实现其在提高企业绩效中的长效作用。     

The dynamics of customer dissatisfaction in supply chains

This paper describes field research and its findings that investigate the relationship of a firm's position in the supply chain to behaviour. Specifically, perceptions of requirements, performance and customer satisfaction/dissatisfaction are the behavioural issues of interest here. The field research was carried out in four European supply chains in the automotive aftermarket, or spares industry. It was proven statistically and qualitatively that, in the chains studied, upstream relationships contained more customer dissatisfaction and more misperceptions about performance than did downstream relationships. Delivery performance was identified as the major cause of these problems, This has implications for planning and control. First, the Forrester-type swings in information upstream, proven in industrial dynamics, make planning and control decisions more difficult; this research identifies the detrimental effect of this on customer satisfaction. Secondly, measurement of delivery performance is identified as being a critical issue; not only should measures be made in planning and control but also they should be communicated and agreed with customers to prevent misperceptions occurring. As this research showed these misperceptions to be positively correlated to customer dissatisfaction, efTort to remove them from relationships should be treated as a priority.     

Critical objective function values in linear sum assignment problems

The linear sum assignment problem has been well studied in combinatorial optimization. Because of the integrality property, it is a linear programming problem with a variety of efficient algorithms to solve it. In the given research, we present a reformulation of the linear sum assignment problem and a Lagrangian relaxation algorithm for its reformulation. An important characteristic of the new Lagrangian relaxation method is that the optimal Lagrangian multiplier yields a critical bottleneck value. Lagrangian relaxation has only one Lagrangian multiplier, which can only take on a limited number of values, making the search for the optimal multiplier easy. The interpretation of the optimal Lagrangian parameter is that its value is equal to the price that must be paid for all objects in the problem to be assigned.     

基于活动方法的瓶颈模型与拥挤收费问题研究

Vickrey提出的基于出行的瓶颈模型以出行作为分析单位,没有考虑出行与活动之间的相互关联.本文对Vickrey的瓶颈模型进行了拓展,提出了基于活动的瓶颈模型来研究通勤者早晨上班出发时间决策问题,模型考虑了通勤者对出行负效用与活动效用之间的权衡.在基于活动的瓶颈模型的基础上,分别研究了常数和线性边际活动效用下瓶颈动态拥挤收费和阶梯收费问题,并与传统的瓶颈模型的解进行比较.结果表明,当活动的边际效用为线性函数时,瓶颈处最优动态收费曲线不再呈分段线性关系,而是分段二次曲线;与基于活动的瓶颈模型相比,传统的基于出行的瓶颈模型将高估瓶颈处的排队延误、阶梯收费水平,以及早高峰的开始和结束时间;基于出行的瓶颈模型和常数边际活动效用下的瓶颈模型导致的最优阶梯收费是最优动态收费最大值的一半,并且刚好消除瓶颈处排队延误的一半;与线性边际活动效用下的瓶颈模型相比较,两者低估了阶梯收费能消除的瓶颈排队,从而低估了阶梯收费的效率.     

CEO proactiveness,innovation, and firm performance

Chief Executive Officers (CEOs) are essential in driving firm innovation. However, despite existing research on CEO personality characteristics and firm innovation and performance, we know relatively little about how personality characteristics reflecting anticipatory action and strong outcome-oriented components, such as proactiveness, shape firm innovation and performance. We explore the relationship between CEO proactiveness and three facets of organizational innovation, as well as its impact on firm performance. We suggest that CEO proactiveness is manifested in different network-building, problem-solving, and feedback-seeking behaviors with different implications for exploratory innovation, exploitative innovation, and organizational ambidexterity, and that its effect on firm performance is partially mediated by organizational ambidexterity. By examining the influence of this important CEO personality characteristic on key firm strategic choices and performance, we extend research on strategic leadership and firm innovation and performance.     

