Are HRM practices related with patient mortality in NHS hospitals?:A study examining the underlying reasons for such an association

This thesis will report details of two studies conducted within the National Health Service in the UK that examined the association between HRM practices related to training and appraisal with health outcomes within NHS Trusts. Study one represents the organisational analysis of 61 NHS Trusts, and will report training and appraisal practices were significantly associated with lower patient mortality. Specifically, the research will show significantly lower patient mortality within NHS Trusts that: a) had achieved Investors in People accreditation; b) had a formal strategy document relating to training; c) had tailored training policy documents across occupational groups; d) had integrated training and appraisal practices; e) had a high percentage of staff receiving either an appraisal or updated personal development plan. There was also evidence of an additive effect where NHS Trusts that displayed more of these characteristics had significantly lower patient mortality. Study one in this thesis will also report significantly lower patient mortality within the NHS Trusts where there was broad level representation for the HR function. Study two will report details of a study conducted to examine the potential reasons why HR practices may be related to hospital performance. Details are given of the results of a staff attitudinal survey within five NHS Trusts. This study examined will show that a range of developmental activity, the favourability of the immediate work environment (in relation to social support and role stressors) and motivational outcomes are important antecedents to citizenship behaviours. Furthermore, the thesis will report that principles of the demand-control model were adopted to examine the relationship between workplace support and role stressors, and workplace support, influence, and an understanding of role expectation help mitigate against the negative effects of work demands upon motivational outcomes.

Psychosoziale Merkmale der Arbeit, Überforderungserleben und Depressivität

Die vorliegende Studie untersuchte die im Job-Demand-Control-Support-Modell und Effort-Reward-Imbalance-Modell beschriebenen Tätigkeitsmerkmale in Bezug auf Depressivität in einer Stichprobe von 265 Erwerbstätigen. Anhand konfirmatorischer Faktorenanalysen wurden Gemeinsamkeiten und Unterschiede beider Modelle geprüft. Anschließend wurde die Bedeutung der nachweisbaren Tätigkeitsmerkmale für die Vorhersage von Depressivität getestet und untersucht, inwieweit die Effekte durch Überforderungserleben mediiert werden. Die Analysen zeigten, dass die Modelle sowohl gemeinsame (Arbeitsintensität bzw. berufliche Anforderungen) als auch distinkte Arbeitsmerkmale (Tätigkeitsspielraum, Arbeitsplatzsicherheit, beruflicher Status, soziale Anerkennung) erfassen. Hohe Arbeitsintensität, geringe Arbeitsplatzsicherheit und fehlende soziale Anerkennung standen in signifikantem Zusammenhang mit Depressivität. Anders als erwartet war der berufliche Status positiv mit Depressivität assoziiert, während für den Tätigkeitsspielraum keine signifikanten Effekte nachweisbar waren. Das Pfadmodell bestätigte sowohl direkte als auch durch Überforderungserleben vermittelte Zusammenhänge zwischen den Tätigkeitsmerkmalen und Depressivität (39 % Varianzaufklärung). Die Ergebnisse bieten eine Grundlage für die Identifizierung potenzieller Risikofaktoren für das Auftreten depressiver Symptome am Arbeitsplatz. This study examined the job characteristics in the Job-Demand-Control-Support Model and in the Effort-Reward Imbalance Model with regard to depression in a sample of 265 employees. First, we tested by means of confirmatory factor analysis similarities and differences of the two models. Secondly, job characteristics were introduced as predictors in a path model to test their relation with depression. Furthermore, we examined whether the associations were mediated by the experience of excessive demands. Our analyses showed the demand/effort component to be one common factor, while decision latitude and reward (subdivided into the three facets of job security, social recognition, and status-related reward) remained distinctive components. Employees with high job demands/effort, low job security, low social recognition, but high status-related rewards reported higher depression scores. Unexpectedly, status-related rewards were positively associated with depression, while we found no significant effects for decision latitude. The path models confirmed direct as well as mediation effects (through experienced excessive demands) between job characteristics and depression (39 % explained variance in depression). Our results could be useful to identify possible job-related risk factors for depression.

Aspects of the design and control of manufacturing systems subject to demand uncertainty

The recent explosive growth in advanced manufacturing technology (AMT) and continued development of sophisticated information technologies (IT) is expected to have a profound effect on the way we design and operate manufacturing businesses. Furthermore, the escalating capital requirements associated with these developments have significantly increased the level of risk associated with initial design, ongoing development and operation. This dissertation has examined the integration of two key sub-elements of the Computer Integrated Manufacturing (CIM) system, namely the manufacturing facility and the production control system. This research has concentrated on the interactions between production control (MRP) and an AMT based production facility. The disappointing performance of such systems has been discussed in the context of a number of potential technological and performance incompatibilities between these two elements. It was argued that the design and selection of operating policies for both is the key to successful integration. Furthermore, policy decisions are shown to play an important role in matching the performance of the total system to the demands of the marketplace. It is demonstrated that a holistic approach to policy design must be adopted if successful integration is to be achieved. It is shown that the complexity of the issues resulting from such an approach required the formulation of a structured design methodology. Such a methodology was subsequently developed and discussed. This combined a first principles approach to the behaviour of system elements with the specification of a detailed holistic model for use in the policy design environment. The methodology aimed to make full use of the `low inertia' characteristics of AMT, whilst adopting a JIT configuration of MRP and re-coupling the total system to the market demands. This dissertation discussed the application of the methodology to an industrial case study and the subsequent design of operational policies. Consequently a novel approach to production control resulted. A central feature of which was a move toward reduced manual intervention in the MRP processing and scheduling logic with increased human involvement and motivation in the management of work-flow on the shopfloor. Experimental results indicated that significant performance advantages would result from the adoption of the recommended policy set.

