Algorithm portfolios for logistics optimization considering stochastic demands and mobility allowance

The vehicle routing problem with stochastic demand (VRPSD) is a well known NP-hard problem. The uncharacteristic behaviour associated with the problem enhances the computational efforts required to obtain a feasible and near-optimal solution. This paper proposes an algorithm portfolio methodology based on evolutionary algorithms, which takes into account the stochastic nature of customer demand to solve this computationally complex problem. These problems are well known to have computationally complex objective functions, which make their solutions hard to find, particularly when problem instances of large dimensions are considered. Of particular importance in such situations is the timeliness of the solution. For example, Apple was forced to delay their shipments of iPads internationally due to unprecedented demand and issues with their delivery systems in Samsung Electronics and Seiko Epson. Such examples illustrate the importance of stochastic customer demands and the timing of delivery. Moreover, most of the evolutionary algorithms, known for providing computationally efficient solutions, are unable to always provide optimal or near optimal solutions to all the VRPSD instances within allocated time interval. This is due to the characteristic variations in the computational time taken by evolutionary algorithms for same or varying size of the VRPSD instances. Therefore, this paper presents portfolios of different evolutionary algorithms to reduce the computational time taken to resolve the VRPSD. Moreover, an innovative concept of the mobility allowance (MA) in landmoves based on the levy’s distribution function has been introduced to cope with real situations existing in vehicle routing problems. The proposed portfolio approach has been evaluated for the varying instances of the VRPSD. Four of the existing metaheuristics including Genetic Algorithm (GA), Simulated Annealing (SA), Artificial Immune System (AIS), TABU Search (TS) along with new neighbourhood search, are incorporated in the portfolios. Experiments have been performed on varying dimensions of the VRPSD instances to validate the different properties of the algorithm portfolio. An illustrative example is presented to show that the set of metaheuristics allocated to certain number of processors (i.e. algorithm portfolio) performed better than their individual metaheuristics.     

Risk management, project success, and technological uncertainty

In times of increased competition and globalization, project success becomes even more critical to business performance, and yet many projects still suffer delays, overruns, and even failure. Ironically, however, risk management tools and techniques, which have been developed to improve project success, are used too little, and many still wonder how helpful they are. In this paper we present the results of an empirical study devoted to this question. Based on data collected on over 100 projects performed in Israel in a variety of industries, we examine the extent of usage of some risk management practices, such as risk identification, probabilistic risk analysis, planning for uncertainty and trade-off analysis, the difference in application across different types of projects, and their impact on various project success dimensions. Our findings suggest that risk management practices are still not widely used. Only a limited number of projects in our study have used any kind of risk management practices and many have only used some, but not all the available tools. When used, risk management practices seem to be working, and appear to be related to project success. We also found that risk management practices were more applicable to higher risk projects. The impact of risk management is mainly on better meeting time and budget goals and less on product performance and specification. In this case, we also found some differences according levels of technological uncertainty. Our conclusion is that risk management is still at its infancy and that at this time, more awareness to the application, training, tool development, and research on risk management is needed.     

Dimensions of uncertainty and their moderating effect on new product development project performance

In this study, we measure the dimensions of uncertainty, starting from the definitions constructed for and generally used in innovation projects. We then evaluate their direct and indirect effects on the performance of product and service development projects. Four dimensions of uncertainty are delimited with satisfactory validity and reliability, suggesting a differential moderating effect of the four types of uncertainty (technical and project uncertainty, market uncertainty, fuzziness and complexity) depending on the performance dimension (effectiveness and efficiency) and co‐moderator (project methods and human resource adequacy). Of the four dimensions explored, technical and project, and market uncertainty are true moderators and have the largest interactive effect, fuzziness has a strong direct effect on both performance dimensions whereas complexity weakly directly influences effectiveness. The latter two also influence the relations between performance and the factors related to human resources and project management methods.     