Teamworking and organizational performance: A review of survey‐based research

This paper presents a review of recent survey‐based research looking at the contribution of teamwork to organizational performance. In particular, it focuses on empirical studies in which both teamwork and performance are directly measured in a quantitative way. The paper begins by identifying four interrelated dimensions of teamwork effectiveness: attitudinal, behavioural, operational and financial. The first two represent transmission mechanisms by which organizational performance can be improved. The latter two provide direct measures of organizational outcomes. The review shows that teamworking has a positive impact on all four dimensions of performance. It also reveals that, when teamwork is combined with structural change, performance can be further enhanced. The paper concludes by highlighting some important research gaps that future studies could address.     

A comparison of fixed and dynamic pricing policies in revenue management

We consider the problem of selling a fixed capacity or inventory of items over a finite selling period. Earlier research has shown that using a properly set fixed price during the selling period is asymptotically optimal as the demand potential and capacity grow large and that dynamic pricing has only a secondary effect on revenues. However, additional revenue improvements through dynamic pricing can be important in practice and need to be further explored. We suggest two simple dynamic heuristics that continuously update prices based on remaining inventory and time in the selling period. The first heuristic is based on approximating the optimal expected revenue function and the second heuristic is based on the solution of the deterministic version of the problem. We show through a numerical study that the revenue impact of using these dynamic pricing heuristics rather than fixed pricing may be substantial. In particular, the first heuristic has a consistent and remarkable performance leading to at most 0.2% gap compared to optimal dynamic pricing. We also show that the benefits of these dynamic pricing heuristics persist under a periodic setting. This is especially true for the first heuristic for which the performance is monotone in the frequency of price changes. We conclude that dynamic pricing should be considered as a more favorable option in practice.     

Competitive intelligence embeddedness: Drivers and performance consequences

The proliferation of Web-based information sources and social media draw firms' attention to these channels as sources of competitive intelligence (CI). To date, research has focused mainly on information collection techniques rather than on CI uses and its influence on firm performance. We define CI embeddedness as the extent to which management and employees incorporate CI in daily routines, so that actionable knowledge is transferred throughout the organization. A survey of 124 decision makers reveals positive impact of Web CI sources as well as alliances with information providers on CI embeddedness. Furthermore, while CI embeddedness shows no direct influence on firms’ performance, it has a mediated effect on performance through customer satisfaction.     

International Strategy and Knowledge Creation: The Advantage of Foreignness and Liability of Concentration

International business scholars increasingly emphasize regional strategies based on an optimal location of downstream sales. There has been less scholarly attention, however, to the relationship between international strategy and upstream knowledge creation including R&D. Building on contemporary strategic management theory and the knowledge‐based view we remedy this. The viability of home‐regional or bi‐regional strategies is based on common assumptions that imply negative consequences of distance and foreignness for downstream sales and marketing and benefits from agglomeration for upstream knowledge creation activities including R&D. In contrast, we propose that upstream knowledge creation, radical innovation in particular, rather gains from distance and foreignness and from being dispersed, suggesting the effectiveness of a global strategy. Based on the resource‐based view and recent research on the economics of strategic opportunities and competitive advantage, we provide theoretical explanations for this. We demonstrate how a global multinational corporation is uniquely equipped with knowledge extensity including heterogeneous social‐identity frames in multiple sub‐units. Thanks to arbitrage advantages between the sub‐units’ separate and often locally embedded knowledge, a global multinational corporation can address complex interdependences and interactions between knowledge sets required for knowledge creation. This suggests that maximum exploration capabilities are made possible by a global rather than a home‐regional or bi‐regional strategy.     

The effectiveness of input control based on aggregate versus bottleneck work loads

This study compares input control based on aggregate shop loads with that based on bottleneck resource loads. Two appropriate release mechanisms are developed and compared in flow and job shops that have various levels of a bottleneck constraint. Simulation results show that both the level of bottleneck and the flow pattern influence the effectiveness of the strategies. Release based on aggregate loads works well when shop loads are balanced or when there is a bottleneck but the flow is highly structured, as in a flow shop. Release based on bottleneck loads works best when flow patterns are less structured, as in a job shop.