New measures of job control, cognitive demand and production responsibility

Recent research has highlighted several job characteristics salient to employee well-being and behavior for which there are no adequate generally applicable measures. These include timing and method control, monitoring and problem-solving demand, and production responsibility. In this article, an attempt to develop measures of these constructs provided encouraging results. Confirmatory factor analyses applied to data from 2 samples of shop-floor employees showed a consistent fit to a common 5-factor measurement model. Scales corresponding to each of the dimensions showed satisfactory internal and test–retest reliabilities. As expected, the scales also discriminated between employees in different jobs and employees working with contrasting technologies.

A coordinated control scheme for power demand changes in a PMSG based multi-terminal DC wind farm

Although maximum power point tracking (MPPT) is crucial in the design of a wind power generation system, the necessary control strategies should also be considered for conditions that require a power reduction, called de-loading in this paper. A coordinated control scheme for a proposed current source converter (CSC) based DC wind energy conversion system is presented in this paper. This scheme combines coordinated control of the pitch angle, a DC load dumping chopper and the DC/DC converter, to quickly achieve wind farm de-loading. MATLAB/Simulink simulations and experiments are used to validate the purpose and effectiveness of the control scheme, both at the same power level. © 2013 IEEE.

Impact of electric vehicles on GB electricity demand and associated benefits for system control

This paper investigates the impact that electric vehicle uptake will have on the national electricity demand of Great Britain. Data from the National Travel Survey, and the Coventry and Birmingham Low Emissions Demonstration (CABLED) are used to model an electrical demand profile in a future scenario of significant electric vehicle market penetration. These two methods allow comparison of how conventional cars are currently used, and the resulting electrical demand with simple substitution of energy source, with data showing how electric vehicles are actually being used at present. The report finds that electric vehicles are unlikely to significantly impact electricity demand in GB. The paper also aims to determine whether electric vehicles have the potential to provide ancillary services to the grid operator, and if so, the capacity for such services that would be available. Demand side management, frequency response and Short term Operating Reserve (STOR) are the services considered. The report finds that electric cars are unlikely to provide enough moveable demand peak shedding to be worthwhile. However, it is found that controlling vehicle charging would provide sufficient power control to viably act as frequency response for dispatch by the transmission system operator. This paper concludes that electric vehicles have technical potential to aid management of the transmission network without adding a significant demand burden. © 2013 IEEE.

Simulation of robot manipulator control strategies

The high capital cost of robots prohibit their economic application. One method of making their application more economic is to increase their operating speed. This can be done in a number of ways e.g. redesign of robot geometry, improving actuators and improving control system design. In this thesis the control system design is considered. It is identified in the literature review that two aspects in relation to robot control system design have not been addressed in any great detail by previous researchers. These are: how significant are the coupling terms in the dynamic equations of the robot and what is the effect of the coupling terms on the performance of a number of typical independent axis control schemes?. The work in this thesis addresses these two questions in detail. A program was designed to automatically calculate the path and trajectory and to calculate the significance of the coupling terms in an example application of a robot manipulator tracking a part on a moving conveyor. The inertial and velocity coupling terms have been shown to be of significance when the manipulator was considered to be directly driven. A simulation of the robot manipulator following the planned trajectory has been established in order to assess the performance of the independent axis control strategies. The inertial coupling was shown to reinforce the control torque at the corner points of the trajectory, where there was an abrupt demand in acceleration in each axis but of opposite sign. This reduced the tracking error however, this effect was not controllable. A second effect was due to the velocity coupling terms. At high trajectory speeds it was shown, by means of a root locus analysis, that the velocity coupling terms caused the system to become unstable.