The courage to choose! Primogeniture and leadership succession in family firms

Research Summary : Building on a unique data set with information on the nuclear structure of entrepreneurial families, we integrate leadership succession into a socioemotional wealth (SEW) logic to test the antecedents and consequences of primogeniture vis‐à‐vis second‐ or subsequent‐born selection in family firm succession. Our findings suggest that appointing a family firstborn sibling is more likely when there is a high degree of SEW endowment and the family firm has pre‐succession performance below aspiration levels. Next, we find that appointing a second‐ or subsequent‐born sibling has a positive and significant effect on post‐succession firm profitability, particularly when the firm is in its second generation or later. Managerial Summary : What drives succession choices in family firms? What are the performance implications of each succession choice? These are questions of vital relevance for every business owner. Focusing on the pool of potential family heirs at the time of succession, our study adds to the debate on the drivers of succession choices by suggesting that having a family intensive governance structure fosters primogeniture as the main succession logic, even when the family firm is experiencing lower profitability. Our study informs business owners on the implications of different succession policies, suggesting that family firms that have the courage to disregard primogeniture and choose more wisely the family successor are also the ones experiencing higher post‐succession performance.     

Cash flow at risk valuation of mining project using Monte Carlo simulations with stochastic processes calibrated on historical data

Mining projects are subject to multiple sources of market uncertainties such as metal price, exchange rates, and their volatilities. Assessing a mining project's exposure to market risk usually requires Monte Carlo simulations to capture a range of probable outcomes. The probability of a major loss is extracted from the probability density function of simulated prices at a given time into the future. This article proposes an approach to calibrate the stochastic process to be used in Monte Carlo simulations. The simulations are then used for measuring the cash flow at risk of a mining project. To assess the performance of the proposed approach, a case study is conducted on a mining project. The results show that the calibration approach is robust and apt at fitting various stochastic processes to historical observations.     

The role of functional and demographic diversity on new product creativity and the moderating impact of project uncertainty

Earlier studies have shown inconsistency in the impact of team diversity on the effective functioning of New Product Development (NPD) teams. This inconsistency has been attributed to the insufficient amount of research on a possible complex (non-monotonic) relationship between team diversity and team performance and the possible boundary conditions of this relationship. Addressing numerous calls for future studies on these issues, we examined whether an inverted-U relationship exists between team diversity (i.e., functional and demographic) and its outcomes (i.e., new product creativity), using project uncertainty as a key moderator. The results of an empirical study with a sample of 103 new product development teams showed an inverted U-shaped functional diversity–new product creativity relationship. Moreover, the results showed that the direct relationship between functional diversity and new product creativity was stronger when project uncertainty was high as opposed to when it was low. On the other hand, the direct relationship between demographic diversity and new product creativity was weaker when project uncertainty was high as opposed to when it was low.     

Market uncertainty and the monopolist incentive to innovate

A monopolist who undertakes R&D projects and faces demand uncertainty in the product market may either underproduce output and overinvest in R&D or underproduce and underinvest in R&D in comparison with the deterministic case. The actual outcome depends on the nature of process innovation and on the monopolist's attitude toward risk.     

Estimating store choices with endogenous shopping bundles and price uncertainty

We develop a structural model of retail store choices for which household shopping plans and price beliefs are endogenously determined. In our model individual households make their store choices based on their expected basket costs, which are determined by their shopping plans and price beliefs. Previous studies use realized purchases as a proxy for unobserved shopping lists and also assume homogenous price expectation across all households over the entire sample period. Our approach improves the measures of expected basket costs by estimating intended shopping lists of households using a duration model and also by constructing household-, time-, store-, and goods-specific price expectations. In our empirical application using a scanner data set, we find that the store choices become significantly more elastic to prices when the correction is applied.     

Managing inventory with two suppliers under yield uncertainty and risk aversion

In this paper, we consider a single-product single-period inventory model in which the retailer can source from two suppliers. The primary supplier is cheaper but unreliable in the sense that it generates supply yield uncertainty, whereas the secondary supplier is perfectly reliable but more expensive. The reliable supplier's capacity is fixed and the retailer cannot order more than the quantity reserved in advance. We study the problem in the context of a risk-averse retailer who has to determine the optimal order quantity from the primary supplier and the optimal reserved quantity from the secondary supplier. We develop the model in the perspective of a low risk averse retailer and quantify the risk via an exponential utility function. We show by numerical experiments how the resulting dual sourcing strategies differ from those obtained in the risk-neutral analysis. We also examine the sensitivity of some model-parameters on the optimal decisions.     

