A conceptual development of Simons’ Levers of Control framework

The management control literature has been criticised for having concepts that are ill-defined. This causes mixed empirical results and makes it difficult to build a coherent body of knowledge. The paper addresses this issue by developing an important framework, that of Simons’ Levers of Control, which has been criticised in the past for its vague and ambiguous definitions. Using methods of concept analysis, the paper analyses prior literature to identify ambiguities with the different levers of control and uses examples from prior field studies to illustrate these ambiguities. The paper also analyses the positive and negative dimensions of controls, which, although part of Simons’ framework, have remained unexplored. For each ambiguity identified, the paper proposes a solution to improve concept definitions or to clarify the relationship between concepts. The result is a revised framework that explicitly separates managerial intentions for controls and employee perceptions of controls. Managerial intentions are comprised of three levels: 1) types of controls (social and technical) 2) which are organised as four control systems (strategic performance, operational performance, strategic boundaries and operational boundaries) and 3) which can be used diagnostically or interactively, have an enabling or constraining role and can lead to either reward or punishment. Finally, after defining the framework's concepts and explaining how they interact, the paper concludes by offering avenues for future research.     

Continuous‐time models,realized volatilities,and testable distributional implications for daily stock returns

We provide an empirical framework for assessing the distributional properties of daily speculative returns within the context of the continuous‐time jump diffusion models traditionally used in asset pricing finance. Our approach builds directly on recently developed realized variation measures and non‐parametric jump detection statistics constructed from high‐frequency intra‐day data. A sequence of simple‐to‐implement moment‐based tests involving various transformations of the daily returns speak directly to the importance of different distributional features, and may serve as useful diagnostic tools in the specification of empirically more realistic continuous‐time asset pricing models. On applying the tests to the 30 individual stocks in the Dow Jones Industrial Average index, we find that it is important to allow for both time‐varying diffusive volatility, jumps, and leverage effects to satisfactorily describe the daily stock price dynamics. Copyright © 2009 John Wiley & Sons, Ltd.     

A reduced form framework for modeling volatility of speculative prices based on realized variation measures

Building on realized variance and bipower variation measures constructed from high-frequency financial prices, we propose a simple reduced form framework for effectively incorporating intraday data into the modeling of daily return volatility. We decompose the total daily return variability into the continuous sample path variance, the variation arising from discontinuous jumps that occur during the trading day, as well as the overnight return variance. Our empirical results, based on long samples of high-frequency equity and bond futures returns, suggest that the dynamic dependencies in the daily continuous sample path variability are well described by an approximate long-memory HAR–GARCH model, while the overnight returns may be modeled by an augmented GARCH type structure. The dynamic dependencies in the non-parametrically identified significant jumps appear to be well described by the combination of an ACH model for the time-varying jump intensities coupled with a relatively simple log-linear structure for the jump sizes. Finally, we discuss how the resulting reduced form model structure for each of the three components may be used in the construction of out-of-sample forecasts for the total return volatility.     

利用生产停顿机会进行维修以提高产量

介绍Statoil公司提出的机会维修概念和它对生产所起的重要作用,举例说明机会维修的可行性,并对机会维修进行优化使它更好地为生产服务.     

A survey on pickup and delivery problems

This paper is the first part of a comprehensive survey on pickup and delivery problems. Basically, two problem classes can be distinguished. The first class, discussed in this paper, deals with the transportation of goods from the depot to linehaul customers and from backhaul customers to the depot. This class is denoted as Vehicle Routing Problems with Backhauls (VRPB). Four subtypes can be considered, namely the Vehicle Routing Problem with Clustered Backhauls (VRPCB – all linehauls before backhauls), the Vehicle Routing Problem with Mixed linehauls and Backhauls (VRPMB – any sequence of linehauls and backhauls permitted), the Vehicle Routing Problem with Divisible Delivery and Pickup (VRPDDP – customers demanding delivery and pickup service can be visited twice), and the Vehicle Routing Problem with Simultaneous Delivery and Pickup (VRPSDP – customers demanding both services have to be visited exactly once). The second class, dealt with in the second part of this survey, refers to all those problems where goods are transported between pickup and delivery locations. These are the Pickup and Delivery Vehicle Routing Problem (PDVRP – unpaired pickup and delivery points), the classical Pickup and Delivery Problem (PDP – paired pickup and delivery points), and the Dial-A-Ride Problem (DARP – passenger transportation between paired pickup and delivery points and user inconvenience taken into consideration). Single as well as multi vehicle versions of the mathematical problem formulations are given for all four VRPB types, the corresponding exact, heuristic, and metaheuristic solution methods are discussed.