Using system dynamics in a discrete-event simulation study of a manufacturing plant

Purpose - To provide an example of the use of system dynamics within the context of a discrete-event simulation study. Design/methodology/approach - A discrete-event simulation study of a production-planning facility in a gas cylinder-manufacturing plant is presented. The case study evidence incorporates questionnaire responses from sales managers involved in the order-scheduling process. Findings - As the project progressed it became clear that, although the discrete-event simulation would meet the objectives of the study in a technical sense, the organizational problem of "delivery performance" would not be solved by the discrete-event simulation study alone. The case shows how the qualitative outcomes of the discrete-event simulation study led to an analysis using the system dynamics technique. The system dynamics technique was able to model the decision-makers in the sales and production process and provide a deeper understanding of the performance of the system. Research limitations/implications - The case study describes a traditional discrete-event simulation study which incorporated an unplanned investigation using system dynamics. Further, case studies using a planned approach to showing consideration of organizational issues in discrete-event simulation studies are required. Then the role of both qualitative data in a discrete-event simulation study and the use of supplementary tools which incorporate organizational aspects may help generate a methodology for discrete-event simulation that incorporates human aspects and so improve its relevance for decision making. Practical implications - It is argued that system dynamics can provide a useful addition to the toolkit of the discrete-event simulation practitioner in helping them incorporate a human aspect in their analysis. Originality/value - Helps decision makers gain a broader perspective on the tools available to them by showing the use of system dynamics to supplement the use of discrete-event simulation. © Emerald Group Publishing Limited.

The impact of the performance measurement systems in setting the 'direction' in the University of Warwick

This paper presents a case study examining the role of performance measurement systems in setting organizational ‘direction’. There is a growing concern in the existing literature to link the development of organizational ‘direction’ with performance measurement systems. Furthermore, the alignment between organizational ‘direction’, strategy and performance measurement is an area of increasing interest for both academics and practitioners. However, there is no adequate research recorded in the literature on the use of the performance measurement systems and the potential impact that performance measurement can have in setting the organizational ‘direction’. This study reports the findings of a case study from one of the leading academic institutions in the UK, the University of Warwick, presenting the main characteristics of its performance measurement system and attempting to explain the connection with setting the university’s ‘direction’.

Functional near vision assessment in presbyopia

The aim of this thesis was to develop standards of best practice for the subjective assessment of near visual function in presbyopia. Near visual acuity (VA) is a quick and simple measure but an assessment of the maximum reading speed and the smallest print size that can maintain this are equally important, to gain a better reflection of real world visual function. These metrics are dependent on the amplitude of accommodation (AoA) and often this must be evaluated using subjective techniques. Defocus curves are less susceptible than the push-up/push-down test to the influence of blur tolerance but their implementation must be standardised such that letter sequences and the order of lens presentation are randomised, to avoid memory effects, whilst the AoA should be quantified as the range of defocus for which only the best VA is maintained. In addition to such clinical assessments, subjective questionnaire evaluations are also important, to determine whether at least an individual’s needs are met. The Near Activity Visual Questionnaire (NAVQ) developed in this thesis can be used for this. Using these standardised near vision metrics it is shown that visual performance with monovision and multifocal contact lenses is comparable whilst initial outcomes of single optic ‘accommodating’ intraocular lens implantation are unlikely to be sustained in the long-term.

What is the public value of government action? Towards a (new) pragmatic approach to values questions in public endeavours

There has been a resurgence of interest in values in recent public administration research, based on two distinct arguments. For different reasons, neither approach is likely to secure a robust normative basis for public endeavours. These reasons are assessed, using an alternative body of theory rooted in contemporary social theory that we term, 'new pragmatism'. New pragmatic ideas are deployed to critique the divorce of values from facts; the abstraction of values from concrete situations; the anthropocentric foundation to social choice; the poorly developed understanding of the process of governance, with its inherent pluralism; and the seeming reluctance to articulate principles of political discourse. © 2010 The Authors. Public Administration © 2010 Blackwell Publishing Ltd.

Controlling system uncertainty in sport and work

An applied psychological framework for coping with performance uncertainty in sport and work systems is presented. The theme of personal control serves to integrate ideas prevalent in industrial and organisational psychology, the stress literature and labour process theory. These commonly focus on the promotion of tacit knowledge and learned resourcefulness in individual performers. Finally, data from an empirical evaluation of a development training programme to facilitate self-regulation skills in professional athletes are briefly highlighted.