A relationship strategy perspective on relationship portfolios: Linking customer profitability,commitment, and growth potential to relationship strategy

The paper develops a three-dimensional portfolio model for business relationships which distinguishes among six different categories. Based on assessments of customer profitability, customer commitment, and growth potential, the positioning of a given customer relationship in the portfolio allows managers to determine appropriate customer relationship strategies and appropriate performance indicators. Results from applying the portfolio model are reported and managerial implications and future research are discussed.     

Relevance of organizational capabilities and its dynamics: what to learn from entrants' product portfolios about the determinants of entry timing

The resource‐based view of the firm suggests that the timing of market entry by a firm depends on its resources and capabilities, but several important questions remain. First, in a high‐velocity market where capabilities change quickly, how does entry timing depend on the capabilities at varying points in time? Second, how much flexibility does a firm have in altering its capabilities to achieve desirable entry timing? To answer these questions, this study sets out to develop a dynamic, refined version of the resource‐based view that parameterizes a firm by its time‐varying capability relevance with respect to a focal market, and makes predictions on entry timing and future growth of capability relevance. The study develops a novel approach that uses the entrants' product portfolios to infer a potential entrant's capability relevance. The results based on a panel of potential entrants show that the initial and current capability relevance each affect entry timing alone, revealing the persistent effect of the initial condition. However, given the knowledge of the current capability relevance, the initial relevance has no effect on entry timing, suggesting that the initial relevance affects entry timing through its influence on the current relevance. Firms that are in an initially unfavorable position can still achieve early entry, provided that they improve their capability relevance over time. Copyright © 2008 John Wiley & Sons, Ltd.     

Using R&D portfolio management to deal with dynamic risk

We develop a theoretical framework for understanding why firms adopt specific approaches for the management of innovation project portfolios. Our theory focuses on a key contingency factor for innovation, namely the dynamics of competitive environments. We use four dimensions to characterize the patterns of environmental dynamics: velocity, turbulence, growth and instability. The paper then proposes the concept of dynamic risk as a determinant of portfolio management processes. Dynamic risk results from second‐order learning by a firm confronted with a specific dynamic pattern in its environment. This learning concerns the likely nature of threats and the required updating of cognitive frameworks in such environments. Attempts to deal with dynamic risk enable various actors inside the firm to understand what kind of dynamic capabilities are needed in their innovation portfolio management processes. As a result of this diffuse learning, firms tend to favor certain common characteristics in their concrete portfolio management activities. To advance the theorizing of these characteristics, the paper also proposes four dimensions of portfolio management: structure, commitment, emergence and integration. Based on arguments inspired by the dynamic capability and related literatures, we advance a series of hypotheses, that relate environmental dynamics dimensions and portfolio management dimensions. These hypotheses are tested based on a survey of 795 firms in a variety of sectors and on four continents, using original scales and structural equation modeling methods. The results show, among other findings, that high‐velocity environments favor structured as well as integrated portfolio management approaches, while high‐growth environments favor approaches that are structured but commit significant resources to each project as well. Turbulent environments favor approaches that are emergent, but also, contrary to our expectations, have high resource commitment levels. Finally, firms in unstable environments have a marginal preference for emergent approaches. Results could help advance the dynamic contingency theoretical perspective on dynamic capabilities, as well as improve the practice of innovation portfolio management.     

Business model innovation and decision making: uncovering mechanisms for coping with uncertainty

As a research subject, business model innovation spans the strategy, innovation, and entrepreneurship fields. Yet, despite the importance of the concept, prior work has paid little attention to how decision-makers cope with uncertainty and gain understanding about interdependencies in new business model configurations. To address this gap, we combine top-down theorising and evidence-based exploration and seek to unpack some of the coping mechanisms that operate in the evolutionary view of business model innovation. Using in-depth interviewing to collect data, our study reveals five strategies – customer centricity, value co-creation, capability evolution, ecosystem growth, and adaptive pricing – that decision-makers apply to cope with uncertainty in business model innovation. We find that coping mechanisms support decision making during the development of new business models. Furthermore, we find that the five coping strategies delineate decision making for value proposition, value creation, and value capture configurations in more detail than existing literature has described. Our findings have important implications for decision making in business model innovation.     