The choice of the model in inventory control and the cost of sophistication

This thesis is concerned with the inventory control of items that can be considered independent of one another. The decisions when to order and in what quantity, are the controllable or independent variables in cost expressions which are minimised. The four systems considered are referred to as (Q, R), (nQ,R,T), (M,T) and (M,R,T). Wiith ((Q,R) a fixed quantity Q is ordered each time the order cover (i.e. stock in hand plus on order ) equals or falls below R, the re-order level. With the other three systems reviews are made only at intervals of T. With (nQ,R,T) an order for nQ is placed if on review the inventory cover is less than or equal to R, where n, which is an integer, is chosen at the time so that the new order cover just exceeds R. In (M, T) each order increases the order cover to M. Fnally in (M, R, T) when on review, order cover does not exceed R, enough is ordered to increase it to M. The (Q, R) system is examined at several levels of complexity, so that the theoretical savings in inventory costs obtained with more exact models could be compared with the increases in computational costs. Since the exact model was preferable for the (Q,R) system only exact models were derived for theoretical systems for the other three. Several methods of optimization were tried, but most were found inappropriate for the exact models because of non-convergence. However one method did work for each of the exact models. Demand is considered continuous, and with one exception, the distribution assumed is the normal distribution truncated so that demand is never less than zero. Shortages are assumed to result in backorders, not lost sales. However, the shortage cost is a function of three items, one of which, the backorder cost, may be either a linear, quadratic or an exponential function of the length of time of a backorder, with or without period of grace. Lead times are assumed constant or gamma distributed. Lastly, the actual supply quantity is allowed to be distributed. All the sets of equations were programmed for a KDF 9 computer and the computed performances of the four inventory control procedures are compared under each assurnption.

Cost effectiveness of production control systems

This thesis deals with the problems associated with the planning and control of production, with particular reference to a small aluminium die casting company. The main problem areas were identified as: (a) A need to be able to forecast the customers demands upon the company's facilities. (b) A need to produce a manufacturing programme in which the output of the foundry (or die casting section) was balanced with the available capacity in the machine shop. (c) The need to ensure that the resultant system enabled the company's operating budget to have a reasonable chance of being achieved. At the commencement of the research work the major customers were members of the automobile industry and had their own system of forecasting, from which they issued manufacturing schedules to their component suppliers, The errors in the forecast were analysed and the distributions noted. Using these distributions the customer's forecast was capable of being modified to enable his final demand to be met with a known degree of confidence. Before a manufacturing programme could be developed the actual manufacturing system had to be reviewed and it was found that as with many small companies there was a remarkable lack of formal control and written data. Relevant data with regards to the component and the manufacturing process had therefore to be collected and analysed. The foundry process was fixed but the secondary machining operations were analysed by a technique similar to Component Flow Analysis and as a result the machines were arranged in a series of flow lines. A system of manual production control was proposed and for comparison, a local computer bureau was approached and a system proposed incorporating the production of additional management information. These systems are compared and the relative merits discussed and a proposal made for implementation.

Design of a stock control methodology for use within an oil blending company

The thesis deals with the background, development and description of a mathematical stock control methodology for use within an oil and chemical blending company, where demand and replenishment lead-times are generally non-stationary. The stock control model proper relies on, as input, adaptive forecasts of demand determined for an economical forecast/replenishment period precalculated on an individual stock-item basis. The control procedure is principally that of the continuous review, reorder level type, where the reorder level and reorder quantity 'float', that is, each changes in accordance with changes in demand. Two versions of the Methodology are presented; a cost minimisation version and a service level version. Realising the importance of demand forecasts, four recognised variations of the Trigg and Leach adaptive forecasting routine are examined. A fifth variation, developed, is proposed as part of the stock control methodology. The results of testing the cost minimisation version of the Methodology with historical data, by means of a computerised simulation, are presented together with a description of the simulation used. The performance of the Methodology is in addition compared favourably to a rule-of-thumb approach considered by the Company as an interim solution for reducing stack levels. The contribution of the work to the field of scientific stock control is felt to be significant for the following reasons:- (I) The Methodology is designed specifically for use with non-stationary demand and for this reason alone appears to be unique. (2) The Methodology is unique in its approach and the cost-minimisation version is shown to work successfully with the demand data presented. (3) The Methodology and the thesis as a whole fill an important gap between complex mathematical stock control theory and practical application. A brief description of a computerised order processing/stock monitoring system, designed and implemented as a pre-requisite for the Methodology's practical operation, is presented as an appendix.

The micro-politics of operational adjustment:veto players and the consolidation of demand in the NHS

Recent reports about procurement within the NHS have been highly critical. One problem identified in the reports is the fragmentation of NHS demand across an unnecessarily large number of suppliers. This fragmentation is said to increase transaction costs, reduce opportunities for scale economies and reduce NHS leverage over suppliers. It has been suggested, therefore, that an important way of improving procurement in the NHS is the better consolidation of demand with a lower number of preferred suppliers. However, such a policy, because it will create ‘winners’ and ‘losers’ within NHS organisations, has political as well as technical and practical ramifications. In this article, the authors present a model, the Veto Players Model, in order to assist managers to address these political ramifications. In the article, the authors not only demonstrate the utility of this model with regard to demand consolidation policies, but also argue that the model provides useful lessons for change management initiatives more generally.

Fuzzy knowledge-based approach to treating uncertainty in inventory control

Inventory control in complex manufacturing environments encounters various sources of uncertainity and imprecision. This paper presents one fuzzy knowledge-based approach to solving the problem of order quantity determination, in the presence of uncertain demand, lead time and actual inventory level. Uncertain data are represented by fuzzy numbers, and vaguely defined relations between them are modeled by fuzzy if-then rules. The proposed representation and inference mechanism are verified using a large numbers of examples. The results of three representative cases are summarized. Finally a comparison between the developed fuzzy knowledge-based and traditional, probabilistic approaches is discussed.