The impact of supply chain performance measurement systems on dynamic behaviour in supply chains

The amplification of demand variation up a supply chain widely termed ‘the Bullwhip Effect’ is disruptive, costly and something that supply chain management generally seeks to minimise. Originally attributed to poor system design; deficiencies in policies, organisation structure and delays in material and information flow all lead to sub-optimal reorder point calculation. It has since been attributed to exogenous random factors such as: uncertainties in demand, supply and distribution lead time but these causes are not exclusive as academic and operational studies since have shown that orders and/or inventories can exhibit significant variability even if customer demand and lead time are deterministic. This increase in the range of possible causes of dynamic behaviour indicates that our understanding of the phenomenon is far from complete. One possible, yet previously unexplored, factor that may influence dynamic behaviour in supply chains is the application and operation of supply chain performance measures. Organisations monitoring and responding to their adopted key performance metrics will make operational changes and this action may influence the level of dynamics within the supply chain, possibly degrading the performance of the very system they were intended to measure. In order to explore this a plausible abstraction of the operational responses to the Supply Chain Council’s SCOR® (Supply Chain Operations Reference) model was incorporated into a classic Beer Game distribution representation, using the dynamic discrete event simulation software Simul8. During the simulation the five SCOR Supply Chain Performance Attributes: Reliability, Responsiveness, Flexibility, Cost and Utilisation were continuously monitored and compared to established targets. Operational adjustments to the; reorder point, transportation modes and production capacity (where appropriate) for three independent supply chain roles were made and the degree of dynamic behaviour in the Supply Chain measured, using the ratio of the standard deviation of upstream demand relative to the standard deviation of the downstream demand. Factors employed to build the detailed model include: variable retail demand, order transmission, transportation delays, production delays, capacity constraints demand multipliers and demand averaging periods. Five dimensions of supply chain performance were monitored independently in three autonomous supply chain roles and operational settings adjusted accordingly. Uniqueness of this research stems from the application of the five SCOR performance attributes with modelled operational responses in a dynamic discrete event simulation model. This project makes its primary contribution to knowledge by measuring the impact, on supply chain dynamics, of applying a representative performance measurement system.

Differences in market-oriented behaviour levels across firms' domestic and export marketing operations:a study of antecedents and consequences

Researchers are beginning to recognise that organisations often have different levels of market orientation across different aspects of their operations. Focusing on firms involved in export marketing, this study examines how market-oriented behaviour differs across firms' domestic and export marketing operations. In this respect, the study is the first of its kind since it investigates three main issues: (1) to what extent do differences exist in firms' levels of market-oriented behaviour in their domestic markets (i.e., their domestic market-oriented behaviour) and in their export markets (i.e., their export market-oriented behaviour), (2) what are the key drivers of such differences, and (3) what are the performance implications for firms of having different levels of domestic and export market-oriented behaviour. To shed light on these research questions, data were collected from 225 British exporting firms using a mail questionnaire. Structural equation modelling techniques were used to develop and purify measures of all construct of interest, and to test the theoretical models developed. The results indicate that many of businesses sampled have very different levels of market orientation in their domestic and exporting operations: typically, firms tend to be more market-oriented in their domestic markets relative to their export markets. Several key factors were identified as drivers of differences in market orientation levels across firms' domestic and export markets. In particular, it was found that differences were more pronounced when: (i) interfunctional interactions between domestic marketing and export marketing are rare, (ii) when domestic and export marketing follow asymmetric business strategies, (iii) when mutual dependence between the functions is low, (iv) when one or other of the functions dominates the firm's sales, and (v) when there are pronounced differences in the degree to which the domestic and the export markets are experiencing environmental turbulence. The consequences of differences in market-oriented behaviour across firms' domestic and export markets were also studied. The results indicate that overall sales performance of firms (as determined by the composite of firms' domestic sales and export sales performance) is positively related to levels of domestic market-oriented behaviour under high levels of environmental turbulence in firms' domestic markets. However, as domestic market turbulence decreases, so to does the strength of this positive relationship. On the other hand, export market-oriented behaviour provides a positive contribution to firms' overall sales success under conditions of relatively low export market turbulence. As the turbulence in export markets increases, this positive relationship becomes weaker. These findings indicate that there are numerous situations in which it is sub-optimal for firms to have identical levels of market-oriented behaviour in their domestic and exporting operations. The theoretical and practical implications of these findings are discussed.

Typical case behaviour of spin systems in random graph and composite ensembles

This thesis includes analysis of disordered spin ensembles corresponding to Exact Cover, a multi-access channel problem, and composite models combining sparse and dense interactions. The satisfiability problem in Exact Cover is addressed using a statistical analysis of a simple branch and bound algorithm. The algorithm can be formulated in the large system limit as a branching process, for which critical properties can be analysed. Far from the critical point a set of differential equations may be used to model the process, and these are solved by numerical integration and exact bounding methods. The multi-access channel problem is formulated as an equilibrium statistical physics problem for the case of bit transmission on a channel with power control and synchronisation. A sparse code division multiple access method is considered and the optimal detection properties are examined in typical case by use of the replica method, and compared to detection performance achieved by interactive decoding methods. These codes are found to have phenomena closely resembling the well-understood dense codes. The composite model is introduced as an abstraction of canonical sparse and dense disordered spin models. The model includes couplings due to both dense and sparse topologies simultaneously. The new type of codes are shown to outperform sparse and dense codes in some regimes both in optimal performance, and in performance achieved by iterative detection methods in finite systems.