Centralized and decentralized control polices for a two-stage stochastic supply chain with subcontracting

An analysis of control policies for a two-stage supply chain with subcontractors at each stage is presented when decisions at each stage concerning safety stocks, backorders, and subcontracting are made jointly or in a decentralized manner. The inventory/admission control policies considered are base stock, echelon base stock and partial backordering, and the objective is to maximize the mean profit rate of the system. The optimal control parameters are found by exhaustive search using Markov chains. From numerical examples it appears that the policies which manage jointly sales and production levels in each stage provide much higher overall (system) profits than decentralized policies, although the latter are individually more profitable for the second stage. In addition, partial backordering provides the system with an extra profit above those that result from the lost sales (no backordering) and complete backordering policies. Finally, a number of numerical results show the impact of variations in certain system parameters on the optimal control parameters and the corresponding profit.     

An application-oriented guide to R&D project selection and evaluation methods

The purpose of this paper is to provide managers with a set of guidelines to help them to choose the project evaluation and selection model that best suits their business environments. To this end the authors have surveyed the literature of the subject and used contacts made in training workshops with Swiss industry.
From this information the authors have identified five key issues — signposts that mark the route towards the appropriate project selection method. Once a sufficiency of project proposals has been identified — more than could be implemented with the resources available — then one takes into account successively how far the selection parameters can be quantified, how far one project interferes with or depends on the completion of another, whether a project has one or more than one objective, and the degree of acceptable risk. The procedure is presented in the form of a binary decision tree the various branches of which lead ultimately to twelve archetypal groups of methods. Each group is in principle suited to a practical situation represented by some combination of the key issues recognizable by a manager.
The paper discusses the strengths, weaknesses, limitations and practicality of the methods falling into each group. It concludes with suggestions about how a framework could be extended and refined. Keywords: Research and Development, Project Selection.     

由现场签证引发的合同外工程的处理与计量

本文结合现场签证的案例论述了合同工程量清单外新增工程量的处理方法和注意事宜,以及工程变更与计日工的区分。     

Motivation levels in pupils project work: observations from an action research programme with particular reference to groupwork

Conclusions The new Proposals for Technology for England and Wales (DFE December 1992) suggest Design and Make Tasks (DMTs) ie. project work as being the major method of Design and Technology learning. This article has been primarily concerned with questions of motivation within project work but has touched on other-fundamental aspects. As a teaching/learning technique group project work has limitations as indicated above. However it would appear that many teachers do not recognise these limitations and produce poor practice. An example would be the frequent failure to use end of lesson debriefs to share individual's experience and to reflect. It is important that we now begin to develop a clearer understanding of project work as a learning experience. The DFE document offers little guidance; more research and debate is necessary to identify the assumptions and put forward practical advice on how to maximise the potential benefits of project work in Design and Technology.     

Considering stochastic lead times in a manufacturing/remanufacturing system with deterministic demands and returns

In this paper we study a manufacturing/remanufacturing system with stochastic lead times and a constant demand. We base our approach on previous research in which we have developed models to describe an inventory system with stochastic lead times. In this paper, we first adopt this method to manufacturing/remanufacturing situations, where there are essentially two supply sources for replenishing serviceable inventory. We then provide a solution procedure when a cycle ordering policy is used. Secondly, we investigate the possibility to use a dual sourcing ordering policy in which each order is split between a manufacturing and a remanufacturing process. Finally, we compare the two ordering policies and illustrate how the lead-time patterns influence the economic consequences.     

LNG项目模块化应用实践及对中国模块厂的挑战

模块化已成为一些陆上LNG项目和海上浮式液化天然气(FLNG)项目建设的重要实施方式.从模块化技术特点出发,介绍陆上LNG和海上FLNG模块化技术应用的进展,分析中国模块化厂的现状和所面临的挑战,建议:1)促进中国相关工程公司与国际工程公司开展国际项目合作;2)加强创新技术研发和关键设备研发;3)培养中方模块化工程技术管理人才;4)积极参与海外中型项目模块化建造,为进一步参与大型天然气区块开发积累工程经验.