Improving “last mile” delivery performance to retailers in hub and spoke distribution systems

Purpose – The purpose of this paper is to investigate the “last mile” delivery link between a hub and spoke distribution system and its customers. The proportion of retail, as opposed to non-retail (trade) customers using this type of distribution system has been growing in the UK. The paper shows the applicability of simulation to demonstrate changes in overall delivery policy to these customers. Design/methodology/approach – A case-based research method was chosen with the aim to provide an exemplar of practice and test the proposition that simulation can be used as a tool to investigate changes in delivery policy. Findings – The results indicate the potential improvement in delivery performance, specifically in meeting timed delivery performance, that could be made by having separate retail and non-retail delivery runs from the spoke terminal to the customer. Research limitations/implications – The simulation study does not attempt to generate a vehicle routing schedule but demonstrates the effects of a change on delivery performance when comparing delivery policies. Practical implications – Scheduling and spreadsheet software are widely used and provide useful assistance in the design of delivery runs and the allocation of staff to those delivery runs. This paper demonstrates to managers the usefulness of investigating the efficacy of current design rules and presents simulation as a suitable tool for this analysis. Originality/value – A simulation model is used in a novel application to test a change in delivery policy in response to a changing delivery profile of increased retail deliveries.

Life cycle assessment in the food supply chain:a case study

This research aims at assessing the environmental impact of the poultry supply chain from cradle to grave using case study research and also life cycle assessment (LCA). While a limited number of generic poultry production LCA studies have been published, fewer yet assess the whole process of a specific organisation, none comparing the increased impact of further processing. Our results show that irrespectively of the impact assessment method utilised, the process of producing portions is considerably higher in total environmental impact due to the extra raw material required to produce the same mass into retail. Our research contributes to the growing number of LCA studies and could be used by practitioners for comparison against national and international averages. From a theoretical point of view, this research provides new insights into the relationship between vertically integrated supply chains and environmental performance which has not been examined in the past.

Applicability of non-modular assessment in construction management and allied undergraduate programmes:perspective of the academics involved

Undergraduate programmes on construction management and other closely related built environment disciplines are currently taught and assessed on a modular basis. This is the case in the UK and in many other countries globally. However, it can be argued that professionally oriented programmes like these are better assessed on a non-modular basis, in order to produce graduates who can apply knowledge on different subject contents in cohesion to solve complex practical scenarios in their work environments. The examples of medical programmes where students are assessed on a non-modular basis can be cited as areas where this is already being done. A preliminary study was undertaken to explore the applicability of non-modular assessment within construction management undergraduate education. A selected sample of university academics was interviewed to gather their perspectives on applicability of non-modular assessment. General acceptance was observed among the academics involved that integrating non-modular assessment is applicable and will be beneficial. All academics stated that at least some form of non-modular assessment as being currently used in their programmes. Examples where cross-modular knowledge is assessed included comprehensive/multi-disciplinary project modules and creating larger modules to amalgamate a number of related subject areas. As opposed to a complete shift from modular to non-modular, an approach where non-modular assessment is integrated and its use further expanded within the current system is therefore suggested. This is due to the potential benefits associated with this form of assessment to professionally aligned built environment programmes

Szemléletbeli dilemmák a Public-Private Partnership menedzsmentjében = Management dilemmas in Public-Private Partnership projects

A tanulmány a Public-Private Partnership (PPP) immanens logikai kihívásai közül két kiemelt kérdést elemez: az állami fél közszolgálati-közigazgatási beágyazottságából eredő dilemmákat, valamint az állami és a magánfél eltérő kulturális hátteréből eredő feszültségek jellemzőit. A PPP projektek gyakorlati megvalósítása szempontjából e két kardinális kérdés kifinomult elméleti hátterébe nyújt bepillantást. A közszolgáltatási dilemmák közül azonosítja és tárgyalja a jogszerűség vs. eredményesség, a hatékonyság vs. eredményesség, a centralizáció vs. decentralizáció, a közérdek vs. egyéni szabadságjogok védelme, valamint a kormányzat kicsinyítése vs. jogbiztonság védelme, és a vállalkozói szemlélet vs. közszolgálatiság közti egyensúlyozás kihívásait. Az állami és az üzleti fél kulturális különbözőségének központi motívumaként a döntéshozatalbeli különbséget ragadja meg, és a bizalom szerepét hangsúlyozza a működőképes modell megtalálásának lehetőségeként. = This study analyses two cardinal issues of Public-Private Partnership (PPP) projects’ immanent challenges: the management dilemmas of public services/governance, and the tensions between the private and public parties due to their different cultural imbeddedness. It provides theoretical insights into these two issues of practical relevance. As public service management dilemmas, it identifies the trade-offs between rights vs. effectiveness, efficiency vs. effectiveness, centralization vs. decentralization, protecting the public interest vs. individual freedom, minimizing government vs. protecting human rights, the entrepreneurial approach vs. public service ethos. The study captures the cultural difference between the public and the private parties in their different approaches to decision making, while it concludes that the role of trust is key in finding feasible solutions for PPP models.

Versenyképesség és civil szerepvállalás a közigazgatás és a közszolgáltatások fejlesztésében (Competitiveness and civil contribution to the development of public administration and public services)

Az utóbbi évtizedek nemzetközi trendjei azt mutatják, hogy a civil szervezetek és a nonprofit szolgáltatók számottevő hatást gyakorolnak a versenyképesség alakulására. Ez a tanulmány azokat a formális és informális mechanizmusokat tekinti át, amelyeken keresztül a civil társadalom befolyásolja a közintézményi döntéseket és azok gyakorlati megvalósítását, hozzájárul a „government”-tôl a „governance” irányába való elmozduláshoz. Szintén képet ad arról az átalakulási folyamatról, amely a közszolgáltatások területén zajlik, s amelyből egyre markánsabban rajzolódik ki a közösségi kezdeményezésen alapuló, társadalmi ellenőrzés alatt működő nonprofit szolgáltatók és az állami szereplők közötti partneri viszony kialakulásának tendenciája. ____________ The international trends of the last decades have revealed that civil society organisations and nonprofit service providers have a significant impact on competitiveness. This paper gives an overview of the formal and informal mechanisms operated by civil society in order to keep public administration accountable, to influence public decisions and their implementation, thus moving from “government” towards “governance”. It also analyses the transition of public services, the more and more noticeable signs of an emerging partnership between the grassroots, community controlled service providing nonprofit organisations and the government actors.

A study of leadership behaviors for Breaking Ranks leaders in public secondary schools

This research will investigate what it will take to develop principals who will embrace the recommendations of reform as proposed by National Association of Secondary School Principals (NASSP, 1996) in the Breaking Ranks document. Breaking Ranks is based on the belief that it is within the dynamics of the school culture that principals must gain insight into strategies for improving the schools for which they are held responsible. Given this context, it is important to examine perspectives that are held by principals who lead schools that embrace the concepts of reform as proposed by NASSP, thereby, could be deemed “Breaking Ranks” schools. It is within these schools that the new role of the principal develops. NASSP has identified seven key recommendations for leadership development; “attributes that need nourishing” (p. 12) for the success of school reform. The seven recommendations are included in Breaking Ranks. ^ The purpose of this study is to identify and describe how principals put the seven recommendations into practice as they function in their schools. In addition, this study will gather information on the characteristics, support, skills, and training these principals identify as critical aspects and components of their success. This is a study of principal leadership at four high school sites where “Breaking Ranks” principals have been identified. ^ This research plan will be designed to utilize an inquiry-based process with a panel of experts and four “Breaking Ranks” principals. This study will describe: (1) how a panel of experts identify what they believe needs to be done in order to put the recommendations of the Breaking Ranks document into practice and their identification of principals who are breaking ranks; (2) how identified principals say they have been able to put the recommendations of the Breaking Ranks document into practice; (3) How both groups identify and describe: (a) the characteristics and behaviors of a “Breaking Ranks” principal; (b) the new leadership skills as described by the seven recommendations identified in the Breaking Ranks document; (c) the support necessary in order to meet the recommendations in the Breaking Ranks document; and (d) The training needed in order to become “Breaking Ranks” principals; and (4) how the process of creating “Breaking Ranks” principals can be described by experts who have studied it theoretically and principals who have demonstrated it in their schools. ^

Physical dynamic simulation of shipboard power system components in a distributed computational environment

Shipboard power systems have different characteristics than the utility power systems. In the Shipboard power system it is crucial that the systems and equipment work at their peak performance levels. One of the most demanding aspects for simulations of the Shipboard Power Systems is to connect the device under test to a real-time simulated dynamic equivalent and in an environment with actual hardware in the Loop (HIL). The real time simulations can be achieved by using multi-distributed modeling concept, in which the global system model is distributed over several processors through a communication link. The advantage of this approach is that it permits the gradual change from pure simulation to actual application. In order to perform system studies in such an environment physical phase variable models of different components of the shipboard power system were developed using operational parameters obtained from finite element (FE) analysis. These models were developed for two types of studies low and high frequency studies. Low frequency studies are used to examine the shipboard power systems behavior under load switching, and faults. High-frequency studies were used to predict abnormal conditions due to overvoltage, and components harmonic behavior. Different experiments were conducted to validate the developed models. The Simulation and experiment results show excellent agreement. The shipboard power systems components behavior under internal faults was investigated using FE analysis. This developed technique is very curial in the Shipboard power systems faults detection due to the lack of comprehensive fault test databases. A wavelet based methodology for feature extraction of the shipboard power systems current signals was developed for harmonic and fault diagnosis studies. This modeling methodology can be utilized to evaluate and predicate the NPS components future behavior in the design stage which will reduce the development cycles, cut overall cost, prevent failures, and test each subsystem exhaustively before integrating it into the system.